Genetics And Molecular Tagging Of QTLs For Yield And Fiber Quality Traits In G.hirsutum L.

Simian 3 had been one of cotton cultivars grown extensively in Yangtze River Cotton-growing Valley with high yield and high lint percentage, and one of the most excellent cotton cultivar in China bred with conventional breeding method as well as the most suitable material for studying the genetics of traits closely related to high yield. It is meaningful to study the genetic mechanism of the cultivar for high yield breeding. In the dissertation, a RIL population as well as F₂, BC₁ and BC₂ generations of Simian 3 X Carmen had been cultured to study the genetic and tagging QTLs controlling high yield of Simian 3.1, Decision of the main traits improved for breeding new cultivars with high yieldThe correlation coefficient analyses, path coefficient analyses and regression analyses had been conducted to the RIL population of Simian 3 X Carmen to decide the main traits to be improved for breeding high yield cultivars. Based on the lint yield model applied generally in China, the most important trait to be improved for breeding high yield cultivars is bolls per plant, while the second of that is lint percentage. Based on the Kerr's geometric model of yield components about lint yield, the most important trait to be improved for breeding high yield new cultivars is seeds per plant, while the second of that is lint percentage. The most important trait to be improved for getting more seeds per plant is to increase the bolls per plant. In Yangtze River Cotton-growing Valley, the most important trait to be improved for getting more bolls per plant is to increase the fruit notes per plant, while in the Yellow River Cotton-growing Valley, is to raise the ratio of boll formation. Lint percentage can be improved by increasing the lint index at lower level, but the only way to improve lint percentage is to coordinate the lint index and seed index at higher level. As a result, the main traits improved for breeding new cultivars with high yield are bolls per plant and lint percentage based on the two yield components models.2, Study on the genetic about high yield of Simian 3Jointly segregating analysis of P₁, P₂ generations and RIL population as well as P₁, P₂. F₁, B₁, B₂ and F₂ generations were used to analyze the genetics of lint yield and its related traits in (Simian3 × Carmen) by using the method of major gene plus polygene mixed inheritance model. The field trials had been taken in three environments. The optimum models of all traits are major gene plus polygene mixed inheritance models. The result indicated that the inheritances of the traits were controlled by major genes, and the expression of major gene can be varied by environmental condition as it had been proved by the fact which the genetic model of...