【Objective】To explore the structure and evolution characteristics of cotton NLP transcription factors in the whole genome, and further understand their expressions patterns, so as to lay a foundation for the further function research and utilization of NLP genes. 【Method】The NLP transcription factor family members in the whole genomes of four cotton species, Gossypium arboreum (G. arboreum, Ga), Gossypium raimondii (G. raimondii, Gr), Gossypium barbadense (G. barbadense, Gb) and Gossypium hirsutum (G. hirsutum, GH), were identified using two strategies, BLASTP and HMM search. Further bioinformatics analysis was carried out on the confirmed cotton NLP family members. The molecular weights, theoretical isoelectric points and other physical and chemical properties were predicted using online software Expasy; the MEGA 7 software was used to build the phylogenetic tree; protein conservative motifs were analyzed through MEME website; online software GSDS 2.0 was used to analyze gene structures; TBtools was used to view the chromosome localizations; McscanX was used to analyze the replication genes of cotton NLP family members; the PlantCARE website was used to predict the cis-acting elements in the promoters of cotton NLP family genes. The heat maps of cotton NLP genes expression levels of different tissues and under abiotic stresses were drawn through TBtools to analyze the tissue expression characteristics and abiotic stresses response characteristics. The expressions of GHNLPs in cotton under nitrogen starvation and nitrogen resupply treatments were analyzed by RT-qPCR. 【Result】A total of 11, 11, 21 and 22 NLP members were screened from the four cotton protein databases of G. arboreum, G. raimondii, G. barbadense and G. hirsutum, respectively. These NLP family genes encoded 693-996 amino acids. The relative molecular masses ranged from 76.92-110.02 kDa and the theoretical isoelectric points were 5.13-7.77. The subcellular localization prediction results showed that almost all the NLP members located in the nucleus. Promoter analysis found a large number of cis-acting elements related to phytohormone and stress response. Phylogenetic analysis showed cotton NLPs were divided into three groups, I, II and III. Gene replication analysis showed that fragment replication was the main force for NLP members expansion in cotton. All the Ka/Ks values were less than 1, indicating that evolution of NLP family in cotton mainly underwent purification selection. The results of expression analysis also confirmed that GHNLPs responded to nitrogen starvation and nitrogen resupply. 【Conclusion】From the whole genome of G. arboreum, G. raimondii, G. barbadense, and G. hirsutum, 11, 11, 21 and 22 NLP transcription factor members were identified respectively. They had high conservatism and some degree of differences. The expression levels of GHNLPs changed significantly during nitrogen starvation and nitrogen resupply processes, which may play a role in the response of cotton to nitrate.

选用鲁棉研21号为供试材料，分别开展室内发芽试验和田间小区试验，以评估有效成分质量分数为0.2%的咯菌腈·精甲霜·噻呋种子处理悬浮剂（FS）药液浸种对棉花苗期病害和黄萎病的防治效果。室内发芽试验结果表明，该药剂浸种处理能够促进种子萌发，并提高种子活力。播种第4天发芽势达73.33%，播种第7天发芽率和发芽指数分别为91.33%和31.29，均显著高于清水浸种处理和空白对照。田间小区试验结果显示，播种前使用该药剂浸种能够提高出苗率，对苗期病害的防治效果达62.46%；播种后第90天和第105天对黄萎病的防效分别为37.21%和23.23%，均显著高于清水浸种处理。本研究初步表明，使用0.2%咯菌腈·精甲霜·噻呋FS药液浸种处理对棉花种子安全，能够促进种子萌发，并可有效防治棉花苗期病害和黄萎病。

Crop maturity is the comprehensive performance reflection of crop growth, development and maturation. It is usually expressed by the growth period or life cycle from seedling emergence to harvest. It is also a critical indicator of crop ecological adaptability. The selection of cotton varieties with appropriate maturity is an important prerequisite to ensure normal maturity, high yield, superior fiber quality, and timely harvest. Accurate evaluation of cotton crop maturity is an important basis for cotton cultivation management and genetic improvement. Due to the indeterminate growth characteristic of cotton, the evaluation of cotton crop maturity is complicated, and there are still controversies so far. This manuscript clarifies the concept of cotton crop maturity, and discusses its main influencing factors (genetic factors, environmental factors, and cultivation measures), and reviews predictors and methods used for cotton crop maturity evaluation based on growth characteristics (the first fruit branch node, fruit branch occurrence speed and flowering time interval, pre-frost seed cotton rate, etc.), growth process (growth period, physiological termination period, the number of fruit branches above cracked boll, early maturity index, etc.) and the comprehensive index. In the end, the following suggestions have been given: enhancing the innovation of evaluation predictors for cotton crop maturity, establishment of the evaluation system for cotton crop maturity, and creation of an innovative information collection system, which will provide theoretical and technical support for cotton simplified and mechanized production.

【Objective】The effects of mepiquat chloride (DPC) on the insecticidal protein contents in Bt (Bacillus thuringiensis) cotton shell under high temperature and drought stress were investigated to provide a theoretical reference for the Bt cotton breeding as well as high-yield and high-efficiency cotton cultivation.【Method】The study was undertaken on the Bt cotton cultivar Sikang 3 during the 2020 and 2021 growing seasons at the Yangzhou University Farm, Yangzhou, China. The potted cotton plants were exposed to high temperature and drought stress, and 20 mg·L^-1 DPC and water (CK) were sprayed to cotton plants. Seven days after treatment, the insecticidal protein content, α-ketoglutarate content, pyruvic acid content, glutamate synthase activity, glutamic oxaloacetic transaminase activity, soluble protein content, free amino acid content in boll shell were analyzed, and the transcriptome sequencing was performed. DESeq was used for differential gene analysis. The GO and KEGG pathway databases were used to analyze the differentially expressed genes involved in regulating the insecticidal protein content through DPC.【Result】Compared with the water treatment (CK), the insecticidal protein contents under DPC treatment increased by 4.7%-11.9%. In terms of carbon metabolism, the contents of α-ketoglutarate and pyruvic acid were increased by 46%-57% and 25%-29%, respectively. In terms of amino acid metabolism, the activities of glutamate synthase and glutamic oxaloacetic transaminase, and the contents of soluble protein and free amino acid were increased by 32%-44%, 30%-40%, and 28%, 22%-27%, respectively. The transcriptome analysis revealed that there were 7 542 upregulation genes and 10 449 downregulation genes for DPC vs water. The GO and KEGG analysis showed that the differentially expressed genes were mainly involved in biological process such as amino acid metabolism and carbon metabolism. The genes coding 6-phosphofructokinase, pyruvate kinase, glutamic pyruvate transaminase, pyruvate dehydrogenase, citrate synthase, isocitrate dehydrogenase, 2-oxoglutarate dehydrogenase, glutamate synthase, 1-pyrroline-5-carboxylate dehydrogenase, glutamic oxaloacetic transaminase, amino-acid N-acetyltransferase, and acetylornithine deacetylase were all significantly up-regulated. 【Conclusion】 Under the stress of high temperature and drought, the DPC treatment increased the contents of α-ketoglutarate and pyruvic acid, and improved the synthesis ability of aspartic acid, glutamic acid, pyruvate and arginine, then enhanced the insecticidal protein contents in boll shell by regulating the carbon and amino acid metabolism.

Map-based cloning is a classical and effective method to identify candidate genes for specific phenotypic variants. Map-based cloning of functional genes plays important roles in the innovative utilization of germplasm resources, molecular design breeding and improving breeding efficiency. In recent years, the whole-genome sequencing of Gossypium raimondii, Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense has been completed and improved. Map-based cloning has entered into a crucial period. In 2016, the dominant glandless gene Gl₂^e (GoPGF) was the first map-based cloning gene in cotton. So far, 20 qualitative traits genes and 5 quantitative traits genes have been identified by map-based cloning technology. In this paper, research progress was systematically reviewed in fiber, gland, nectary, leaf type, plant architecture, plant color, and fertility in terms of gene symbols, names, chromosomal positioning, and candidate genes. Moreover, map-based cloning strategies were systematically reviewed in mapping populations and bulked segregate analysis-sequencing (BSA-seq). With the reduction of sequencing cost and utilization of BSA-seq, it is believed that more and more genes will be cloned by map-based cloning technology. In addition, transformation and genome editing have been successfully used to evaluate the function of the candidate gene in the target interval. It is believed that map-based cloning could provide a theoretical basis and genetic resources for molecular design breeding in cotton.

Cotton is the most important cash crop in Xinjiang, and southern Xinjiang is the main cotton production area, which yield accounts for 80% of the whole Xinjiang. For a long time, the planting mode of "wet sowing and dry emergence" was widely adopted in the cotton areas of southern Xinjiang, which meant that in addition to conventional irrigation during the cotton growth period, winter irrigation and spring irrigation were also needed to play a role in pressing salt and improving soil moisture during the sowing period. However, with the continuous expansion of cultivated land area and the increasing shortage of water resources, the cotton production of southern Xinjiang began to try the cultivation method in northern Xinjiang of "dry sowing and wet emergence" to grow cotton, but the overall effect was not ideal. Through the literature review, this paper tries to explore the reasons for the ineffective implementation of the "dry sowing and wet emergence" cultivation method in southern Xinjiang, and puts forward possible solution strategies on this basis.

2020年和2021年新陆早79号在北疆早熟植棉区示范推广中早熟性突出，结铃性强，吐絮集中，含絮好，适宜机采，表现出较高的增产潜力。概述了新陆早79号的选育过程、品种特征特性、栽培管理技术要点及其高产创建实践。

介绍了陆地棉品种塔河2号在新疆南疆种植的产量和品质表现，并从选择土地、播期、合理密植、适量调控、不同生育时期田间管理等方面介绍了栽培技术要点，为其推广和应用提供技术支撑。

【Background】It is of great importance to improve the quality of cotton fiber to meet the improvement of cotton textile production and the pursue of people for high quality cotton. Fasciclin-like arabinogalactan proteins (FLAs) play an important role in the initial development of cotton fibers and secondary wall synthesis. 【Objective】Comprehensive identification and analysis of cotton FLA gene family members to reveal their common characteristics and specific expression patterns, provided a reference for the function study of FLAs in cotton fiber development.【Method】According to the whole genome data of cotton, members of FLA gene family were identified by HMMER3.0 and further verified by online softwares of Pfam and Smart. Physical and chemical properties and transmembrane domains of these proteins were analyzed by ExPASy and TMHMM. Phylogenetic tree construction, chromosome localization, collinearity analysis and protein conserved domain sequence alignment were conducted and displayed using GSDS, MCScanX, MEGA, MEME, TBtools and Jalview. Expression of FLA genes in different tissues were analyzed by cotton transcriptome data. Expression differences of GhFLAs in different developmental stages of ovules and fibers between different fiber quality materials was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Function of GhFLA05 was verified by virus induced gene silencing (VIGS). 【Result】A total of 41, 40, 20 and 21 FLA family members were identified in G.hirsutum, G. barbadense, G. arboreum and G. raimondii, respectively. The phylogenetic tree showed that cotton FLA proteins could be divided into four groups. Gene structure and motif composition were relatively conserved in each group. Further analysis of FLA proteins in Gossypium hirsutum showed that all 41 FLA members had 1-2 AGP-like glycosylation regions and 1-2 fasciclin-like domains (FAS), 37 of which contained signal peptide (SP) and 25 contained glycosylphosphatidylinositol anchored protein (GPI) anchoring signals. Subcellular localization showed that GhFLA05_D showing aggregated granules in the cytoplasm was probably localized in endoplasmic reticulum, and GhFLA18_A and GhFLA22 were expressed in cell membrane/wall, cytoplasm and nucleus. Transcriptome sequencing results showed that FLA proteins in Group A and B were mainly highly expressed in fibers, which may be involved in the process of cotton fiber elongation development and secondary wall thickening. In general, group A and B members had a similar expression pattern in two materials with significant differences in fiber quality and expressed mainly in the secondary wall development stage, especially in 20-25 DPA period. GhFLA05 exhibited specific expression at the secondary wall thickening stage with significant differences between two materials, which expressed with a high maximum value in earlier stage of secondary wall thickening stage in high specific strength material RIL229, suggesting GhFLA05 may take a part in the regulation of cotton fiber strength difference formation. The fiber strength and micronaire value decreased in GhFLA05 gene-silenced cotton plants by VIGS.【Conclusion】A sum of 122 FLA family members were identified in Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum and Gossypium raimondii, which could be divided into four groups. Members of different groups had high structural and functional similarities, and the genes related to cotton fiber development were identified. It was clarified that GhFLA05 specifically expressed in the secondary wall synthesis stage, and closely related to the difference in fiber strength of different upland cotton materials.

中棉113于2019年引种到北疆，在昌吉回族自治州和博尔塔拉蒙古自治州等地示范种植，平均666.7 m²籽棉产量达到400 kg甚至更高，机采条件下多地多年的纤维上半部平均长度超过30 mm，断裂比强度超过30 cN·tex^－1。介绍了中棉113作为机采棉在北疆引种示范以来的特征特性表现及高产优质栽培技术要点，为新疆棉花的高产高效提供技术指导。

Although the cotton of Xinjiang has achieved high quality and high yield, its technological leadership and influence are still insufficient. To figure out the key technologies of high-quality cotton production in Xinjiang which can reflect the technical characteristics of cotton production comprehensively and objectively so that other areas where cotton is grown can understand cotton production technology in Xinjiang and show level of cotton production to the world. In addition, this article is to summarize experience, strengthen the popularization and further maturing of advanced technology, improve the application efficiency, and promote the promotion of cotton production technology in Xinjiang to other cotton regions. This paper based on years of experimental data and research results, awards and patented achievements such as “Innovation and application of light and efficient key technologies in cotton industrialization in Xinjiang” “Seeding Protection Method in Cotton Precision Seeding Field in Xinjiang”, combined with literature review, academic exchanges, visits and research. This analysis is carried out according to the order and tightness with technology corresponding to the cotton growth process. A series of key technologies are summarized, including: the seminal seeding and the supporting seedling technology, cotton field short-term, dense, early group control technology, water and fertilizer integration technology, the whole process of tube harvest mechanization and its supporting technology, pest and disease control technology. The relatively perfect cotton production technology system in Xinjiang has been constructed through improvement, optimization, maturation, innovation and application of key technologies, so that the technical level of cotton production in Xinjiang has been greatly improved to cover less than 9% of the world's planted cotton area, harvest more than 20% of the world's cotton, and lead the world in terms of single production level, quality in the world, and the total production, single production, and commodity transfers have been maintained for 28 consecutive years for the first time in the country. The in-depth analysis of innovation, optimization and practicability of cotton production technology in Xinjiang can help cotton regions better understand the inevitability and advanced of high yield and quality of cotton in Xinjiang. Practice also proves that, with the support of a series of key technologies, cotton in Xinjiang has achieved high-quality production and has become the region with the highest per unit yield and mechanization of cotton in China, which means that its technology can guide production practice and promote application.

【Objective】β-tubulin is the basic structural unit of cotton fiber, regulates fiber cell morphogenesis, and plays a vital role in fiber development. But there is less understood how β-tubulin gene influenced the distinct characteristic of fiber quality traits in cotton. In this study, members of the β-tubulin gene family were identified in cotton, their expression profiles were analyzed, and role of β-tubulin genes were explored for fiber quality. 【Method】BLAST method was used to identify members of the β-tubulin gene family in the genomes of four cotton species. ProtParam tool was utilized to analyze physicochemical properties, MEGA7.0 to construct phylogenetic tree, Mapchart2.2 to draw chromosomal localization map, MEME to analyze conserved motif, and PlantCARE to analyze promoter cis-acting elements. Expression levels of β-tubulin genes were characterized by using transcriptome data from 39 studies on fiber development. Spearman correlation analysis was used to identify candidate genes for fiber quality traits. 【Result】Importantly, 36, 37, 19 and 18 β-tubulin genes were identified in the genomes of Gossypium hirsutum (AD₁), Gossypium barbadense (AD₂), Gossypium arboretum (A₂) and Gossypium raimondii (D₅), respectively. The number of β-tubulin genes in tetraploid cotton species is almost double than that of diploid cotton species. Phylogenetic analysis classified these genes into 5 main clusters. Phylogenetic and collinearity analysis revealed that β-tubulin genes in Gossypium barbadense is closely related to Gossypium arboretum and Gossypium raimondii as compared to Gossypium hirsutum. Furthermore, all genes have typical conservative domains with Tubulin and Tubulin-C. The genes physicochemical properties showed amino acids range from 421 to 508 with isoelectric point of 4.68 to 5.09. The analysis of promoter cis-acting elements identified growth responsive, hormone responsive, and stress responsive elements which showed β-tubulin mediates various mechanisms of cell growth regulation. Interestingly, cluster analysis on 36 β-tubulin gene expression profiles showed 42% genes in cluster П had dominant expression in fiber. In particular, 1, 6, and 11 β-tubulin genes exhibited significant correlation with fiber micronaire value, fiber strength, and fiber length, respectively. Four genes were found to influence fiber length and fiber strength traits simultaneously. 【Conclusion】A total of 110 β-tubulin gene family members were identified in the four cotton species. Their physicochemical properties and sequences of amino acids were highly conserved and the promoter sequence had diverse regulatory elements. This study characterized the expression profiles as well as molecular function of β-tubulin gene family in cotton fiber. Further discovered the potential candidate genes that probably regulate fiber quality traits in cotton. Our results may have great potential for cotton fiber quality improvement by genetic engineering.

[Objective] This study aims to characterize the GhROP6 and study its roles of resistance to Verticillium wiltin upland cotton (Gossypium hirsutum L.). [Method] The bioinformatics analysis was used to identify Rho-related guanosine triphosphatase from plants (ROP) genes in upland cotton. The chromosome distributions, expression pattern analysis of GhROP genes were investigated. The function of GhROP6 gene was studied by quantitative real-time polymerase chain reaction (qRT-PCR), virus-induced gene silencing (VIGS), plant genetic transformation and metabolism analysis. [Result] Totally, 28 ROP genes were identified in upland cotton. And the corresponding amino acid sequence contained the ROP protein specific structures, including four GTP/GDP binding domains, effector domain binding to downstream target proteins and variable C-terminal regions. Chromosomal mapping analysis showed that 24 ROP genes were symmetrically distributed in subgenome A and subgenome D, and 3 genes specifically distributed in subgenome D. qRT-PCR analysis showed that the transcript levels of GhROP6 varied in different organs, and showed higher expression level in petals, stigma, fiber of 10 days post anthesis. Meanwhile, the transcript level of GhROP6 was upregulated in cotton by methyl jasmonate (MeJA). Knock-down of GhROP6 through VIGS weakened the cotton resistance to Verticillium wilt, and reduced the expression of GhLOX1, GhOPR3-1, GhOPR3-3, GhAOC1, GhAOS involved in jasmonic acid (JA) synthesis, and the expression of GhMYC2 involved in JA signaling pathway, and the expression of GhCCR-1, GhF5H-1, GhCCoAOMT-2, and GhCCoAOMT-3 genes involved in lignin synthesis. However, constitutively activated GhROP6 in Arabidopsis enhanced the plants resistantce to V. dahliae. Further analysis showed that the contents of JA-isoleucine and lignin in transgenic Arabidopsis were higher than those of wild type. [Conclusion] GhROP6 may involve in the resistance of cotton to Verticillium wilt through JA synthesis and signaling pathway and lignin synthesis.

创棉513于2021年通过国家农作物品种审定委员会审定。从选育过程与方法、生物学特性、产量表现、纤维品质和抗病性等方面对其进行了介绍，并总结了主要的栽培技术措施。创棉513在西北内陆早熟棉区生育期124 d，株型较紧凑，Ⅱ式果枝，株高70.1 cm，霜前花率100%，抗枯萎病、耐黄萎病，纤维品质达到国家棉花品种审定标准Ⅱ型品种要求。2020年生产试验中，创棉513的666.7 m²籽棉、皮棉产量分别为394.9 kg、185.1 kg。

创棉518于2021年通过国家农作物品种审定委员会审定。简要介绍了该品种的选育过程、农艺性状、产量表现、纤维品质及主要栽培技术措施。创棉518在西北内陆棉区春播生育期118 d，株型紧凑，株高73.05 cm，第一果枝节位5.1；抗枯萎病，耐黄萎病；2020年生产试验中，创棉518每666.7 m²平均籽棉产量、皮棉产量和霜前皮棉产量分别为394.5 kg、186.2 kg、176.7 kg。纤维品质达国家棉花品种审定标准Ⅱ型品种要求。

【Objective】Exploring the genetic loci and related genes that control cottonseed size traits to lay a foundation for subsequent study on the molecular mechanism cottonseed size formation. 【Method】The upland cotton recombinant inbred line (RIL) population composed of 300 lines was used as the research material. Seven phenotypic traits including cottonseed index (SI), seed length-cutting acreage (SLA), seed length-cutting perimeter (SLP), seed length (SL), seed width (SW), length-width ratio (LWR) and seed roundness (SR) were evaluated in four environments. The RIL population was genotyped by liquid phase chip strategy. The high-quality single nucleotide polymorphism (SNP) markers and phenotypic data were subjected to perform genome-wide association study (GWAS), and quantitative trait nucleotides (QTNs) associated with cottonseed size-related traits were mined. The genetic effects of QTNs were analyzed to identify candidate genes. 【Result】Seven cottonseed size-related traits showed a continuous normal distribution in four environments, which expressed a sizable phenotypic variation. The coefficient of variation ranged from 1.82% to 10.70%. The influencing effect on trait formation were basically as genotype>environment>genotype × environment, indicating suitability for GWAS analysis of these results. Correlation analysis showed that the seed index was significantly correlated with SLA, SLP, SL and SW, and LWR was significantly correlated with SR, indicating the possible existence of pleiotropic loci. GWAS was performed using the 3VmrMLM model, and a total of 47 QTNs were associated with these seven traits. A total of 11 QTNs were associated on chromosome A07, of which three physical loci in the region of 71.99-72.87 Mb, A07:71993462, A07:72067994 and A07:72198802 were very close and simultaneously associated with SI, SLA, SLP, SL and SW in four environments. The average value of R2 between markers was>0.8 (P<0.001), showing a large linkage disequilibrium. Genetic effect analysis showed that there were two haplotypes in this region. Among these cottonseed size relating traits, haplotype Ⅱ and haplotype I were significantly different, indicating that these loci directly affected cottonseed size traits and could be used for molecular marker-assisted selection. The expression patterns of the genes in the interval were analyzed using TM-1 transcriptome data. The results revealed that Gh_A07G1767 was preferentially expressed and Gh_A07G1766 specifically expressed at the stage of cottonseed development. These results speculated that these genes may play an important role in the growth and development of cottonseed.【Conclusion】47 QTNs were identified, and two candidate genes related to cottonseed development were screened.

【Objective】The two main types of allotetraploid cotton that are currently cultivated are upland cotton, known for its high yield and good adaptability, and island cotton, which boasts excellent fiber quality but lower yield. EXO70, a vital subunit of the exocyst complex, plays a significant role in plant growth, development, and stress response. By identifying and analyzing members of the EXO70 gene family in upland and island cotton at the whole-genome level, and studying their functions in fiber development and environmental adaptation, we can shed light on the molecular basis for the differences in traits between these two varieties. 【Method】The reference sequences of EXO70 protein in Arabidopsis were obtained from the TAIR database. HMMER, ExPASy, MEME, TBtools, and other analysis tools were used to identify and analyze the members of EXO70 gene family in the genomes of upland cotton TM-1 and island cotton Hai7124. The similarities and differences in gene expression patterns, correlations with crucial agronomic traits, and stress responses of this family were systematically compared. 【Result】Through genome-level analysis of upland cotton and sea-island cotton, 54 EXO70 family members were identified in both upland and sea-island cotton, which could be divided into eight subgroups based on phylogenetic analysis. Orthologous genes between upland cotton and sea-island cotton can be paired one-to-one and are distributed across the 20 chromosomes of both species. The majority of the members have single exons, while 12 pairs of homologous genes displayed significant differences in the reading frame sequences. Most orthologous genes in Gossypium hirsutum and Gossypium barbadense display similar expression patterns, but differences in expression levels are observed during the same fiber development stage, such as GH_A04G1208 and its orthologous gene GB_A04G1253 in subgroup A. Single gene association analysis revealed that more genes were associated with fiber quality traits in sea-island cotton, while more genes were associated with yield traits and environmental adversity sensitivity in upland cotton. Some trait association differences resulted from genetic structural differences between Gossypium hirsutum and Gossypium barbadense. Under different stresses, upland cotton showed a significantly higher number of induced genes compared to sea-island cotton. 【Conclusion】The sequence structure and gene expression patterns of the EXO70 family were found to be relatively conserved in both upland and island cotton during the formation, differentiation, and domestication of tetraploid cotton. However, in terms of EXO70 family members, island cotton had more genes related to fiber quality traits, while upland cotton had more genes related to yield traits and exhibited greater sensitivity to environmental stress.

[Objective] The unmanned aerial vehicle (UAV) multi-spectral remote sensing technology was used to monitor the severity of cotton Verticillium wilt, which will provide theoretical guidance for the precise prevention and control of cotton Verticillium wilt. [Method] By analyzing the spectral characteristics of canopy in cotton field affected by Verticillium wilt, the best vegetation index, the best wavelength combination and the best time phase for multi-spectral identification of Verticillium wilt by UAV were selected. The images of cotton fields differing in the severity of Verticillium wilt were established based on the optimal time phase. Parallelepiped method, maximum likelihood method and support vector machine radial basis function classification method were used to classify and evaluate the accuracy of the images. [Result] The results showed that the canopy spectral reflectance of cotton plants differing with occurrence of Verticillium wilt increased obviously with the increase of wavelength at 710-760 nm, the spectral reflectance of cotton canopy decreased obviously with the aggravation of Verticillium wilt at the wavelength of 760-950 nm. With the aggravation of Verticillium wilt, the chlorophyll content of leaves, fresh mass of aerial tissue per plant, dry mass of aerial tissue per plant, plant water content and leaf area index of cotton plants were all decreased. The best vegetation index and best band combination for UAV multi-spectral remote sensing to identify cotton Verticillium wilt were difference vegetation index (DVI) and B_3-5-8 (the corresponding wavelengths are 550 nm, 656 nm and 800 nm). Mid to late August was the best time to identify the occurrence degree of cotton Verticillium wilt by UAV multi-spectral remote sensing. Support vector machine radial basis function classification method, best band combination B_3-5-8 and DVI integrated image had the highest classification accuracy for Verticillium wilt in cotton field (classification accuracy was 96.64%, and Kappa coefficient was 95.61%). The classification results of Verticillium wilt severity in cotton fields corresponded to the changes in canopy spectral reflectance and agronomic parameters of cotton plants, and were consistent with the field investigation results. [Conclusion] It is feasible to classify the severity of Verticillium wilt in cotton field by using support vector machine radial basis function classification method, optimal band combination B_3-5-8 and DVI integrated images. The results can provide theoretical ground for monitoring similar crop pests and diseases by remote sensing technology.

【Objective】 As an important negative transcriptional regulator in cotton MADS-box gene family, AGL16 plays an important role in resisting drought and salt stress. Virus-induced gene editing (VIGE) was used to screen sgRNAs that knockout the cotton GhAGL16 and verify the specificity of these sgRNAs, which laid a foundation for the creation of cotton agl16 mutants.【Method】 Three sgRNAs could knockout GhAGL16 were predicted based on the actual GhAGL16 genomic sequence cloned on subgroup A and D in cotton YZ-1; Three CLCrV-AtU6-26::GhAGL16-sgRNAs vectors were constructed based on the cotton leaf crumple virus (CLCrV)-mediated VIGE system; The expression of Cas9 in Cas9 over-expression (Cas9-OE) plants was detected by qPCR to determine whether Cas9 was stably genetically expressed; Three CLCrV-AtU6-26::GhAGL16-sgRNAs vectors were transformed respectively into Cas9-OE cotton cotyledons and detected the mutations of the three targets by PCR/RE; The secondary structures of three GhAGL16-sgRNAs were analyzed by bioinformatics; Hi-TOM high-throughput sequencing was performed on mutant plants to determine the efficiency of gene editing. Meanwhile, the off-target rate of GhAGL16-sgRNA2 mutant plants were identified to detect the specificity of gene editing.【Result】 Three sgRNAs capable of simultaneously knocking out GhAGL16-A and D subgroups were successfully constructed. The detection results of Cas9 expression showed that Cas9 was stably expressed in different Cas9-OE cotton plants. PCR/RE mutation detection results showed that GhAGL16-sgRNA2 could be effectively used for the knockout of GhAGL16. Different mutation types with base deletions appeared at the target sites of cotton subgroups A and D, while GhAGL16-sgRNA1 and GhAGL16-sgRNA3 were two invalid sgRNAs. The secondary structure analysis results of three GhAGL16-sgRNAs indicated that GhAGL16-sgRNA1 and GhAGL16-sgRNA3 might have a phenomenon that the guide sequence was easy to pair with other sequences and difficult to unwind, which interfered with the recognition of the target site by the guide sequences and lead to the invalid sgRNA. To further quantify the editing efficiency of GhAGL16-sgRNA2 on GhAGL16, the mutation detection results of each Cas9-OE plant transformed with CLCrV-AtU6-26::GhAGL16-sgRNA2 showed that six of the nine Cas9-OE plants were mutated, with a mutation efficiency of 66.67%. In addition, Hi-TOM high-throughput sequencing results showed that the editing efficiency of GhAGL16-sgRNA2 for GhAGL16 was 13.69%-54.42%. The off-target identification results showed that no off-target phenomenon was detected at the four predicted off-target sites, indicating that GhAGL16-sgRNA2 not only has high gene editing efficiency, but also has specific gene editing specificity.【Conclusion】 A sgRNA that can effectively knocking out the GhAGL16 was obtained by transforming Cas9-OE cotton using the CLCrV-mediated VIGE system, providing an ideal sgRNA for creating cotton agl16 mutants.

[Objective] A model for estimating the quantity of seedlings in drip-irrigated cotton using color characteristics and morphological characteristics of unmanned aerial vehicle (UAV) image data was constructed to provide a theoretical basis for accurate management in cotton field. [Methods] The experiment was carried out in 2020-2021 and the cultivar Lumianyan 24 was used in the experiment. Three different planting densities were set as follow: low density (D1, 6.9 × 10⁴ plant·hm^-2), medium density (D2, 13.8 × 10⁴ plant·hm^-2) and high density (D3, 24 × 10⁴ plant·hm^-2). The UAV images were obtained on the 25 days old cotton seedlings, and the vegetation indices (VIs) of red, green, and blue (RGB) and target morphological features were extracted from the acquired UAV images. Based on the selected independent variable according to the correlation analysis, the model to estimate the quantity of cotton seedlings was constructed using stepwise multiple regression, followed by the model validation. [Results] (1) Comparing the segmentation effects of extracting cotton targets by triangular greenness index (TGI), excess greenness index (ExG), and green-blue difference + modified excess greenness index (GBDI + MExG), all these three VIs had relatively good segmentation effects, while TGI showed the highest precision of segmentation of cotton targets. (2) Comparing the two cotton plant quantity estimation models constructed with the two feature parameters, the estimation model based on the target morphological features for cotton seedling (R²=0.935 5) is better than the estimation model based on the VI of RGB (R²=0.903 6). (3) The estimation accuracy of the VIs-based seedling quantity estimation model were 96.77%, 99.55%, and 95.95% at D1, D2 and D3 densities respectively, and the overall estimation accuracy was 98.47%; the estimation accuracy of the plant estimation model based on the target morphological features at D1, D2 and D3 densities were 99.98%, 99.21%, and 97.92% respectively, and the overall estimation accuracy was 99.21%. The accuracy of the plant number estimation model based on the target morphological characteristics was slightly higher than that of the plant number estimation model based on VIs, but both models had good estimation outcome under different planting densities. [Conclusion] Using the UAV based low-altitude remote sensing platform with the integration of high-resolution sensors, the quantity estimation models for the drip-irrigated cotton seedlings were constructed by color vegetation indices and morphological features of target plants. Both models can effectively and accurately identify and quantify the drip-irrigated cotton plants under mulching, providing technical support for subsequent precision management in cotton fields.

[Objective] The study aims to examine the rhizosphere soil enzyme activity and bacterial community response to foliar application of 1,1-dimethyl-piperidinium chloride (DPC) and sodium nitroprusside (SNP) at the cotton seedling stage, and to screen rhizoshpere events potentially involved in cotton seedling growth. [Method] An upland cotton line A201 was grown in nursery trays under a controlled environment. The treatment with DPC of 50 mg·L^-1 and SNP of 500 μmol·L^-1, respectively, was foliar-applied at the one-leaf-one-heart stage, and the treatment with deionized water application was selected as the control. The rhizosphere soil was sampled to quantify the activities of sucrase, urease, catalase, and alkaline phosphate at the three-leaf-one-heart stage. The rhizosphere bacteria composition examined by 16S rRNA sequence analysis. [Result] The root growth, stem diameter, and dry mass of whole cotton plant were significantly increased by the DPC and SNP treatments. The activities of urease and sucrase were significantly improved by the DPC treatment. SNP application significantly enhanced sucrase activity but significantly decreased urease activity, while DPC treatment and SNP treatment had no significant effect on the activities of catalase and alkaline phosphatase. DPC application increased the relative abundance of Patescibacteria and Simpson's diversity index of soil bacterial community, but reduced the relative abundances of Chloroflexi and Acidobacteriota and Shannon Wiener’s diversity index of soil bacterial community. The results of redundancy analysis on family and genus level showed that the abundances of Saccharimonadaceae and TM7a were higher in the DPC treatment; the abundance of Cellvibrionaceae was greater in the SNP treatment; the abundance of Rhizobiaceae was greater in the DPC and SNP treatments. The control exhibited greater Nitrospiraceae and Nitrospira abundances compared with the DPC and SNP treatments. Urease activity was positively correlated with Saccharimonadaceae and TM7a relative abundances. [Conclusion] DPC and SNP could promote the growth of cotton roots and aerial parts, and influence the soil enzyme activity and bacterial community composition in the rhizosphere.

棉花集“棉、粮、油、饲、肥、药、（建）材、能（源）”于一身，耐旱、耐盐碱、耐瘠薄，还可以在重金属污染的农田里替代粮食作物种植，修复土壤。论述了棉花的多功能利用，主要包括：服装家纺、油脂佳肴、化工军工、美容医药、造纸造币、饲料菌料、建材原料、燃料肥料、美景花艺，并总结了其综合利用效益。

对2022年新疆棉花生产、籽棉销售、加工销售、皮棉价格、棉花补贴等情况进行了汇总，归纳和分析了2022年度新疆棉花产业突出问题，并提出了相应建议，助力新疆棉花产业发展。

以棉花为主体，套种其他高产高效作物，能大幅增加农民收入。棉花套种花生、蔬菜模式，田间生态互补性强，技术成熟，操作方便，机械化程度高，综合效益好，是近年来商丘新发展的种植模式。介绍了豫东棉花套种花生、蔬菜（生菜）种植模式的田间配置方式、种植时间及田间管理技术等，以期通过该模式实现当地棉田一年多收和绿色高产优质高效。

Cotton has obvious heterosis, which is manifested in traits including yield, fiber quality, and resistance to diseases and insects. Hybrid seed production is a very important step in the utilization of cotton heterosis. Recently, as the cost of manual pollination in seed production increases year by year, the simplified, efficient, and low-cost seed production techniques have become an inevitable trend for future hybrid cotton development. The field practice shows that the use of cytoplasmic male sterile lines not only simplify the procedure of seed production but also save labor costs, so it has become a research hotspot in the utilization of crop heterosis. However, the sterile cytoplasm does have certain impacts on cotton morphogenesis, anther development, yield formation, fiber development, and have negative effects on cotton growth and development, thereby limiting the further promotion and utilization of “three-line (male sterile line, maintainer line, and restoring line)” hybrid cotton. In this paper, the effects of male sterile cytoplasm on the main traits of cotton and the molecular basis for its negative effects were systematically reviewed. And the potential ways to overcome the negative effects of male sterile cytoplasm in cotton were preliminarily discussed, which would provide new ideas for breeding and improvement of cotton cytoplasmic male sterile restorer lines and excellent “three-line” hybrids in the future.

【Objective】The objective of this study is to confirm the target traits and genetic stability of transgenic glyphosate- resistant cotton GGK2 and provide technical support for its commercialization.【Method】T₃, T₄, and T₅ transgenic cotton plants GGK2 were subjected to insertion site-specific PCR, Southern blot, ELISA, bioassays in the laboratory and field, analysis of target herbicide tolerance, and investigation of nutritional constituents.【Result】The results indicated that the target genes, GR79 EPSPS and GAT, were integrated into the cotton genome as single copies and stably inherited in GGK2 plants. In GGK2 cotton, GR79 EPSPS, GAT, and NPTⅡ proteins were expressed at different stages and in different tissues, with relatively high expression levels in the leaves. At the four-leaf stage, bud stage and boll opening stag, the expression levels in leaves were 128.7-192.4 µg·g^-1, 24.4-35.0 µg·g^-1, and 17.0-23.9 µg·g^-1 fresh weight for GR79 EPSPS, GAT, and NPTⅡ, respectively. In the field, transgenic cotton GGK2 tolerated up to four times the recommended medium dose of glyphosate application. No significant differences were observed in agronomic traits and nutritional constituents compared to the control, Coker312.【Conclusion】These data demonstrate that transgenic cotton GGK2 is genetically stable and highly resistant to herbicides. Therefore, it can be utilized for breeding high-glyphosate- resistant commercial cotton varieties.

棉花侧封土是相对于传统正封土播种而出现的新播种方式。近几年该技术受到广大植棉户的认可，在北疆应用范围较广，但在不同年份、不同地块，2种播种方式的棉花出苗表现存在差异。通过在棉花出苗期进行田间调查和资料查询，对2种播种方式的优缺点及应用条件作简单分析，为北疆棉花种植户选择适宜的播种方式提供参考。

新疆昌吉回族自治州（昌吉州）是我国主要的优质棉产地，推动昌吉州棉花产业快速有序发展对我国优质棉花产业的发展具有重要的意义。分析昌吉州的水资源匮乏、植棉成本偏高、棉花品种良莠不齐、棉花产业发展模式不适应当前高质量发展需求等困境，提出通过培育和规范种植优质棉种、加强优质棉集成技术攻关与推广应用、强化科技和社会服务支持、积极探索昌吉州棉花产业发展新模式、提升优质棉基地创建水平、加大财政投入和人才队伍建设等方面，打造棉花全产业链，实现棉花产业高质量发展。

辽棉54在辽宁特早熟植棉区春播生育期为127 d；植株较紧凑，呈塔形；铃卵圆形；出苗好，后期不早衰；结铃性好，吐絮畅且集中，含絮力适中，适宜机采；高抗枯萎病，抗黄萎病。2019―2020年在辽宁省棉花品种区域试验中，该品种平均666.7 m2籽棉、皮棉和霜前皮棉产量分别为199.405 kg、82.185 kg和77.370 kg。介绍了辽棉54的选育过程、特征特性、适宜种植区域及栽培技术要点。

棉花的品质受产地环境条件影响较大，且不同产地棉花的进口关税存在差异，致使我国进口原棉产地欺诈现象屡见不鲜。为了维护国家及进出口企业利益，亟待寻找合适的方法对棉花产地进行鉴别。目前农产品的多种产地溯源技术较为成熟，然而在棉花原产地溯源中的实际应用还较少。对同位素质谱分析技术、近红外光谱分析技术、化学计量学分析等目前国内外产地溯源主流技术的原理、特点及其在棉花产地溯源中的应用进行了分析，以期为棉花产地鉴别技术的发展提供思路。

【Objective】 Weeds are one of the factors limiting cotton growth in cotton production, which not only competes with cotton for nutrition, water, and light, affecting the growth and development of cotton but also the yield and quality of cotton. The aim of this study is to develop excellent cotton germplasms with high glyphosate tolerance by genetic engineering and provide technical support for the commercialization of glyphosate-tolerant cotton to realize chemical weed control and enhance the economic benefits of cotton production.【Method】 To construct the cotton transformation vector, the EPSPS gene 1174AALdico-2 from Deinococcus radiodurans was connected to the chloroplast transit peptide (CTP), 35S was used as the promoter, and the two target genes were linked in series. The target gene was transformed into the CCRI 49 by Agrobacterium tumefaciens in vivo transformation, and the positive transformants were obtained. The positive transgenic plants obtained were evaluated for glyphosate tolerance, molecular characterization, agronomic and economic traits, in order to obtain outstanding transgenic cotton germplasms with excellent glyphosate tolerance, using the recipient cultivar, CCRI 49, and the non-transgenic NON isolated from the transformants during selfing as the controls.【Result】 138 positive transformants were obtained by Agrobacterium tumefaciens in vivo transformation. All the transformants were tested for target gene PCR, Southern blot, Western blot, and ELISA detection etc., and 17 positive transformants with clear molecular characteristics and high expression of foreign genes were identified. Southern blot and nucleotide sequencing results revealed that there was great variation in insertion site and copy numbers among the 17 transformants. Among them, ZD131, ZD185, and ZD207 had single-copy insertion sites, and the foreign genes were located on D7, D13, and A12, respectively. The results of glyphosate tolerance identification revealed that the glyphosate tolerance of the three transformants, ZD131, ZD185, and ZD207, was stably inherited across three generations, and the glyphosate tolerance of the transformants was strong, with the ability to tolerate four times the recommended dose of glyphosate in the field. The agronomic and economic features assessment findings revealed that the ZD131, ZD185, and ZD207 grew properly and had excellent agronomic traits such as large boll, high lint percentage, and high boll setting, as well as their lint yield was higher than that of the receptor cultivar control and their fiber quality reached to the high-quality cotton level.【Conclusion】 The EPSPS gene 1174AALdico-2 from Deinococcus radiodurans connected with the chloroplast transit peptide, and the two gene tandem together was transferred into CCRI 49 by Agrobacterium tumefaciens in vivo transformation technology. After a series of screens, three outstanding transgenic glyphosate-tolerant germplasms, ZD131, ZD185, and ZD207, were obtained. This method not only improves cotton's glyphosate tolerance but also improves the agronomic and economic aspects of transgenic materials.

【Objective】The leaf area index (LAI) is a vital indicator for evaluating crop growth, photosynthesis, and transpiration. The objective of this study is to explore the cotton LAI estimation models based on multi-spectral data from drones at different growth stages and multiple growth stages, clarify the variation patterns of cotton LAI estimation models during different growth stages, and to provide a basis for real-time understanding of cotton growth and scientific field management tailored to local conditions. 【Method】The DJI Elf 4 multi-spectral UAV was used to acquire multi-spectral images and RGB images of cotton at budding stage, initial flowering stage, boll setting and open-boll stages. Five multi-spectral indices, namely normalized difference vegetation index (NDVI), normalized green difference vegetation index (GNDVI), normalized difference red-edge index (NDRE), leaf chlorophyll index (LCI), optimized soil adjusted vegetation index (OSAVI), and five color indices, namely modified green-red vegetation index (MGRVI), green-red vegetation index (GRVI), green leaf algorithm (GLA), excess red index (EXR), and visible atmospherically resistant vegetation index (VARI), were selected to build a data set for each growth stage of cotton and multiple growth stages of cotton growth, respectively. Combined with the punching method to obtain actual ground LAI data, the machine learning algorithms of partial least squares regression (PLSR), ridge regression (RR), random forest (RF), support vector machine (SVM) and back propagation (BP) were used to construct a cotton LAI prediction model. 【Result】The LAI of cotton exhibited an increasing and then decreasing pattern during the growth stage. Notably, the mean LAI values of cotton at the inner side of the budding stage, initial flowering stage, and boll setting stage were significantly greater than those at the lateral side (P<0.05). The selected indices exhibited significant correlations with each other across the periods (P<0.05). In general, the correlation between multi-spectral index and color index showed a decreasing trend as the growth stage progressed, and the selected indices were significantly correlated with cotton LAI in all stages (P<0.05), the correlation coefficients of multi-spectral index ranged from 0.35 to 0.85, and the correlation coefficients of color index ranged from 0.49 to 0.71, and those with a larger absolute value of the correlation coefficients were mostly multi-spectral indices, while those of the correlation coefficients of color index and cotton LAI were smaller. The estimated model performance results showed that the multi-spectral index was better than the color index in the cotton growth models, the predictive performance of the index models showed certain regularity with the change of growth, and NDVI was the optimal index for predicting cotton LAI. From the model results, the RF model and BP model obtained higher estimation accuracy under each growth stage. The LAI inversion model at the initial flowering stage had the highest accuracy, with the optimal model validation set R² of 0.809, MAE of 0.288, and NRMSE of 0.120. The optimal model validation set for the multiple growth stages had the R² of 0.386, MAE of 0.700, and NRMSE of 0.198. 【Conclusion】There are significant differences in LAI between the inner and lateral sides of cotton during the budding stage, initial flowering stage, and boll setting stage. NDVI emerged as the optimal index for predicting cotton LAI at all growth stages, with the RF and BP models demonstrating superior performance. The effectiveness of the multiple growth stages model was notably lower compared to that of the single-growth model, with the optimal index identified as GNDVI and the optimal model as BP. The initial flowering stage appeared to be the optimal window for predicting cotton LAI. These findings can provide theoretical basis and technical support for utilizing UAV remote sensing to monitor cotton LAI.

In order to investigate the change rule of cotton phenology under the background of climate change, the parameters of the cotton growth model COSIM were adjusted and verified to achieve localization. Using mathematical statistics and crop model simulation methods, the response and sensitivity of cotton phenological periods to climate change were analyzed. The results showed that from 1980 to 2019, the date of emergence, budding and flowering of cotton in Xinjiang were earlier by 0.5-7.0 d/10a, 0.1-5.8 d/10a, and 0.3-3.9 d/10a, respectively, and the date of boll opening was delayed by 0.1-4.7 d/10a. COSIM was used to simulate phenological changes of cotton, and the results were consistent with the actual changes. The RMSE of the actual and simulated values of the date of emergence, budding, flowering and boll opening was 0.9 d, 0.7 d, 0.6 d and 0.7 d, respectively. Under warmer climate (simulated warming 0.5℃, 1℃, 1.5℃ and 2℃ compared with the base climate condition of 1981—2010), the rate of growth and development of cotton increased and each phenological period became earlier. The date of emergence, budding, flowering and boll opening were earlier by 0-2 d, 1-9 d, 2-12 d and 3-31 d, respectively; the vegetative growth stage and reproductive growth stage were shortened by 0-6 d and 2-22 d, respectively. Therefore, through variety selection and technology adjustment, climate warming can give more potential productivity to cotton by utilizing the advantage of heat and avoiding disaster risk in the key phenological periods, in order to achieve high yield and efficiency of cotton production.

根据2023年初对山东省8个主产棉市的调查，2023年山东省棉花种植意向面积呈持平态势。对山东省2022年棉花生产情况和2023年植棉意向面积持平的原因进行了分析，并对促进山东棉花稳定恢复发展提出了建议。

Leaves are the main places for photosynthesis and organic synthesis of cotton.  Leaf shape has important effects on the photosynthetic efficiency and canopy formation, thereby affecting cotton yield.  Previous studies have shown that LMI1 is the main gene regulating leaf shape. In this study, the LMI1 gene (LATE MERISTEM IDENTITY1) was inserted into the 35S promoter expression vector, and cotton plants overexpressing LMI1(OE) were obtained through genetical transformation.  Statistical analysis of the biological traits of T₁ and T₂ populations showed that compared to wild type (WT), OE plants had significant larger leaves, thicker stems and significantly increased dry weight.  Furthermore, plant sections of the main vein and petiole showed that the number of cell in those tissues of OE plants increased significantly.  In addition, RNA-seq analysis revealed differential expression of genes related to gibberellin synthesis and NAC gene family (genes containing the NAC domain) in OE and WT plants, suggesting that LMI1 is involved in secondary wall formation and cell proliferation, and promotes stem thickening.  Moreover, GO (Gene Ontology) analysis enriched the terms of calcium ion binding, and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis enriched the terms of fatty acid degradation, phosphatidylinositol signal transduction system, and cAMP signal pathway.  These results suggested that LMI1 OE plants were responsive to gibberellin hormone signals, and altered messenger signal (cAMP, Ca²⁺) which amplified this function, to promote the stronger above ground vegetative growth.  This study found the LMI1 soared the nutrient growth in cotton, which is the basic for higher yield.

2020年在新疆维吾尔自治区沙湾县四道河子镇进行田间试验，研究叶面喷施锌肥、硅肥和硅锌复配肥对棉花农艺性状、产量及棉纤维品质的影响。供试品种为新陆早60号，设置3个叶面肥喷施处理：硫酸锌750 g·hm^－2（锌肥处理）、硅酸钾750 g·hm^－2（硅肥处理）、硅酸钾750 g·hm^－2＋硫酸锌750 g·hm^－2（硅锌肥复配处理），以清水处理为对照，测定其对棉花农艺性状、不同器官干物质质量、产量和纤维品质的影响。结果表明，与对照相比，盛花期锌肥处理导致株高显著下降，锌肥、硅肥和硅锌肥复配处理均导致吐絮期的第1果枝长度显著降低，而其他性状均与对照无显著差异。不同施肥处理可显著影响盛花期和吐絮期叶片、茎秆和生殖器官的干物质质量。其中，锌肥、硅锌肥复配处理盛花期及硅肥处理吐絮期的生殖器官干物质质量均显著高于对照。虽然各处理理论皮棉产量差异不显著，但锌肥、硅肥和硅锌肥复配处理的理论皮棉产量分别较对照增加8.08%、5.09%和4.63%。硅锌肥复配处理的综合纤维品质优于其他处理。相关研究结果可为硅肥和锌肥在当地棉田的施用提供一定的参考。

【Objective】 This study was conducted to investigate the effects of alternating high temperature and drought on the content of Cry1Ac protein in Bt cotton and the underlying physiological mechanism, so as to provide a reference for the safe and stable utilization of insect resistance of Bt cotton in production.【Method】 The conventional cultivar Sikang 1 (SK-1) and hybrid cultivar Sikang 3 (SK-3) were used in 2019 and 2020 in experimentally controlled greenhouse, Yangzhou University. From 7:00 am to 7:00 pm, two high-temperature treatments [34℃ (A1) and 38℃ (A2)] were imposed on cotton plants, followed by an optimum temperature 28℃ during the remaining night hours. There were two treatments for soil moisture content, which were 50% (B1) and 60% (B2) field capacity. The treatment with 32℃/28℃ and 75% field capacity was set as the control (CK). The leaf Cry1Ac protein content and its physiological mechanism were detected on 4, 7, and 10 days after stress (DAS), respectively.【Result】 Compared with CK, the Cry1Ac protein content all decreased under the stresses of high temperature and drought, and with the extension of the stress time, greater decrease was observed. The extent of decline for A1B2 was the smallest, followed by A1B1, while A2B1 and A2B1 were the largest. The Cry1Ac protein content under A1B2 was significantly lower than CK after 7 DAS, while the significant differences between A1B1, A2B2, A2B2 and CK were detected after 4 DAS. The Bt gene expression level, soluble protein (SP), free amino acid (aa) contents, nitrate reductase (NR), the glutamic pyruvic transaminase (GPT), glutamic oxaloacetate transaminase (GOT), glutamine synthetase (GS) and glutamate synthase (GOGAT) activities showed a downward trend. While the tannin content, the activities of protease and peptidase showed an upward trend. The correlation analysis and path analysis showed SP, aa, NR, GPT, GOT, GS, and GOGAT were positively correlated with Cry1Ac protein content. The tannin content, activities of protease, and peptidase were negatively correlated with Cry1Ac protein content. NR, GPT and GS could be key indices for the Cry1Ac protein content.【Conclusion】 The interaction of high temperature and drought resulted in the decrease of Cry1Ac protein content in Bt cotton, with greater decrease observed as the stress extended. There was no significant difference between the treatment with 34℃/28℃ and 60% field capacity and CK in 7-10 DAS. The reduction extent of Cry1Ac for alternating high temperature regime and drought decreased and the period was delayed. NR, GPT and GS could be key indices for the Cry1Ac protein content.

Cotton fiber is not only the most important raw material for textile industry, but also an ideal model for studying plant cell differentiation, elongation, and cell wall synthesis. The differentiation and development of cotton fiber is regulated by a complex and interrelated regulatory network. Transcription factors, functional genes, plant hormones, non-coding RNAs, and epigenetic modifications all play important regulatory roles during cotton fiber development. With the assembly, resequencing, and association analysis of different cotton genomes, more and more key factors regulating cotton fiber development have been uncovered, which is of great significance for further elucidating the molecular regulation mechanism of cotton fiber development and helping cotton biological breeding.

【Objective】 Thrips is a major pest in cotton fields in Xinjiang. The objective of this study is to select their dominated predatory natural enemies and assess the predation efficiency on thrips, and to provide scientific insights for the development of biocontrol on thrips in cotton fields.【Method】 The population dynamics of thrips and their predators in Korla cotton field in southern Xinjiang were systematically investigated by visual inspection within five-point sampling in different blocks from 2021 to 2022. Predators’ samples were collected at different growth stages of cotton fields and detected by molecular detection, DNA of the whole natural enemy was extracted first, and PCR amplification was performed using the specific primers of Thrips tabaci and Frankliniella intonsa to obtain the species information of thrips in various natural enemies, then the quantitative food web of predator-thrips was constructed, and the differences of related food web structure at different growth stages of cotton were compared. In addition, basing on the predator-prey functional response model, the predation function of different predators (including adults and juveniles) on thrips was evaluated in laboratory by setting the prey density of 50, 100, 200, 300 and 400 individuals per Petri dish.【Result】 The population density of thrips was low at the seedling and budding stages but was high at the flowering-bolling stage. Annual population peaks occurred from late-July to early-August. Basing on the population dynamic, Hippodamia variegata is the dominated predator for thrips that occurred across the seeding, budding, flowering and bolling stages, while Campylomma diversicornis is the dominated predator in the late of flowering-bolling stage. The results of molecular detection showed the detection rate of thrips was high in the gut of H. variegata in the whole growth period of cotton, the detection rate of thrips in the gut of Coccinella undecimpunctata at seeding-budding stage was high, and the detection rate in the gut of C. diversicornis was also high at flowering-bolling stage. The predatory function response in laboratory indicated the predation ability of different predators on F. intonsa increased with the increase of prey density, the predation function of the larvae of H. variegata, the nymph of C. diversicornis and the larvae of Chrysoperla carnea was consisted with the Holling-Ⅱ model, whereas the predation function of the adult, such as H. variegata and C. diversicornis was suited with the Holling-Ⅲ model; when high prey density of 400 individuals thrips per Petri dish was provided, the consumed number of thrips for the adult of H. variegata was significantly higher than the larvae, the adult and nymph of C. diversicornis and the larvae of C. carnea.【Conclusion】H. variegata is the dominant predator for thrips across the whole cotton growth period, and C. diversicornis is the dominant predator in the late of flowering-bolling stage. This study provides a scientific insight for the utilization of predators to suppress thrips in cotton fields in Xinjiang.