Research On Propagating By Cutting And Maintaining Perennially Of Genic Male Sterile Lines For Heterosis Utilization In Upland Cotton

Genic male sterile (GMS) lines of plant has the characteristic which is easy to restore but hard to maintain. The research is according to the climate characteristic of the south of Guangxi where is no frost in the winter, exploring the possibility and basis of theory of propagation by cutting and perennial cultivation of GMS lines in upland cotton in the south Guangxi, providing foundation for establishing a new technological system of F₁ hybrids production of GMS lines in upland cotton(Gossypium hirsutum L.).GMS lines of Dong A were used as material, the growing and developmental law, and the main characteristics under the situation of propagation by cutting and perennial cultivation, and probed into their value of utilization on heterosis were carried out. Acquired the following results:I . Annual cutting-propagated plants of Dong A were slightly lower thanseedling plants in the growth process of height, but there weren't any significant difference in the growth process between them; annual cutting-propagated plants were significantly better than seedling plants on stem diameter, length between nodes of main stem, boll weight and seed index; stuffy plant percentage ,stuffy section percentage, effective fruit branches and yield of annual cutting-propagated plants were significantly worse than annual seedling plants, but there were no significant difference between them on the investigated characteristics next year.II. Compared to annual seedling plants of Dong A, the yield of biennial seedling plants significantly improved, and the fiber quality didn't change significantly.III.Cutting-propagated, biennial and annual seedling GMS plants of Dong A were used as female parents, two cultivars of upland cotton and one cultivar of island cotton were used as male parents, compounded 9 hybrid combinations. The multiple comparisons showed that: under the different male parent, there was significant difference among performance of hybrid heterosis, the hybrid of island cotton and upland cotton displayed very strong superiority in output, quality, resistance, etc.; under the same male parent, there was no significant difference among hybrids of different propagated ways and cultivated ages of female parents. The result implied that heterosis of descendants had the relation with the genetic composition of their parents, and had no relation with the propagated ways and cultivated ages of their parents.As a consequence, it is feasible to utilize cutting-propagated plants of GMS lines Dong A as female parents, but await to further optimization on the selection of cutting and the management of cultivating cutting-propagated plants; maintaining characteristic of GMS perennially had a good utilizing prospect, but should assure its overwintering survival rate.The management and working life of GMS lines were two important problems which should be researched forward.