Genetic Background Analysis And Heterosis Study On Jin-A Cytoplasmic Male Sterile Line In Cotton

Since Meyer bred the first Male Sterile Line with Cytoplasm of anomalum Wawr.& peyr in the world in 1960ˊs, peaple have been deeply studing Cytoplasmic Male Sterile Line in Cotton (CMS). Jin-A male sterile line is a Cytoplasmic male-sterility originated from trispecific hybrids[(G.hirsutum)×(G.thurberi Tod D1)]×[(G.arboreum)×(G.hirsutum)].The study deals with Jin-A male sterile line in cytological characters and fertilility representation, isozyme analysis, backcrossing effect, as well as utilization of hybrid vigor.The results are summarized as below: Cytological characters and fertilility test revealed, Jin-A sterile line had smaller flower, thin and small anther, and there were no pollens in the anthers. Shapes of plant of was similar to G.hirsutum. The progeny plants of Jin-A has complete sterility, and also the sterility was steady; the upland cotton varieties were could offered as the maintainer line for it, the sea island cotton varieties could restore the fertility for it. So Jin-A was new nelo-cytoplasmic sterile line with Cytoplasm of upland cotton. The study on isozyme showed, there were some responsible bands of esterase and peroxidase for all tissues. In addition, less differences in the same nutrient tissuepart between them, indicating that they had similar genetic background. Obvious differences were found due to the influence of male sterile genes.When entering reproduction stage, two isozymes of Jin-A were obvious less than that of B-line in "sporophyte-cell multiplication"period(esterase Rf=0.20, peroxidase Rf=0.18,0.20,0.33). which showed the male sterile genes controlled the synthesis of isozymes. So,the abortive pollens were informed. The resules of backcrossing indicated, though the new breeding sterile were near to their maitainers on appearance and basic characterristics, but ever existed significant differences between them, Jin-A represented basic characters such as prematurity, longer fiber, lower lint, more sterile seeds and fewer individual boll seeds. From the correlative analysis, it could been seen the magistral effect dominating each character was different. nelo-cytoplasmic effect was outstanding on lint, lintindex, index and prematurity; nucleolus′was outstanding on orderliness fiber strength, micronair value and elongate rate; Cytoplasm′was outstanding on fiber length, seed numbers and sterile rate, environment′was outstanding on boll weight and developmental period. . The results of heterosis study included, Jin-A hybrid F1 showed vigor on prematurity, lint, boll weight, lintindex than CK, the yield of (Ak4×R142)F1, ranked the first,had reached 141.7 percent of CK, and there were distinct differences between them. In addition,the correlation arrived in distinct level between lint yield and fiber strength , lint traits; significant level between lint yield and boll numbers,boll weight traits.