| Cotton is not only a cardinal cash crop, but also an important raw material for textile industry. With the economy internationalized and the world commercial market blended the cotton fiber quality cannot meet the damand of the textile industry and instrument innovation. With the improment of living standard and the development of textile industry it is urgent to improve the fiber quality.Fiber quality can be improved by the traditional breeding methods including crossing, back crossing and intercrossing and so on. However it is too expensive, time consuming and low efficency in selection.With the development of the molecular marker, the molecular marker assisted selection to improve the fiber qualities are present. It is possible to identify the cotton with good fiber quality at seedling stage with one or a few molecular markers tightly linked to major genes controlling the important fiber properties, which will help to improve the fiber quality and yield of cotton variety rapidly, prominently and efficiently. Inheritance and molecular tagging of super fiber properties in cotton were conducted in the present paper.Using the molecular marker SSR as technology support, constructing the Fa progeny population from a cross of two land cottons, QTL analysis is carried out. The goal of this research is to find some genetic loci which are related to the yield and quality traits, and these loci will serve as the basis of molecular genetic improving. The main study results are listed as follows:1. Constructing FI population including 188 individual from two upland parents. The data of boll weight, boll number, lint percentage were achieved, the fiber sample were tested with HVI test system.the results including fiber length fiber strength, fiber unitormity and fiber elongation.2. The fiber traits about cotton yield and quality were observed and the normal distribution test for these traits segregated in p2 was performed. Accordingly, the frequency charts of each trait were made out. From these charts, we can see that boll number, lint percentage, fiber unitormity and fiber elongation appeared exceptional distribution.3. The correlation analysis of the fiber traits indicated that fiber strength, fiber unitormity and lint percentage were high significantly correlated with fiber length, which indicated that it was easier to select the fiber length and fiber strength simultaneously. While micronaire was high significantly negative correlation with fiber elongation. Lint percentage was high significantly negative correlation with fiber length which indicated that there still existed severely undesirable negative correlation between yield and fiber properties as well as the difficulties for their simultaneous improvements.4. Bulked segregation analysis was employed to produce 6 pairs of mixed DNA pools including lint percentage, fiber length, fiber strength ,micronaire, fiber unitormityand fiber elongation according to individual value of F2, and a total of 386 couple cotton SSR primers are screened between the parents, only 26 couple SSR primers that appear different between parents . Polymorphism proportion amounts to 6.7%. Five markers were identified to be linked with fiber trait throuth DNA polymorphism surveying between the parents, and the paired bulked, and screening the individual plant of F2.5. Linkage test indicateds five markers could be mapped to two linkage groups. The first linkage group concludes three markers M187-M5-M365, the distance is 37.8cM, 41.1cM respectively. The second linkage group concludes two markers Mill and M683, the distance is 30.3 cM.6. Using interval mapping methods, the QTLs of fiber quality in (Zhongl6 X G97038) F2 were tagged and mapped with 5 SSR closely linked to boll weight, boll number, lint percentage and fiber strength. 6 major QTLs relevant to yield and quality were found. Among the five markers, two linked for boll weight, one closely linked to M5 (with the distance l.8Cm), the other linked to Mill (l0cM), could explain 39.4% and 39.31% of... |
PDF Full Text Request