Heterosis Of Cotton With Nuclear Male Sterile Lines

Three nucleic male sterility and six conventional high-yielding samples were selected as parents to make eighteen hybridized combinations, according to the NCII genetic design. Compared with Ezamian10th, hybridized combinations were randomly tested to survey agronomic traits and quality traits of each sample, assessed growth traits and physical signs of seeding stage and estimate the genetic distance between parents by SSR molecular marker-assisted breeding technology. Hybrid cotton’s superiority and combining ability effect and variance, the correlation between seeding growing-up feature and field performance and the prediction of heterosis from parents’genetic distance were analyzed by EXCEL2003and DPS which processed the data. Analysis results were listed as follows.1. Samples’heterosis performance. Samples were of diversity in lint yield, boll weight and lint percent. Compared with the reference sample, most combinations present the reduction of lint yield while some combinations present the increase which did not reach the significant level. Most combinations were highly positive dominant in boll weight and negative dominant in lint percentage. Combinations of172A×Shakang、83662A×Wanmian10th83662A×Ezamian13th、83662A×Jin173、83671A×Shakang and83662A×B11exceed the reference sample in lint yield. Samples were highly different in fiber length and micronaire. They were highly negative dominant in which the micronaires were better than the reference sample’s. From the heterosis performance in quality traits, it can be concluded that172A×Jin I5、172A×Jin173and172A×B11perform well.2. Samples’ and parents’combining ability. In female parents, genie male sterile line83662A performed well in the general combining ability of yield and quality traits which can be selected to combine the natural sterility materials. In male parents, Jin173and Jin I5performance well in the CGA of yield traits while performance generally in quality traits. The samples with good CGA do not present any special heterosis. The combination of83662A x Ekangmian13th performed the best in the specific combining ability of yield. All the samples generally performed which can be improved by the choice of better parent materials in quality trait. The specific combining ability’s traits of boll number, uniformity, elongation and fiber strength were highly related to the heterosis.3. Samples’ performance in seedling stage. There was a competitive advantage between samples’ germination rate, fresh weight and dry weight in seedling stage. Samples’ germination rate and lint yield had significant and positive influences while growth trait and field production did not have any positive influences during seedling stage. In the correlation analysis of samples’ performance and specific combining ability during seedling stage, there was certain significantly negative correlation between SPAD value and boll number and significantly negative correlation between Micronaire value and seedling length.4. Correlation between performance in seedling stage and genetic distance. Based on the analysis of parents’ results which were estimated by SSR molecular marker-assisted breeding technology, it showed that nine samples’ genetic distance was great which can be divided into four categories. There was not a significantly correlation between parents’ genetic distance and specific combining ability, heterosis and performance in seedling stage. Heterosis cannot be reliably predicted by genetic distance.