Background As the most widely cultivated fiber crop, cotton production depends on hybridization to unlock the yield potential of current varieties. A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits, such as high yield and fine fiber quality. In this study, the general combining ability (GCA) and specific combining ability (SCA) of yield and fiber quality of nine cotton parents (six lines and three testers) and eighteen F₁ crosses produced using a line × tester mating design were analyzed.
Results The results revealed significant effects of genotypes, parents, crosses, and interactions between parents and crosses for most of the studied traits. Moreover, the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes. The F₁ hybrids of (Giza 90 × Aust) × Giza 86, Uzbekistan 1 × Giza 97, and Giza 96 × Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics. Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield, while lint percentage showed the highest negative direct effect on seed cotton yield. Principal component analysis identified specific parents and hybrids associated with higher cotton yield, fiber quality, and other agronomic traits.
Conclusion This study provides insights into identifying potential single- and three-way cross hybrids with superior cotton yield and fiber quality characteristics, laying a foundation for future research on improving fiber quality in cotton.

Background Cotton (Gossypium hirsutum L.) is one of the most significant fibre and cash crops and plays an important role in Indian industrial and agricultural economies. However, over the years quantity and quality have been hampered by the pest leafhopper. Leafhopper alone has been shown to cause yield losses of up to 40%. In this study, screening and evaluation were performed to identify and categorize 100 cotton genotypes along with 5 checks as resistant, moderately resistant, sensitive and highly sensitive to leafhoppers.
Results A total of hundred genotypes were evaluated along with five checks for leafhopper resistance. Based on the screening results, a total of 19 genotypes were resistant to leafhoppers, which was on par with the findings of the check KC 3. The contents of total soluble sugar, total soluble protein, and total free amino acids were significantly positively correlated with the mean grade, whereas total phenols content and trichome density were significantly negatively correlated with the susceptibility grade. However, based on screening and biochemical analysis, the genotypes KC 2, JR-23, Samaru-26-T, D 4, TCH 1728, RS 253, and B-61-1862 exhibited high resistance to leafhopper.
Conclusion According to the findings of this study, choosing genotypes with high total phenolics content together with high trichome density and low contents of total soluble sugar, total soluble protein, and free amino acids may aid in the development of resistant genotypes.

Background Cotton is an economically important crop. It is crucial to find an effective method to improve cotton yield, and one approach is to decrease the abscission of cotton bolls and buds. However, the lack of knowledge of the genetic and molecular mechanisms underlying cotton boll abscission traits has hindered genetic improvements.
Results Pearson’s correlation analysis revealed a significant positive correlation between boll abscission rates 1 (AR1) and boll abscission rates 2 (AR2). A genome-wide association study was conducted on 145 loci that exhibited high polymorphism and were uniformly distributed across 26 chromosomes (pair). The study revealed 18, 46, and 62 markers that were significantly associated with boll abscission, fiber quality, and yield traits (P < 0.05), explaining 1.75%-7.13%, 1.16%-9.58%, and 1.40%-5.44% of the phenotypic variation, respectively. Notably, the marker MON_SHIN-1584b was associated with the cotton boll abscission trait, whereas MON_CGR5732a was associated with cotton boll abscission and fiber quality traits. Thirteen of the marker loci identified in this study had been previously reported. Based on phenotypic effects, six typical cultivars with elite alleles related to cotton boll abscission, fiber quality, and yield traits were identified. These cultivars hold great promise for widespread utilization in breeding programs.
Conclusions These results lay the foundation for understanding the molecular regulatory mechanism of cotton boll abscission and provide data for the future improvement of cotton breeding.

Background Globally, the cultivation of cotton is constrained by its tendency for extended periods of growth. Early maturity plays a potential role in rainfed-based multiple cropping system especially in the current era of climate change. In the current study, a set of 20 diverse Gossypium hirsutum genotypes were evaluated in two crop seasons with three planting densities and assessed for 11 morphological traits related to early maturity. The study aimed to identify genotype(s) that mature rapidly and accomplish well under diverse environmental conditions based on the two robust multivariate techniques called multi-trait stability index (MTSI) and multi-trait genotype-ideotype distance index (MGIDI).
Results MTSI analysis revealed that out of the 20 genotypes, three genotypes, viz., NNDC-30, A-2, and S-32 accomplished well in terms of early maturity traits in two seasons. Furthermore, three genotypes were selected using MGIDI method for each planting densities with a selection intensity of 15%. The strengths and weaknesses of the genotypes selected based on MGIDI method highlighted that the breeders could focus on developing early-maturing genotypes with specific traits such as days to first flower and boll opening. The selected genotypes exhibited positive genetic gains for traits related to earliness and a successful harvest during the first and second pickings. However, there were negative gains for traits related to flowering and boll opening.
Conclusion The study identified three genotypes exhibiting early maturity and accomplished well under different planting densities. The multivariate methods (MTSI and MGIDI) serve as novel approaches for selecting desired genotypes in plant breeding programs, especially across various growing environments. These methods offer exclusive benefits and can easily construe and minimize multicollinearity issues.

Background Understanding the mechanism of male sterility is crucial for producing hybrid seeds and developing sterile germplasm resources. However, only a few cytoplasmic male sterility (CMS) lines of cotton have been produced due to several challenges, like inadequate variation of agronomic traits, incomplete sterility, weak resilience of restorer lines, and difficulty in combining strong dominance. Therefore, the morphological and cytological identification of CMS in cotton will facilitate hybrid breeding.
Results Two F₂ segregating populations of cotton were constructed from cytoplasmic male sterile lines (HaA and 01A, maternal) and restorer lines (HaR and 26R, paternal). Genetic analysis of these populations revealed a segregation ratio of 3:1 for fertile to sterile plants. Phenotypic analysis indicated no significant differences in traits of flower bud development between sterile and fertile plants. However, sterile plants exhibited smaller floral organs, shortened filament lengths, and anther atrophy on the flowering day in comparison with the fertile plants. When performed scanning electron microscopy (SEM), the two F₂ populations revealed morphological variations in the anther epidermis. Cellular analysis showed no significant differences in pollen development before pollen maturation. Interestingly, between the pollen maturation and flowering stages, the tapetum layer of sterile plants degenerated prematurely, resulting in abnormal pollen grains and gradual pollen degradation.
Conclusion The results of this study suggest that fertility-restoring genes are controlled by a single dominant gene. Sterile plants exhibit distinctive floral morphology, which is characterized by stamen atrophy and abnormal anthers. Pollen abortion occurs between pollen maturity and flowering, indicating that premature tapetum degradation may be the primary cause of pollen abortion. Overall, our study provides a theoretical basis for utilizing CMS in hybrid breeding and in-depth investigation of the dominant configuration of cotton hybrid combinations, mechanisms of sterility, and the role of sterile and restorer genes.

Cotton, an important industrial crop cultivated in more than 70 countries, plays a major role in the livelihood of millions of farmers and industrialists. Cotton is mainly grown for its fiber, an economic component that can be differentiated from its epidermal cells in the outer integument of a developing seed. Fiber length, fiber strength, and fiber fineness are three main attributes that contribute to the quality of cotton fibers. Recent advancements in genomics have identified key genes, which are the most important factors that govern these three traits, can be introduced into cultivars of interest via gene editing, marker-assisted selection, and transgenics, thus the narrow genetic background of cotton can be addressed and its fiber quality traits can be enhanced. Over the past two decades, quantitative trait loci (QTLs) have been mapped for different fiber traits, approximately 1 850 QTLs have been mapped for fiber length, fiber strength, and fineness among which a few genes have been edited for quality improvement in cotton. In this background, the current review covers the development and the factors that influence these traits, along with the reported genes, QTLs, and the edited genomes for trait improvement.

Background Studies on genetic variation and combining ability are essential tools to employ the suitable breeding programme, particularly for hybrid production, to exploit the heterosis in cross-pollinated crops like cotton. Thus, combining ability studies in desi cotton (Gossypium arboreum L.) was carried out using 13 diverse parents through diallel mating design, evaluating 78 F₁ hybrids along with their parents, without reciprocals using Griffing’s and Hayman’s approaches.
Results Genotypes H 509, AC 3265, AKH 496, and PBN 565 exhibited superior per se performance, indicating their potential use as parents in future breeding programs to develop superior hybrids. The general combining ability (GCA) effect of the genotypes revealed that AC 3097 and AKA 13-SP1 were good general combiners for most traits in this study. Genotypes PBS 1127-SP1, AKH 496, H 509, N11-54-31-32, and AKA 13-SP1 exhibited strong combining ability, contributing to a significant specific combining ability (SCA) effect in seven selected crosses (AC 3265 × PBS 1127-SP1, AKH 496 × H 509, AKH 496 × AC 3097, PBS 1127-SP1 × N11-54-31-32, AC 3216 × AKA 13-SP1, H 503 × N11-54-31-32, and H 509 × AKA 13-SP1) for yield improvement. These crosses showed positive heterosis in a positive direction.
Conclusion From the present study, five genotypes (AC 3097, AKA 13-SP1, N11-54-31-32, AC 3265, and H 509) were identified as good general combiners for producing hybrids, and seven combinations showed a promising hybrid for future breeding programs.

Background Cotton is an important cash crop in China and a key component of the global textile market. Verticillium wilt is a major factor affecting cotton yield. Single nucleotide polymorphism (SNP) markers and phenotypic data can be used to identify genetic markers and loci associated with cotton resistance to Verticillium wilt. We used eight upland cotton parent materials in this study to construct a multiparent advanced generation inter-cross (MAGIC) population comprising 320 lines. The Verticillium wilt resistance of the MAGIC population was identified in the greenhouse in 2019, and the average relative disease index (ARDI) was calculated. A genome-wide association study (GWAS) was performed to discover SNP markers/genes associated with Verticillium wilt resistance.
Results ARDI of the MAGIC population showed wide variation, ranging from 16.7 to 79.4 across three replicates. This variation reflected a diverse range of resistance to Verticillium wilt within the population. Analysis of distribution patterns across the environments revealed consistent trends, with coefficients of variation between 12.25% and 21.96%. Families with higher ARDI values, indicating stronger resistance, were more common, likely due to genetic diversity and environmental factors. Population structure analysis divided the MAGIC population into three subgroups, with Group I showing higher genetic variation and Groups II and III displaying more uniform resistance performance. Principal component analysis (PCA) confirmed these divisions, highlighting the genetic diversity underlying Verticillium wilt resistance. Through GWAS, we identified 19 SNPs significantly associated with Verticillium wilt resistance, distributed across three chromosomes. The screening of candidate genes was performed on the transcriptome derived from resistant and susceptible cultivars, combined with gene annotation and tissue expression patterns, and two key candidate genes, Ghir_A01G006660 and Ghir_A02G008980, were found to be potentially associated with Verticillium wilt resistance. This suggests that these two candidate genes may play an important role in responding to Verticillium wilt.
Conclusion This study aims to dissect the genetic basis of Verticillium wilt resistance in cotton by using a MAGIC population and GWAS. The study seeks to provide valuable genetic resources for marker-assisted breeding and enhance the understanding of resistance mechanisms to improve cotton resilience against Verticillium wilt.

Background Cotton is a significant crop for fiber production; however, seed shape-related traits have been less investigated in comparison to fiber quality. Comprehending the genetic foundation of traits associated with seed shape is crucial for improving the seed and fiber quality in cotton.
Results A total of 238 cotton accessions were evaluated in four different environments over a period of two years. Traits including thousand grain weight (TGW), aspect ratio (AR), seed length, seed width, diameter, and roundness demonstrated high heritability and significant genetic variation, as indicated by phenotypic analysis. The association analysis involved 145 simple sequence repeats (SSR) markers and identified 50 loci significantly associated with six traits related to seed shape. The markers MON_DPL0504aa and BNL2535ba were identified as influencing multiple traits, including aspect ratio and thousand grain weight. Notably, markers such as HAU2588a and MUSS422aa had considerable influence on seed diameter and roundness. The identified markers represented an average phenotypic variance between 3.92% for seed length and 16.54% for TGW.
Conclusions The research finds key loci for seed shape-related traits in cotton, providing significant potential for marker-assisted breeding. These findings establish a framework for breeding initiatives focused on enhancing seed quality, hence advancing the cotton production.

Background Hybrid cotton enjoys overwhelming patronage among cotton farmers because of its superior yield capacity and fiber quality. However, various environmental factors affect its yield and fiber quality. This study aimed to assess 30 cotton hybrids for the stability of four traits (single-plant seed cotton yield, fiber upper half mean length (UHML), fiber strength, and micronaire) across three environments. Recent techniques, including genotype and genotype × environment (GGE) biplot, which provides a visual representation of performance and adaptability; weighted average absolute scores of the best linear unbiased predictions (WAASB), which balances the performance of the trait with stability; and multi-trait stability index (MTSI), which integrates multi-trait performance and stability, were used to analyze the stability of the four traits.
Results Analysis of variance revealed significant genotype and environment interactions for all the traits studied, highlighting the need for comprehensive stability analysis. The environment E2 was the most suitable for the evaluation of seed cotton yield, whereas E3 was suitable for the evaluation of UHML and fiber strength. A stable hybrid, H05 (TVH002 × MCU5), with superior performance for seed cotton yield and UHML, was identified based on the overall results from GGE and WAASB. The which-won-where bioplot showed that H25 (SVPR3 × MCU5) performed the best for seed cotton yield in E3, and H27 (Suraj × Sunantha) in E2 and E1. The hybrid H04 (TVH002 × CO14) in E1 and H30 (Suraj × MCU5) in E2 and E3 performed well for UHML. Similarly, H28 (Suraj × Suraksha) for E2 and E3 and H26 (Suraj × Subiksha) for E1 were the best performing in the case of fiber strength. Based on the MTSI, four promising hybrids, namely, H24 (SVPR3 × CO14), H09 (TVH2010 × CO14), H18 (MCU7 × Suraksha), and H29 (Suraj × CO14), were identified as stable with average performance for all four traits.
Conclusions The study identified a stable hybrid, H05 (TVH002 × MCU5), with superior performance for yield and UHML. The identified hybrids in this study hold significant potential for cultivation across Tamil Nadu, with a scope for further evaluation in diverse environments.

为研究喷施脱叶催熟剂对棉花轻简化区域试验品种产量性状以及纤维品质的影响，明确山东省棉花轻简化区域试验喷施脱叶催熟剂的合理方法，以2023年和2024年棉花轻简化区域试验品种为材料，于打顶后60 d喷施噻苯隆600 g/hm²+乙烯利3000 mL/hm²，以喷施等量清水为对照，分析脱叶催熟剂对不同棉花品种产量性状和纤维品质等指标的影响。结果表明，脱叶催熟剂对棉花轻简化区域试验品种的籽棉产量、纤维长度、纤维比强度、整齐度指数无显著影响，但不同品种间存在差异，籽棉产量较对照降低或持平的品种比例在2个年度均约为50%。脱叶催熟剂对轻简化管理棉花品种的单铃重和籽指均有极显著影响，单铃重较对照平均降低4.23%~6.0%，籽指较对照平均降低5.51%~8.31%；脱叶催熟剂对衣分、马克隆值有较大影响，且影响程度因年度和品种类型而异。方差分析发现，脱叶催熟剂与品种类型的互作对籽指有极显著影响，而对籽棉产量、衣分、纤维长度、纤维比强度、马克隆值无显著影响，对单铃重的互作效应受品种类型和气候条件的影响较大。综上所述，在当前试验条件下，合理喷施脱叶催熟剂对棉花轻简化区域试验品种的产量和纤维品质无显著负面影响，建议山东省棉花轻简化区域试验喷施脱叶催熟剂的时间为打顶后60 d，每公顷应用600 g的50%噻苯隆可湿性粉剂和3000 mL的40%乙烯利水剂进行脱叶催熟，具体应用还需结合品种特性和当年气候条件进行调整。

CRISPR/Cas 12a系统是一种高效的基因组编辑工具，在植物功能基因组学研究和农艺性状改良中得到了广泛应用。本研究利用棉花内源pGhαGloA启动子对CRISPR/Cas 12a系统进行了优化。利用该系统，在Pol II类型的pGhaGloA启动子的驱动下，构建了pGhRBE3-pGhαGloA-GhPGF载体，并进行了遗传转化。该载体在所有阳性转基因植株中均能有效工作，crRNA1靶位点的编辑效率高达93.37%，crRNA2靶位点的编辑效率高达88.24%，明显高于Pol III启动子-Ubi 6.7驱动的的pGhRBE3系统的编辑效率，表明Pol II启动子比Pol III启动子更适合于在棉花中表达多种sgRNA或crRNA。该载体的主要编辑类型呈现片段缺失，缺失片段大小在3-12 bp之间，编辑位点位于PAM下游第14 ~ 29位碱基。这些突变位点在T₀到T₂代均能稳定遗传，同时获得了3个GhPGF基因突变的DNA-Free株系，这些无棉酚或低酚棉花种质将对棉籽油/饼的健康生产起重要用。因此，pGhαGloA启动子驱动的CRISPR/Cas 12a系统可以在棉花中高效编辑靶标基因，为棉花功能基因组学和遗传改良提供了有力的工具。

为明确鲁西南地区蒜后直播棉适宜的缩节胺化控方案，以短季棉品种‘鲁棉551’为试材，采用单因素随机区组设计，设置3个处理，分别在现蕾期、初花期、盛花期和打顶7日后喷施缩节胺，喷施剂量(T1：0 g/hm²、0 g/hm²、75.0 g/hm²、105.0 g/hm²；T2：0 g/hm²、45.0 g/hm²、60.0 g/hm²、75.0 g/hm²；T3：15.0 g/hm²、30.0 g/hm²、60.0 g/hm²、75.0 g/hm²)，清水为对照(CK)，系统研究不同施用时期和用量对棉花农艺性状、干物质积累、产量及纤维品质的影响。结果表明：全生育期缩节胺总用量不变的前提下，随着缩节胺喷施时间分次前移能够显著抑制棉花株高，提高单株结铃数和单铃重，从而达到增产的效果，其中T3皮棉产量分别比T2、T1、CK增加3.8%、12.5%、30.8%，不同处理的产量表现为T3>T2>T1>CK，同时也能增加根系和蕾铃的干物质重，降低赘芽的干物质重，但对棉花纤维品质无显著影响。试验中T3处理的产量及农艺性状较优，综上，鲁西南地区蒜后直播棉采用“前轻后重、少量多次”的缩节胺化控策略，即现蕾期15.0 g/hm²、初花期30.0 g/hm²、盛花期60.0 g/hm²和打顶7日后75.0 g/hm²，可实现株型优化、干物质合理分配与产量提升，为当地短季棉优质高效生产提供技术支撑。

Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strategy to enhance agricultural productivity. In this article, we provide an overview of the progress made in the alternate cotton-peanut intercropping, specifically focusing on its yield benefits, environmental impacts, and the underlying mechanisms. In addition, we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment, pest management options, and the mechanisms of root-canopy interactions. This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production.

Background Light is a critical factor in plant growth and development, particularly in controlled environments. Light-emitting diodes (LEDs) have become a reliable alternative to conventional high pressure sodium (HSP) lamps because they are more efficient and versatile in light sources. In contrast to well-known specialized LED light spectra for vegetables, the appropriate LED lights for crops such as cotton remain unknown.
Results In this growth chamber study, we selected and compared four LED lights with varying percentages (26.44%-68.68%) of red light (R, 600-700 nm), combined with other lights, for their effects on growth, leaf anatomy, and photosynthesis of cotton seedlings, using HSP lamp as a control. The total photosynthetic photon flux density (PPFD) was (215 ± 2) μmol·m^-2·s^-1 for all LEDs and HSP lamp. The results showed significant differences in all tested parameters among lights, and the percentage of far red (FR, 701-780 nm) within the range of 3.03%-11.86% was positively correlated with plant growth (characterized by leaf number and area, plant height, stem diameter, and total biomass), palisade layer thickness, photosynthesis rate (P_n), and stomatal conductance (G_s). The ratio of R/FR (4.445-11.497) negatively influenced the growth of cotton seedlings, and blue light (B) suppressed stem elongation but increased palisade cell length, chlorophyll content, and P_n.
Conclusion The LED 2 was superior to other LED lights and HSP lamp. It had the highest ratio of FR within the total PPFD (11.86%) and the lowest ratio of R/FR (4.445). LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.

Background Water deficit is an important problem in agricultural production in arid regions. With the advent of wholly mechanized technology for cotton planting in Xinjiang, it is important to determine which planting mode could achieve high yield, fiber quality and water use efficiency (WUE). This study aimed to explore if chemical topping affected cotton yield, quality and water use in relation to row configuration and plant densities.
Results Experiments were carried out in Xinjiang China, in 2020 and 2021 with two topping method, manual topping and chemical topping, two plant densities, low and high, and two row configurations, i.e., 76 cm equal rows and 10+66 cm narrow-wide rows, which were commonly applied in matching harvest machine. Chemical topping increased seed cotton yield, but did not affect cotton fiber quality comparing to traditional manual topping. Under equal row spacing, the WUE in higher density was 62.4% higher than in the lower one. However, under narrow-wide row spacing, the WUE in lower density was 53.3% higher than in higher one (farmers’ practice). For machine-harvest cotton in Xinjiang, the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m^-2 or equal rows with 18 plants m^-2.
Conclusion： The plant density recommended in narrow-wide rows was less than farmers’ practice and the density in equal rows was moderate with local practice. Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.

Background Natural and synthetic plant growth regulators are essential for plant health, likewise these regulators also play a role in increasing organic production productivity and improving quality and yield stability. In the present study, we have evaluated the effects of foliar applied plant growth regulators, i.e., moringa leaf extract (MLE) and mepiquat chloride (MC) alone and in combination MC and MLE on the conventional cotton cultivar (CIM 573) and transgenic one (CIM 598). The growth regulators were applied at the start of bloom, 45 and 90 days after blooming.
Results The application of MC and MLE at 90 days after blooming significantly improved the relative growth rate, net assimilation rate, the number of bolls per plant, and seed cotton yield. Likewise, the combined application of MLE and MC at 90 days after blooming significantly boosted the nitrogen uptake in locules, as well as the phosphorus and potassium uptake in the leaves of both cotton cultivars. The application of MLE alone has considerably improved the nitrogen uptake in leaves, and phosphorus and potassium contents in locules of Bt and conventional cotton cultivars. Similarly, Bt cotton treated with MLE at 90 days after blooming produced significantly higher ginning out turn and oil contents. Treatment in combination (MLE + MC) at 90 days after blooming produced considerably higher micronaire value, fiber strength, and staple length in conventional cultivar.
Conclusion The natural growth enhancer, MLE is a rich source of minerals and zeatin, improving the nutrient absorption and quality of cotton fiber in both conventional and Bt cotton cultivars.

Background Cotton (Gossypium hirsutum L.), adapted to tropical and subtropical regions of the world, is highly sensitive to low temperatures throughout its life cycle. The objective of this study was to evaluate the mitigating effects of different doses of animal-derived (0.25%, 0.50%, and 1.00% Isabion® ), seaweed-based (0.165%, 0.330%, and 0.660% Proton®) biostimulants, as well as a copper (Cu)-containing fungicide application, on cotton cultivar Lazer seedlings at the four true leaves (V4) stage. The plants were exposed to a low temperature of 5 °C for 48 h, and the changes in morphological (seedling fresh and dry weight, plant height, and stem diameter) and physiological parameters (leaf temperature, chlorophyll content, relative water content, electrolyte leakage, and relative injury) were examined.
Results The results revealed that chilling stress reduced plant growth, while biostimulants helped protect the plants and overcome the adverse effects of chilling. Under chilling stress, there was a considerable reduction in seedling fresh weight (SFW), seedling dry weight (SDW), plant height (PH), stem diameter (SD), leaf temperature (LT), and relative water content (RWC). Cotton seedlings treated with the animal-derived biostimulants showed significantly enhanced SFW, SDW, PH, SD, LT, chlorophyll content (Chl), electrolyte leakage (EL), and relative injury (RI), although there were no positive changes in RWC. No significant differences in the morphological traits were observed among the doses of seaweed biostimulants. For SDW, PH, EL, and RI, the best results were obtained with the application of a fungicide containing copper.
Conclusion These results show the efficiency of the biostimulant and fungicide treatments in mitigating low-temperature stress in cotton seedlings. Applying a copper-containing fungicide to cotton seedlings helped to counteract the negative effects of low-temperature stress and to protect the plants from damage by maintaining electrolyte balance. Among the biostimulant applications, all levels of animal-derived biostimulant applications, as well as the 0.660% level of the seaweed-derived biostimulant, led to increased tolerance of cotton plants to chilling stress.

Lessons learned from past experiences push for an alternate way of crop production. In India, adopting high density planting system (HDPS) to boost cotton yield is becoming a growing trend. HDPS has recently been considered a replacement for the current Indian production system. It is also suitable for mechanical harvesting, which reducing labour costs, increasing input use efficiency, timely harvesting timely, maintaining cotton quality, and offering the potential to increase productivity and profitability. This technology has become widespread in globally cotton growing regions. Water management is critical for the success of high density cotton planting. Due to the problem of freshwater availability, more crops should be produced per drop of water. In the high-density planting system, optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs. Deficit irrigation is a tool to save water without compromising yield. At the same time, it consumes less water than the normal evapotranspiration of crops. This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation. Based on the current research and combined with cotton production reality, this review discusses the application and future development of deficit irrigation, which may provide theoretical guidance for the sustainable advancement of cotton planting systems.

Machine picking in cotton is an emerging practice in India, to solve the problems of labour shortages and production costs increasing. Cotton production has been declining in recent years; however, the high density planting system (HDPS) offers a viable method to enhance productivity by increasing plant populations per unit area, optimizing resource utilization, and facilitating machine picking. Cotton is an indeterminate plant that produce excessive vegetative growth in favorable soil fertility and moisture conditions, which posing challenges for efficient machine picking. To address this issue, the application of plant growth retardants (PGRs) is essential for controlling canopy architecture. PGRs reduce internode elongation, promote regulated branching, and increase plant compactness, making cotton plants better suited for machine picking. PGRs application also optimizes photosynthates distribution between vegetative and reproductive growth, resulting in higher yields and improved fibre quality. The integration of HDPS and PGRs applications results in an optimal plant architecture for improving machine picking efficiency. However, the success of this integration is determined by some factors, including cotton variety, environmental conditions, and geographical variations. These approaches not only address yield stagnation and labour shortages but also help to establish more effective and sustainable cotton farming practices, resulting in higher cotton productivity.

Cotton, a crucial commercial fibre crop, depends heavily on seed-associated characteristics like germination rate, vigour, and resistance to post-harvest deterioration for both production and lint quality. Serious cellular damage during post-harvest processes such as delinting, prolonged seedling emergence periods, decreased viability, increased susceptibility to infections, and lipid peroxidation during storage pose serious problems to seed quality. The performance of seeds and total crop productivity are adversely affected by these problems. Traditional methods of seed improvement, like physical scarification and seed priming, have demonstrated promise in raising cotton seed vigour and germination rates. Furthermore, modern approaches including plasma therapies, magnetic water treatments, and nanotechnology-based treatments have shown promise in improving seed quality and reducing environmental stresses. By offering sustainable substitutes for conventional approaches, these cutting-edge procedures lessen the need for fungicides and other agrochemicals that pollute the environment. This review explores various conventional and emerging strategies to address the detrimental factors impacting cotton seed quality. It emphasizes the importance of integrating classical and advanced approaches to enhance germination, ensure robust crop establishment, and achieve higher yields. In addition to promoting sustainable cotton production, this kind of integration helps preserve the ecosystem and create resilient farming methods.

Premature senescence in Bacillus thuringiensis (Bt) cotton has emerged as a significant challenge to the formation and realization of fiber yield and quality since its commercialization in 1997. Initially, premature senescence was thought to be an inherent trait associated with the Bt gene. However, subsequent research and practice have demonstrated that it is not directly linked to the Bt gene but rather results from a physiological imbalance between the sink and source, as well as between the root and shoot in Bt cotton. This short review provides an overview of the causes, mechanisms, and control measures for premature senescence in Bt cotton. It offers valuable insights for future research and the sustainable application of transgenic crops.

Background Zinc (Zn), being the most deficient micronutrient, can largely limit plant growth and development on alkaline calcareous soil. Crop species and varieties within species differently require Zn for optimum productivity. The current study aimed to optimize Zn level and mode of application for better growth, yield, and fiber quality of cotton (Gossypium hirsutum L.). The experimental plan comprised a control group with no Zn application, three Zn levels through soil application, i.e. 5 mg·kg^-1 (SZn5), 10 mg·kg^-1 (SZn10), and 15 mg·kg^-1 (SZn15), two levels of foliar application including 0.5% (FZn0.5) and 1% (FZn1) Zn solution, and various combinations of soil plus foliar application. Two cotton cultivars, CIM-663 (Bt) and Cyto-124 (non-Bt) were used, and each treatment was replicated thrice.
Results Zinc nutrition caused a significant (P ≤ 0.05) improvement in growth, yield, physiological, and fiber quality characteristics of both cotton cultivars. All levels and modes of Zn application were found effective in improving cotton productivity on alkaline calcareous soil. However, integrated soil application and foliar spray showed superiority over sole soil or foliar application. Among different treatments, SZn15 + FZn1 caused the highest improvement in most of the observed growth and yield traits. The said treatment maximally increased the leaf Zn concentration by 270.5% and 218.4% with a subsequent increase in plant height 23.2% and 28.0%, monopodial branches 40.7% and 42.1%, sympodial branches 37.2% and 35.2%, seed cotton yield 32.5% and 36.6%, and lint yield 30.0% and 34.6% in CIM-663 and Cyto-124, respectively, compared with the control. SZn15 + FZn1 also caused the highest increase in relative water contents 32.6% and 22.4%, chlorophyll contents 92.0% and 67.1%, and stomatal conductance 112.8% and 100.8% in CIM-663 and Cyto-124, respectively, compared with the control. Among the fiber quality characteristics, fiber fineness was maximally improved by 19.7% and 15.9% in CIM-663 and Cyto-124, respectively, with SZn15 + FZn1 compared with the control. Leaf Zn concentration was positively correlated with fiber length (R² = 0.717 3), fiber strength (R² = 0.548 3), and fiber fineness (R² = 0.637 9) of both cotton cultivars grown with different levels and application modes of Zn. The benefit-cost ratio was remarkably improved with Zn nutrition, and the highest value of 1.64 was found in CIM-663 at SZn10 + FZn1 and SZn15 + FZn1.
Conclusion The plant growth, physiological, yield, and fiber quality characteristics of cotton cultivars were significantly improved with Zn supply at different levels and modes of application. SZn15 + FZN1 could be recommended to get optimum seed cotton yield and fiber quality of cotton on alkaline calcareous soil.

Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source. However, delayed sowing is unavoidable in mulch-free cultivation in ecological regions with a short frost-free period. Intercropping with cumin, which has a shorter growth period, served as an effective strategy to improve land use efficiency during the early growth stages of cotton. Therefore, a two-year field experiment was conducted to study the effects of intercropping cumin at the seeding rate of 2.5 (ID1), 3.85 (ID2), and 5.2 (ID3) kg·hm^-2 on cotton growth, interspecies competition, fiber quality, and water use efficiency (WUE), as well as system economic benefits under subsurface drip irrigation. Monocropping cotton was used as the control (CK) treatment.
Results At the initial flowering (IF) stage (the end of the co-growth period of cotton and cumin), cotton plant height in ID2 and ID3 treatments decreased by 5.93%-16.53% and 10.87%-31.11%, respectively, cotton stem diameter by 11.41%-14.25% and 3.37%-26.49%, respectively, and vegetative biomass by 14.46%-30.65% and 22.59%-49.91%, respectively, compared with CK treatment. With the increase in cumin density, the crop growth rate (CGR) and compensation effect in cotton tended to significantly decrease at the IF stage regardless of organs considered. For the non-co-growth period (after harvesting cumin), cotton reproductive organ biomass in ID2 and ID3 treatments increased by 4.09%‒14.61% at the boll opening stage, crop growth rate in reproductive organs by 20.74% and 74.26% from peak boll to boll opening stages compared with CK treatment, due to an enhancement of 19.09% and 49.30% in the compensation effect. Compared with ID1, the aggressivity treated by ID2 and ID3 decreased by 12.82%-46.34% and 17.95%-31.71%, respectively. However, owing to a greater number of green bolls in the upper canopy at the harvest stages in the ID3 treatment, the system production value (closely related to yield) treated by ID2 was 11.69%-16.89%, 6.56%-20.02%, and 16.48%-59.83% greater than that of the ID1, ID3, and CK treatments, respectively. This also led to the highest WUE and net profit under the ID2 treatment.
Conclusion Intercropping cumin with medium density improved the cotton biomass accumulation characteristics and increased resources such as land and water utilization efficiency and economic benefits through a stronger compensation effect after harvesting cumin under subsurface drip irrigation without mulch. This study not only provides alternatives to residual film pollution in arid cotton fields but also establishes a sustainable agro-ecological-economic planting paradigm by reducing plastic use and enhancing water and fertilizer use efficiency, holding significant implications for advancing resource-efficient agricultural systems.

Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton (Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cropping systems in two cotton-growing zones. Plough-based tillage plus incorporation of cover crop biomass (PTI), conservation agriculture with strip tillage (CA_ST), and conservation agriculture with no tillage (CA_NT) were compared with the reference plough-based tillage (PT). The objective was to identify morpho-physiological traits of cotton that increase yield in agroecological cropping systems. Our approach combined a field experiment and crop simulation model (CSM) of CROPGRO-Cotton to evaluate the effects of genotype (G) × environment (E) × management (M) interactions on seed cotton yield (SCY).
Results Cultivars Tamcot_camde and Okp768 and simulated ideotypes performed best in CA systems. Increased seed mass, large and thick leaves, and later maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits also resulted in better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes designed could increase SCY in Benin.
Conclusion A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good SCY in agroecological cropping systems. These results provide scientific evidence and useful knowledge for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.

Background Irrigation has been a strategy used to reduce losses due to drought, which combined with a good supply of nitrogen (N), can improve the protective system of cotton plants. The objective of this study was to investigate the effects of irrigated and rainfed cotton cultivation using different rates and sources of N. Cotton cultivation was carried out in Selvíria-MS field in the 2017/2018 harvest. The experiment was conducted in randomized blocks, which were designed in a 4 × 2 × 2 factorial scheme. The factors were composed of 0, 40, 80, and 150 kg·hm^-2 level of N, using two sources of N under rainfed and irrigated systems.
Results The provision of irrigation provided an increase in the levels of chlorophylls (Chl) a, Chl b, total Chl, carotenoids, pheophytin, leaf chlorophyll index (LCI), N content, nitrate (NO₃^-), sucrose (SUC), the number of vegetative and reproductive branches, boll mass, and seed cotton productivity. There was no effect of N sources on any of the characteristics evaluated. Application of 150 kg·hm^-2 level of N increased in 11%, 59%, 22%, 15%, 15% and 17% in LCI, NO₃^-, N, total amino acids (TA), SUC, and proline concentration in leaves, compared with 0 kg·hm^-2 of N, respectively. Application of 150 kg·hm^-2 level of N improved the leaf catalase activity (CAT) under the irrigation system; however, in a rainfed system, the highest CAT was observed at rates of 0 and 150 kg·hm^-2 level of N. Irrigation increased in 55%, 117%, 68%, 46%, 8%, 36%, 24%, 118%, 48%, 10%, 11% and 72% in Chl a, Chl b, total Chl, CAR, LCI, pheophytins (Pheo), SUC, NO₃^-, the number of vegetative branches, the number of reproductive branches, mass of 20 bolls and seed cotton yield compared with rainfed system, respectively, however, the antioxidant system and the ammonium content of plants was stimulated by rainfed cultivation.
Conclusions Antioxidant responses increased during droughts in cotton farming, which may be connected to oxidative stress-related losses. Better N metabolism, photosynthetic pigments, and manufacturing components were all made possible by irrigated cultivation. The delivery of 150 kg·hm^-2 of N in topdressing in cotton agriculture promoted the N metabolism, sucrose, total amino acids, and the plant’s defense mechanism against oxidative stress.

本文针对提高棉花病虫害检测效率需求，提出了一种基于YOLOv5s改进的棉花叶片病虫害检测模型YOLOv5sMBT，该模型在YOLOv5s模型基础上构建多尺度特征提取网络（Multi-scale），提升特征提取能力；在特征提取网络与颈部网络间引入Transformer注意力机制，并与C3模块结合构成C3TR，提升模型对目标的注意力；引入加权双向特征金字塔网络（BiFPN）结构高效融合特征，加强底层和深层特征融合。以4种常见棉花病虫害（盲蝽、红蜘蛛、枯黄萎病、蚜虫）的2 179张叶片图片为数据集，按照3∶1∶1比例划分为训练集、验证集和测试集，进行病虫害检测验证。结果显示，YOLOv5sMBT模型的平均检测精度（mAP）值为0.838，优于原有模型（0.799）。本文为棉花病虫害的智能检测提供参考。

全球棉花生产体系正面临日益严峻的挑战，亟需在不断增长的纤维需求与紧迫的可持续发展目标——如缓解水资源短缺、减少温室气体排放及控制农业化学污染——之间实现平衡。传统栽培模式受限于目标单一化及产量、纤维品质、劳动效率与生态影响之间的固有权衡，难以应对这些系统性挑战。基于前期提出的协同栽培概念，本文首次系统性地提出并阐述了“棉花多目标协同栽培”（MOICC，亦称为“协同栽培”）。这一变革性模式以三大支柱为核心：动态权衡管理（如基于区域特点的目标优先级动态调整）、系统技术融合（融合精量播种、合理密植、化学调控、水肥协同及高效脱叶等技术）以及资源循环利用（通过时空优化与废弃物回收实现）。MOICC通过调控关键生理机制以突破可持续性瓶颈，主要包括：乙烯信号增强的逆境成苗机制；茉莉酸介导的水分与养分协同增效途径；冠层光竞争与激素调控耦合实现的免整枝管理；以及生长调节剂驱动的集中成熟机制。基于中国新疆、长江与黄河流域多样化农业生态系统及间作体系的案例研究表明，MOICC能够实现显著的协同增益：产量提升8%-22%；资源利用效率显著改善（水分利用率提升20%以上，氮肥偏生产力可达35 kg kg⁻⊃1;）；环境表现全面提升（劳动力投入减少30–40%，碳足迹降低24–37%，化肥与农药用量分别减少15–20%与25%）。尤为关键的是，MOICC通过系统集成化优化有效化解了核心矛盾：产量与品质的冲突（依托≥70%的内围铃实现平衡）、省工与生态安全的矛盾（依靠精准脱叶时机实现二者兼顾），以及生产力与排放的权衡（通过根区氮素监测进行调控）。未来研究重点应包括：解析多尺度胁迫适应机制、开发智能决策支持系统、推进全产业链碳中和路径、破解社会经济采纳壁垒以及构建协同政策框架。MOICC为全球棉花生产提供了一条可扩展的路径，旨在协同实现高产、优质、资源高效与生态可持续的目标，不仅为产业可持续转型提供了系统性框架，也展现出向其他主要作物体系推广的潜力。

辽河流域棉区不同化学封顶技术缺乏适配参数，为明确化学封顶剂浓度与处理时间的应用效果，采用农大化学封顶剂[25%甲哌鎓(1,1-dimethyl-piperidinium chloride，DPC)+助剂环烷酸盐]于2019—2020年在辽宁省经济作物研究所（辽宁辽阳）进行比较试验，设2个处理时间（7月13、18日）和3个处理浓度(750、1125、1500 mL/hm²)，共6个处理，以不打顶为对照(CK)，连续测量植株主茎顶端(0~5 cm)和亚顶端(5~10 cm)的生长素(IAA)、脱落酸(ABA)、赤霉素(GA₃)、玉米素(ZR)的含量，并观察记录植株的生长发育（株高、果枝数、上部果枝长度、上部节间长度）情况。结果表明：（1）IAA、ABA含量变化幅度总体与处理浓度呈正比，ZR含量变化幅度总体与处理浓度呈反比，中等浓度处理(1125 mL/hm²)GA₃含量变化幅度较大。（2）不同浓度处理的IAA、ABA和ZR含量变化在7月13日处理时差异明显，GA₃含量变化在2个处理时间没有明显差异。IAA含量变化在主茎顶端比亚顶端差异明显，ZR含量在亚顶端变化幅度较大，ABA和GA₃含量变化在2个部位无明显差异。（3）化学封顶对植株发育主要表现为抑制作用，其中，果枝数和上部果枝长度随处理浓度提高受抑制程度增加，7月13日处理随处理浓度提高株高受抑制程度加强，7月18日处理株高和上部节间长度都表现中等处理浓度受抑制程度最强。研究认为，化学封顶剂处理后，主茎顶部IAA和GA₃含量明显降低，ABA含量明显提高，ZR含量变化不明显，并且IAA和ABA含量下降幅度与封顶剂浓度呈正比，处理时间越早变化幅度越大。主茎顶端IAA含量变化较明显，亚顶端ZR含量变化幅度较明显。封顶剂处理后植株发育受到抑制，总体变化与激素变化趋势一致。未来可结合产量与纤维品质指标，优化化学封顶剂施用参数，建立适配辽河流域棉区的轻简化栽培技术体系。

针对新疆盐渍土中NaCl和Na₂SO₄为主的盐胁迫制约棉花生产，且单一盐胁迫鉴定不全面的问题，为筛选稳定耐盐种质，综合评估不同材料的耐盐性。本研究以75份陆地棉种质为试验材料，采用150 mmol/L NaCl和Na₂SO₄模拟盐胁迫，测定发芽势、发芽率、下胚轴长、根长和鲜重等5个性状，结合主成分分析、隶属函数法以及聚类分析对耐盐性进行综合评价。结果表明：（1）相较于对照组，2种盐胁迫均对各项萌发指标有不同程度的抑制作用，且Na₂SO₄的抑制作用强于NaCl。（2）聚类分析显示，在欧氏距离5处2种盐胁迫下均可将供试材料划分为5个耐盐等级。NaCl盐胁迫下，高耐型6份（占比8.00%），耐盐型13份（占比17.33%），中耐型22份（占比29.33%），敏感型25份（占比33.33%），高感型9份（占比12.00%）；Na₂SO₄盐胁迫下，高耐型仅有1份（占比1.33%），耐盐型6份（占比8.00%），中耐型16份（占比21.33%），敏感型37份（占比49.33%），高感型15份（占比20.00%）。（3）2种盐胁迫条件下耐盐性表现一致的材料共有22份，其中高耐型1份，耐盐型1份。不同陆地棉种质萌发期耐盐性差异显著，‘中棉所96B’和‘新陆中73号’为2种盐胁迫下均稳定的耐盐种质。未来可结合苗期耐盐性鉴定及分子标记分析，深化耐盐机制研究，为棉花耐盐育种提供更全面支撑。

豆科作物间作可增强非共生生物固氮（BNF）作用，但其潜在机制，尤其是不同生态位宽度的土壤关键固氮菌类群在其中发挥的作用仍不明确。本研究通过田间试验，评估了花生/棉花间作与各自单作条件下根际与非根际土壤中BNF活性的变化。通过固氮速率、固氮酶活性以及nifH基因丰度，结合微生物系统发育零模型、共现网络及生态位宽度分析，探讨关键固氮类群及其生态功能与BNF的关系。结果显示，与非根际土壤相比，根际土壤的BNF潜力提高了7.8%–125.5%；与单作相比，花生/棉花间作系统中固氮速率、固氮酶活性和nifH基因丰度提升了11.6%–323.0%（P<0.05）。固氮菌群落组成与多样性存在显著差异：间作系统与根际土壤中增加了大部分变形菌门（α-变形菌外）、降低了蓝藻门和厚壁菌门的相对丰度。固氮菌的群落构建主要受确定性过程驱动，尤其是异质性选择过程，在根际（91.9%）和间作土壤（86.3%）中占主导地位。此外，间作系统与根际土壤中的固氮菌共现网络更复杂、连接性更强，其中，优势类群为机会型固氮菌（78.8%–85.9%），其次为特化型（10.2%–18.5%）和泛化型（1.38%–3.80%）。网络关键类群（机会型的Azoarcus、Azohydromonas 和Steroidobacter，泛化型的Pseudomonas 和Azotobacter），以及土壤微生物量碳和硝态氮，与间作系统和根际土壤BNF活性的增强显著相关。花生/棉花间作通过选择性招募生态功能不同的关键固氮类群，尤其是机会型固氮菌，从而提升农田BNF潜力，促进农业可持续发展。

水力理论预测叶片水力导度（K_leaf）与气孔导度（g_s）之间存在正相关关系；然而，这一理论并未得到充分的观察支持，其潜在机制仍不清楚。目前，将K_leaf细分为木质部内水力导度（K_x）和木质部外水力导度（K_ox）为阐明K_leaf对g_s的调节机制提供了新的视角。最优的种植密度可以通过优化g_s来提高水分利用效率（WUE）；然而，在这一过程中叶片水力特性的变化及其对g_s和WUE的调节机制尚不明确。我们研究了K_x和K_ox与g_s、光合速率（A_N）和WUE之间的关系，并调查了在12、18、24、36、48、60、72和84株/平方米的8种种植密度下，影响K_ox的结构基础。结果显示，随着种植密度的增加，K_leaf和A_N保持一致，而K_ox和g_s显著下降。K_ox受叶片厚度和细胞间空气空间体积分数的显著影响。K_leaf和K_x与A_N和g_s没有相关性，但K_ox与g_s表现出显著的正相关。此外，K_ox与WUE显著负相关。这些发现表明，K_ox通过调节g_s来减少水分损失，同时维持A_N，从而在不同种植密度下提高棉花的WUE。

【目的】针对新疆水资源短缺和土壤肥力较低等问题，探究加气滴灌下不同灌水量和有机无机肥不同配比对土壤质量，棉花的生长、产量和水分利用效率的影响，为确定新疆棉花节水高效可持续生产的灌溉施肥模式提供理论依据。【方法】于2023和2024年在新疆生产建设兵团146团地区开展大田试验，在加气滴灌下设置2个灌水量（W1：80%ET_C和W2：100%ET_C，ET_C为作物蒸发蒸腾量）和5个有机无机肥配施比例（OF1：100%化肥，OF2：75%化肥+25%有机肥，OF3：50%化肥+50%有机肥，OF4：25%化肥+75%有机肥，OF5：100%有机肥），研究其对土壤质量指数（SQI）和棉花叶面积指数（LAI）、干物质累积量、产量、水分利用效率（WUE）的影响。【结果】土壤质量指数（SQI）随有机肥占比的提高而增大。与单施化肥相比，有机无机肥配施处理SQI两年平均提高了9.9%—28.8%。亏缺灌溉下土壤含水量和棉花LAI、干物质累积量、产量显著下降，而WUE显著提高。在两种灌溉水平（W1和W2）下，土壤含水量和棉花LAI、干物质累积量均随有机肥占比的增加呈先升后降趋势，W1灌溉水平下W1OF3处理以上指标取得最大值，而W2灌溉水平下W2OF2处理达最大值。与单施化肥OF1相比，有机无机肥配施处理两年土壤含水量、棉花的LAI和干物质累积量分别提高了0.4%—5.2%、4.1%—19.8%和3.7%—18.8%。两年籽棉产量均以W2OF2处理最大，两年平均产量为6 739.99 kg·hm^-2，但WUE以W1OF3处理最高，两年平均为1.42 kg·m^-3。分别利用隶属函数法、TOPSIS法和灰色关联度分析法对不同处理的SQI、籽棉产量和WUE进行评价，并结合整体差异组合评价模型对棉田SQI、籽棉产量和WUE进行综合评价，确定最优处理为W1OF3。【结论】考虑节水优先，保证产量的同时提高WUE和土壤质量为目标，推荐在加气滴灌下采用80%ET_C和50%有机肥+50%化肥作为新疆棉田节水高效生产措施。

本研究旨在研究膜下滴灌灌水定额对北疆棉花生长发育、耗水特性及产量的影响，为该区域棉花生产的节水、增产、增效提供理论依据。试验于2022—2024年通过设置4种不同灌水定额：30.0 mm(I20)、37.5 mm(I25)、45.0 mm(I30)和52.5 mm(I35)，探究不同滴灌定额对棉花生长指标、耗水规律及产量的调控效应。结果表明，随灌水定额的增加，棉花株高呈增加趋势，在I30和I35处理下达到峰值；而叶面积指数(LAI)和叶绿素相对含量(SPAD)呈先升后降趋势，峰值均出现在I30处理。棉花各生育阶段耗水量及作物系数均随灌水定额的增加呈上升趋势。棉花籽棉产量和皮棉产量随灌水定额的增加呈先增加后降低的趋势，其中I30处理产量最高，平均值分别为5535.35 kg/hm²和2348.42 kg/hm²。耗水量-产量的拟合分析表明，适宜耗水量范围为491.93~571.61 mm。综合评价结果表明，I30处理在3个生长季的综合评分均最高。综上，I30处理可实现北疆滴灌棉花产量最优，研究结果可为北疆棉花节水高产栽培提供理论依据。

Background Mepiquat chloride (MC) is a widely used plant growth regulator in cotton (Gossypium hirsutum L.). It regulates endogenous hormone content and crosstalk to control plant height and promote lateral root (LR) development. However, the roles of cytokinins (CTKs) in the MC-induced increase in LR number in cotton seedlings remain unclear. Therefore, in this study, whole-genome transcriptome analysis was performed to elucidate the molecular mechanisms, CTK transformation, and CTK signaling pathway response to MC in cotton roots.
Results In the present study, MC reduced the contents of the active CTK trans-zeatin (tZ) and N⁶-isopentenyladenine (iP) but increased the levels of the nucleoside CTK trans-zeatin riboside (tZR) and N⁶-isopentenyladenine riboside (iPR). RNA-seq data showed that the CTK biosynthesis genes GhIPTs and active CTK catabolism genes GhCKXs were obviously upregulated after MC treatment. The CTK-activating enzyme gene GhLOGs was repressed compared with the control. Furthermore, MC inhibited the expression of GhAHK4 and GhARR2/12, which are involved in the CTK signaling pathway, and activated the IAA-IAA14-ARF7/19 signaling module. Meanwhile, MC increased the expression levels of genes involved in sucrose synthesis, the cell cycle, cell division, and cell wall biosynthesis pathways. Silencing the GhCKX family separately decreased the LR number and active indole-3-acetic acid (IAA) level. The expression levels of GhPIN1, GhARF7, GhARF19, GhLBD16, GhLBD18, GhLBD29, and GhLBD33 were downregulated, but GhARR2/12 and GhIAA14 were upregulated. The total content of active CTKs was noticeably increased. The results of silencing the GhLOGs family were opposite to those of silencing GhCKXs. Silencing GhARR12 could upregulate GhPIN1 expression and increase LR number. In addition, the silenced GhCKXs, GhLOGs, and GhARR12 were less responsive to MC-induced LR growth than the control.
Conclusion These results suggested that MC treatment could upregulate CTK-nucleoside biosynthesis and CTK metabolism genes to decrease active CTK levels, promoting crosstalk between CTKs and auxin signaling pathways to enhance LR initiation.

Background Achieving a synergistic enhancement in both the yield and insect resistance of Bt cotton holds substantial importance for boosting farmers' income and ecological advantages. This study investigated the impact of amino acid foliar fertilizer (AAF) on the yield and Cry1Ac protein (CP) content, providing valuable insights for enhancing its productivity and insect-resistance capabilities. In 2021, Sikang 1 and Sikang 3 were treated with AAF once (A1) and water (CK) during the peak flowering stage. In 2022, AAF was sprayed one (A1), two (A2), and three (A3) times, respectively, with CK serving as the control.
Results Compared with the control, the A3 treatment increased seed cotton yield (SCY) by 16.0% and CP by 40.98% at 30 days after flowering. AAF application enhanced soluble protein content (SP) and glutamate pyruvate transaminase (GPT) activity, while suppressing protease and peptidase activities. Concurrently, AAF improved sucrose metabolism through elevated sucrose content and increased activities of sucrose synthase (SS) and sucrose conversion enzyme (SCE), which were also positively correlated with yield. A lower ratio of carbon-to-nitrogen (C/N) was linked to higher yields and CP content. Path analysis confirmed that SP, GPT, SS, and SCE demonstrated positive effects on CP content and SCY, respectively. Peptidase activity had negative effects on CP and SCY. The C/N ratio had negative effects on SCY and CP, respectively.
Conclusions Triple foliar application of AAF maintained lower C/N ratios with enhanced carbon metabolism and protein synthesis capacity, thereby simultaneously increasing both Cry1Ac protein content and yield in Bt cotton. These findings provide critical insights for improving both pest resistance and agronomic performance in Bt cotton cultivation.

Background Cotton lodging has become increasingly prevalent due to extreme environmental conditions and agronomic practices, severely compromising yield, fiber quality, and mechanical harvesting efficiency. However, research on cotton lodging remains limited, with most studies focusing on individual or isolated indices rather than a comprehensive system. This study systematically compared four lodging-resistant varieties (LR-1, LR-2, LR-3, LR-4) and four lodging varieties (L-1, L-2, L-3, L-4) across multiple indices: morphological traits, boll distribution, internode filling degree, stem density, mechanical strength, anatomical structure, and chemical composition.
Results The results showed that at the boll-opening stage, lodging-resistant varieties exhibited higher density in the first (increased by 11.6%) and third (increased by 23.5%) basal internodes compared with lodging varieties and significantly greater filling degree in the first (increased by 22.6%), second (increased by 23.1%), and third (increased by 26.1%) basal internodes; significantly higher stem puncture strength (increased by 41.2%) and stem bending resistance (increased by 38.2%); and a significantly lower stem lodging coefficient (19.0% lower in lodging-resistant varieties). Additionally, lodging-resistant varieties showed significantly enhanced anatomical structures, including greater cortex thickness, more mechanical tissue layers, and larger pith cavity, xylem, and phloem areas. Conversely, no significant differences were observed in morphological traits, boll distribution, or chemical composition between the lodging-resistant and lodging types.
Conclusion Lodging-resistant varieties exhibited thicker cortical tissue and mechanical tissue layers, along with larger xylem area and phloem area in basal internodes. These structural characteristics provide superior support for the filling degree and density of basal internodes, thereby enhancing stem puncture strength and bending resistance, and ultimately improving lodging resistance in cotton. These findings provide a theoretical basis for reducing the occurrence of cotton lodging.

Crop chemical regulation using plant growth regulators (PGRs) represents a key strategy for achieving high-efficiency cotton production in China. This review synthesizes four decades of research on mepiquat chloride (MC), an inhibitory PGR pivotal to optimizing cotton growth architecture, stress resilience, and yield-quality parameters. We detail MC's stage-specific roles—from root development and flowering acceleration to canopy optimization and assimilate partitioning—and its mechanistic interactions with hormones (e.g., gibberellin suppression, cytokinin enhancement) under biotic/abiotic stresses. Furthermore, we conceptualize MC deployment into three evolutionary tiers: (1) symptom-guided remedial application, (2) systemic growth-stage programming, and (3) integrated management with agronomic practices. These paradigms, supported by field validation across China's cotton belts, offer a roadmap for precision regulation. Future advancements in nano-formulations, digital agriculture, and PGR synergism are discussed to unlock next-generation yield frontiers.

Background Aquaporins (AQPs) are integral membrane proteins belonging to the major intrinsic protein (MIP) family, playing a crucial role in water transport, cell elongation, and stress responses. However, their evolutionary dynamics and functional roles in Gossypium species remain poorly characterized.
Results In the present study, a total of 55, 54, 54, 103, 106, 108, and 104 AQP genes were found in G. herbaceum, G. arboreum, G. raimondii, G. barbadense, G. tomentosum, G. mustelinum, and G. darwinii, respectively. Phylogenetic analysis classified them into five conserved subfamilies (PIP, TIP, NIP, SIP, and XIP), with 95 genes showing synteny across species and 17 displaying divergence, suggesting subgenome differentiation. Transcriptome analysis revealed that specific GbAQP genes are involved in early salt stress responses and fiber development. Physiological assays demonstrated stronger salt tolerance in tetraploid cottons, particularly G. darwinii, compared with diploids. Co-expression network analysis linked AQPs to abiotic stress and fiber traits, and virus-induced gene silencing (VIGS) confirmed four AQP genes as critical for salt tolerance.
Conclusion This study provides comprehensive insights into the evolution, expression, and functional roles of AQPs in cotton, identifying key candidate genes for improving salt tolerance and fiber quality in Gossypium species.

Background Thidiazuron (TDZ) is a widely used chemical defoliant in commercial cotton production and is often combined with the herbicide Diuron to form the commercial defoliant mixture known as TDZ·Diuron (T·D, 540 g·L^-1 suspension). However, due to increasing concerns about the environmental and biological risks posed by Diuron, there is an urgent need to develop safer and more effective alternatives. Jasmonic acid (JA) and its derivatives are key phytohormones in organ senescence and abscission.
Results Greenhouse experiments at the seedling stage revealed that Me-JA (0.8 mmol·L^-1) alone did not induce defoliation. However, its co-application with TDZ (0.45 mmol·L^-1) at concentrations of 0.6, 0.8, and 1.0 mmol·L^-1 significantly enhanced defoliation efficacy. The most effective combination—TDZ with 0.8 mmol·L^-1 Me-JA—achieved a 100% defoliation rate at 5 days after treatment (DAT), 23.7 percentage points higher than TDZ alone, and comparable to the commercial TDZ·Diuron formulation with equivalent TDZ content. Field trials conducted in Beijing (Shangzhuang), Hebei (Hejian), and Xinjiang (Shihezi) confirmed that the combination of 0.6 mmol·L^-1 Me-JA with 1.70 mmol·L^-1 TDZ provided optimal defoliation performance. At 21 DAT, the defoliation rate increased by 13.5-16.3 percentage points compared with TDZ alone. Furthermore, boll opening rates improved by 5.7-12.7 percentage points relative to TDZ-only treatments. Phytohormonal analyses from the Shangzhuang site showed that the combined treatment significantly altered hormone levels in both leaves and petioles. Compared with TDZ alone, the mixture reduced concentrations of auxin (IAA), cytokinins (Z + ZR, iP + iPA, DHZ + DHZR), and gibberellic acid (GA₃), while increasing levels of JA, abscisic acid (ABA), and brassinosteroids (BR). These hormonal shifts may underlie the enhanced defoliation observed with the combined treatment. Importantly, the TDZ-Me-JA combination did not adversely affect cotton yield, yield components, or fiber quality.
Conclusion The combination of Me-JA and TDZ has a good defoliation effect without affecting crop yield or fiber quality. And it provides a promising foundation for the development of novel, environmentally friendly cotton defoliants.