Study On Restoring Gene In Pepper Cytoplasmic Male Sterile Line By AFLP Molecular Marker And Genetic Effective Of Fruit Content

Strong heterosis exists in pepper (Capsicum annuum L.) and the hybrids are nowmainly produced by "three-lines" method with cytoplasmic male sterility (CMS). Themechanism of CMS is less known in pepper than in other crops, such as rice andmaize. In the present study, genetic analysis of fertility and screening of molecularmarker tagging restoring gene were performed using a pepper three-lines, thecytoplasmic male sterile line 9704A, maintainer line 9704B and restoring line T01-65,which were selected by Hunan Vegetable Research Institute. In other experiments, theinheritance of fruit contents was also tested with two cytoplasmic male sterile lines9704A and 8124A, two corresponding maintainer lines, 9704B and 8214B, andrestoring lines, 8001 and 9701, and 8 crosses of the two restoring ones with the twocytoplsmic male sterile ones and the two maintainer ones, respectively.1. The fertility restoration of CMS was controlled by one pair of dominantgenes in F₁ and F₂ population crossed sweet pepper CMS line 9704A with restoringline T01-65.2. Bulked segregation analysis (BSA) was employed to produce two mixedDNA pools for sterility and fertility, respectively, according to the fertility of F₂population crossed by pepper CMS line 9704A with restoring line T01-65. A total of24 primers of Amplication Fragment Length Polymorphism (AFLP) were used toscreen polymorphism between CMS line 9704A and restoring line T01-65, and thetwo bulked DNA pools and the polymorphism was detected between the parents with22 primers. One marker OPL09_-170 amplified with primer M-ACA×E-CAT wasidentified to be linked stably with restoring gene.3. The fruit dissociated protein and vitamin C content in pepper CMS lines9704A and 8214A was significantly lower than that of the corresponding maintainerlines. The fruit cellulose and soluble sugar in 9704A was also significantly lower thanthat of the maintainer line 9704B. However, there was no statistically differentbetween the CMS lines and maintainer lines in fruit dry matter content. 4. The fruit contents varied in hybrids of CMS lines crossed with restoring linesand hybrids of maintainer lines crossed the restoring lines. However the difference isnot co-ordinate in difference hybrids of CMS lines crossed with the restoring lines.The sterility of CMS lines had no direct effect on the difference of fruit contents inhybrids and the fruit contents in restoring line was positively correlated with the onesin hybrid.