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With 3 figures As one of the genic male sterility (GMS) materials in chili pepper ( Capsicum annuum L.), GMS1 has been used for commercial F1 hybrid seed production. The male sterility of GMS1 is controlled by a recessive nuclear gene, named ms 1. In this study, we developed DNA markers linked to the ms 1 locus using a combination of bulked segregant analysis and amplified fragment length polymorphism (AFLP) in a segregating sibling population. From the screening of 1024 AFLP primer combinations, the AFLP marker E-AGC/M-GTG (514 bp) was identified as being linked to the ms 1 locus at a distance of about 3 cM. Based on internal sequencing analysis of the E-AGC/M-GTG marker between male fertile and sterile plants, we identified three small deletions with a size of altogether 42 bp in the male-fertile plant and developed a codominant sequence characterized amplified region (SCAR) marker. This SCAR marker may be valuable for marker-assisted breeding in the hybrid seed production system of chili pepper using the GMS1 line. [ABSTRACT FROM AUTHOR]

Two genic male sterile (GMS) lines, Lang-A conditioned by ms 15 and Zhongkang-A conditioned by ms 5 ms 6 duplicate recessive genes in Gossypium hirsutum L., were chosen to map GMS genes. These two lines were crossed with Gossypium barbadense cv. ‘Hai7124’ to produce segregating populations. The ms 15 gene was mapped on chromosome 12, and was flanked by two simple sequence repeat (SSR) markers, NAU2176 and NAU1278, with a genetic distance of 0.8 and 1.9 cM respectively. The ms 5 and ms 6 genes were mapped to one pair of homoeologous chromosomes, ms 5 on chromosome 12 flanked by three SSR markers, NAU3561, NAU2176 and NAU2096, with genetic distances of 1.4, 1.8 and 1.8 cM, respectively, and ms 6 on chromosome 26 flanked by two SSR markers, BNL1227 and NAU460, with a genetic distance of 1.4 and 1.7 cM respectively. These tightly linked markers with the ms 15, ms 5 and ms 6 genes can be used in the marker-assisted selection among segregating populations in a breeding programme, and provide the foundation for gene isolation by map-based cloning for these three genes. [ABSTRACT FROM AUTHOR]

Rs1046AB is a dominant genic male sterility (DGMS) line in rapeseed, in which the sterility has always been thought to be conditioned by the interaction of a male sterility gene ( Ms) and its non-allelic restorer gene ( Rf). This system provides not only a tool for assisting in recurrent selection but also a promising system for hybrid production. Based on previous studies, two amplified fragment length polymorphism markers linked with the Ms gene were converted into a dominant and a co-dominant sequence characterized amplified region (SCAR) marker, respectively. The putative linear order relationship of three dominant SCAR markers with the same genetic distance from the Rf gene, was also determined by an examination of whether the homologues of these markers are present or not in different lines carrying Rf. A bigger fragment generated by the closest marker linked to the Rf gene was observed in all lines carrying the recessive allele rf, suggesting that this marker is a co-dominant marker, which was further confirmed by nucleotide sequence comparison of these fragments. SCAR markers specific for Ms and Rf will be especially valuable in marker-assisted DGMS three-line breeding. [ABSTRACT FROM AUTHOR]

The possible applications of genic male sterility (GMS) in plant breeding are reviewed and discussed. The basic contribution of GMS is that it provides a means of genetic emasculation which can be applied for the massive production of hybrids. There are two main fields of application: (1) the production of hybrid varieties and (2) inter- and intraspecific hybridization and back-crossing programmes for the introduction of genetic variation into crop varieties. Several schemes have been proposed for using GMS in hybrid breeding in different crops. These are discussed under four headings: genetic methods, cytogenetic methods, temporary restoration of fertility and manual pollination. The application of GMS in hybridization intended for the introduction of alien genes is discussed as well as factors affecting the pollination of genic male steriles. [ABSTRACT FROM AUTHOR]