Genetic male sterility was found in the Bell type pepper variety ‘All Big’. Breeding experiments suggest that the character is controlled by a single recessive gene in Bell type pepper varieties. This new source of male sterility appears to be superior to sources formerly reported by being highly stable and already present with a Bell type genetic background, and by the absence of undesirable pleiotropic effects. The usefulness of the character for hybrid seed production is discussed.

A stable, male-sterile, recessive mutant designated ms-2 has been isolated from ‘California Wonder’ pepper and appears useful for hybrid production of Bell pepper types.

The nuclear male sterility gene ms8 is expected to facilitate the production of sweet pepper (Capsicum annuum L.) hybrids as it provides means for hybridization without the labor-intensive hand emasculation of female inbred lines. The development of molecular markers linked to ms8 locus will help the breeding practice for the selection of hybrid parental lines. In this study, F2 population resulting from a cross between the sweet pepper male sterile line 320 and the male fertile variety Elf was used to identify DNA markers linked to the ms8 locus. With the use of RAPD–BSA technique, seven markers linked to the ms8 locus were found. Four of them were converted into SCAR markers. In addition, two COSII/CAPS markers linked to the ms8 locus were identified. Comparative mapping with reference pepper maps indicated that the ms8 locus is located on the lower arm of the pepper chromosome P4. Identified markers are useful for molecular breeding, however, at present markers tightly linked to ms8 locus are still lacking. Identification of molecular markers linked to the ms8 locus and determination of its chromosomal localization are useful for fine mapping and also provide the perspective for ms8 gene cloning.

以甜椒隐性细胞核雄性不育两用系AB91为材料,采用混合集群分析法(BSA)构建了不育池与可育池。利用SRAP分子标记技术,筛选了225对SRAP引物组合及1 393对EcoRⅠ和MseⅠ引物组合,获得了与隐性核不育基因连锁的2个SRAP标记:E37M39、E44M93,片段长度约为200 bp和500 bp,与育性基因的遗传距离为6 cm和12 cm。

A cytoplasmic male sterility (CMS) system is one of the most efficient ways to produce F1 hybrid seeds in pepper (Capsicum annuum). Restorer-of-fertility (Rf) genes are a critical component within the CMS/Rf system. The inheritance of Rf genes in pepper by joint segregation analysis was examined. The inheritance of Rf genes in the two progenies was controlled by two major additive-dominant epistatic genes and additive-dominant epistasis polygene. The two major genes had high additive effects and dominant effects. In addition, there existed significant epistatic effects between the two major genes. The major genes had high heritability in F2, BC1, and BC2 generations. Also, the fertility restorer characteristic can be selected during early generations of the breeding cycle.

Fertility restoration of Peterson's cytoplasmic male-sterility in pepper (Capsicum annuum L.) is quantitative and environment-dependent. QTL analysis of fertility restoration was performed based on the test-cross progeny of 77013A (a strict cytoplasmic-genetic male sterile line) and a doubled haploid population of 114 lines obtained from an F1 hybrid between Yolo wonder (a sterility maintainer line) and Perennial (a fertility-restorer line). The fertility of the test-crossed lines was assessed under greenhouse and open field conditions using three criteria related to pollen or seed production. One major QTL for fertility restoration was mapped to chromosome P6. It was significant in all the environments and for all the traits, accounting for 20-69% of the phenotypic variation, depending on the trait. Four additional minor QTLs were also detected on chromosomes P5, P2, and linkage groups PY3 and PY1, accounting for 7-17% of the phenotypic variation. Most of the alleles increasing fertility originated from the restorer parent, except for two alleles at minor QTLs. Phenotypic analysis and genetic dissection indicated that breeding pepper for complete sterility of female lines and high hybrid fertility requires complex combinations of alleles from both parents and a strict control of the environment.

三系配套是辣椒育种的主要研究方向，鉴定并开发辣椒恢复基因连锁标记是利用分子标记辅助选育恢复系的难点。本研究以自主选育的辣椒胞质雄性不育系014A和恢复系014C为亲本构建F₂分离群体，经χ²测验可育与不育的分离比例符合3∶1，表明辣椒胞质雄性不育育性恢复性状受1对显性基因控制。采用BSA法构建可育和不育极端DNA混池，全基因组重测序并与参考基因组比对，通过SNP-index法和Fisher检验将辣椒胞质雄性不育恢复基因定位于辣椒第6号染色体顶端1.44~8.28 Mb的区域内。根据亲本间SNP/InDel差异设计引物，在亲本和极端池筛选多态性引物，得到能稳定扩增出特异条带的分子标记PP5和OP59。这2个标记在极端群体验证中准确率均达到100%；标记OP59是共显性标记，位于恢复基因的候选基因T459-15819间区17 232 bp，该标记在不育群体准确率为100%，在可育群体准确率为97.21%；标记PP5位于恢复基因的候选基因T459-15819下游318 bp，该标记在不育群体和纯合可育群体准确率均为100%，不能区分杂合可育类型。该研究获得与恢复基因紧密连锁2个标记为加速选育辣椒CMS恢复系奠定基础。

There are many agronomic traits of pepper (Capsicum L.) with abundant phenotypes that can benefit pepper growth. Using specific-locus amplified fragment sequencing (SLAF-seq), a genome-wide association study (GWAS) of 36 agronomic traits was carried out for 287 representative pepper accessions. To ensure the accuracy and reliability of the GWAS results, we analyzed the genetic diversity, distribution of labels (SLAF tags and single nucleotide polymorphisms (SNPs)) and population differentiation and determined the optimal statistical model. In our study, 1487 SNPs were highly significantly associated with 26 agronomic traits, and 2126 candidate genes were detected in the 100-kb region up- and down-stream near these SNPs. Furthermore, 13 major association peaks were identified for 11 key agronomic traits. Then we examined the correlations among the 36 agronomic traits and analyzed SNP distribution and found 37 SNP polymerization regions (total size: 264.69 Mbp) that could be selected areas in pepper breeding. We found that the stronger the correlation between the two traits, the greater the possibility of them being in more than one polymerization region, suggesting that they may be linked or that one pleiotropic gene controls them. These results provide a theoretical foundation for future multi-trait pyramid breeding of pepper. Finally, we found that the GWAS signals were highly consistent with those from the nuclear restorer-of-fertility (Rf) gene for cytoplasmic male sterility (CMS), verifying their reliability. We further identified Capana06g002967 and Capana06g002969 as Rf candidate genes by functional annotation and expression analysis, which provided a reference for the study of cytoplasmic male sterility in Capsicum.