Analysis Of Genetic And Molecular Markers Of Fertility Restoration Major Gene Of Cytoplasmic Male Sterility In Pepper (Capsicum Annuum L.)

Pepper(Capsicum annuum L.) is a very important vegetable crop. Because of its obvious heterosis, pepper hybrid has been widely used in production. The hybrid seed production in China now is labor-intensive and relies on manual removal of male flowers and manual pollination. The CMS trait can be used in large-scale production of hybrid seeds, which can lower labor costs, increase the genetic purity of F1 seeds and additionally protect the intelligent property of new varieties. But development of the fertility restoring lines has been a problem in pepper breeding by using CMS. If tightly Rf-linked marker were found, genome walking can be used for gene cloning and transgene technology can be used for developing fertility restoring lines. In this dissertation, genetic properties, markers screening and maker development by genome comparison were studied.1. The segregant population 77013A×(Yolo Wonder×Perennial) was genetically analyzed. Fertility restoration is controlled by more than one gene. At least one dominant Rf gene controlled fertility restoration and the CMS is affected by environment.2. One SCAR maker,5 CAPS makers,417 pairs of SSR primers,495 pairs of SRAP primers and 448 pairs of AFLP makers were screened. The SCAR maker SCAR-CRF was linked with the Rf gene. The segregant population was selected by the SCAR marker SCAR-CRF. There were 1419 plants can amplify the band (about 500bp) which linked to Rf gene,1443plants can't.χ2 value (=0.236, P=0.627) showed that fertility restoration was controlled by one major dominant gene, and genetic distance was 4.3cM.3. 35pepper lines were used to test marker applicability. The result shows that molecular result and phenotype score are consistent.4. Rf genes which have been cloned were compared with ESTs of pepper and 6 ESTs that have high levels of homology to the Rf genes were obtained from the pepper EST database.43 pairs of primers were designed and screened.Rf genes which have been cloned were compared with tomato genome and high levels of homology regions were found. Markers of tomato in these regions were screened.The polymorphic SCAR fragment was isolated and sequenced. The fragment was 556bp. Compared with tomato genome, about 100bp were homology to the T6 chromosome of tomato and had a similarity of 86%. The relationship between the homology region and the Rf gene needs more research.