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Abstract
The inheritance of male sterility was studied in germplasm of common bean (Phaseolus vulgaris L.) obtained from the Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia. The source was selected for plants with high pollen abortion rates (mean = 91%) and for failure to set any seed or pods by self-pollination when grown in screened greenhouses. These male-sterile plants were crossed with the snap bean ‘Sprite’, and the resulting F1 progenies were all male-sterile under greenhouse conditions. The F1 plants were backcrossed to ‘Sprite’ and the BC1 progenies did not segregate for male-fertile plants under field conditions. Four more backcrosses to ‘Sprite’ have produced progenies that were uniformly male-sterile. It was concluded that the CIAT source of male sterility is inherited through the maternal parent and is cytoplasmic. Nineteen commercial cultivars of snap beans and dry beans were crossed onto BC3 plants, and none of these genotypes restored the pollen fertility in F1 progeny.
The inheritance of multiple flowers and leaf pubescence resulting from the crosses between accessions from pepper species Capsicum annuum L. and C. chinense Jacq. was examined. Hand cross- and self-pollinations were made in a glass greenhouse. Only eight normal F1 plants were obtained from crosses between the two species when C. annuum L. was the female parent. F2 and backcross generations obtained from the F, and the two parents were grown in the field. Two field studies indicated that multiple flowers and leaf pubescence were controlled by dominant genes. A three-gene model leading to an F2 segregation ratio of 45:9:10 and a two-gene model leading to an F2 segregation ratio of 13:3 were suggested for the inheritance of multiple flowers and leaf pubescence, respectively. Epistasis was evoked in the interpretation of the data. No linkage was found between the two characters. The inconsistencies between F2 and backcross data might be due to selective elimination of genes from one or the other parent in an Interspecific hybridization. Segregation ratios from intraspecific crosses for leaf pubescence supported a two-gene model and gave an F2 ratio of 13 pubescent leaf : 3 glabrous leaf progeny.