| The modem textile industry depends on the improvement of fiber quality, especially strength for meeting the needs of higher spinning speed. Greater advance in the * improvement of the fiber qualities has been achieved by the traditional breeding methods, which include crossing, backcrossing and intercrossing, etc. However, it was too expensive, time consuming and low efficiency in selection. Advances in the use of DNA markers for marker-assisted selection (MAS) are promising for streamlining plant breeding programs. It is possible to identify the excellent fiber quality plants at seedling stage with the one or a few molecular markers tightly linked to major genes controlled the important fiber qualities, which will help to improve the fiber qualities of cotton variety rapidly, prominently and efficiently in China. Inheritance and molecular tagging of super fiber quality in Upland cotton were conducted in the present paper. 1. Diallel cross analysis Twenty crosses were made among 5 varieties or lines with complete diallel mating design, which included 7235 (30.80 cN/Tex ) * I-1S427-l() (28.O醕N/Tex). PD6992 (27.10 cN/Tex)~ MD5lne (22.24 cN/Tex) and TM-I (22.46 cN/Tex).The parents and hybrids were planted in 3 replications with randomized plots in 1998 and 1999 in Nanjing, respectively. The fiber samples were tested with IIVI test 4 system in Cotton Research Institute of CAAS at Anyang. Genetic analysis of fiber quality characters were conducted by Zhu抯(1997) genetic model, ADM(additive-dominance- maternal) and AD(additive-dominance) with MINQUE(l) approach. The results indicated the fiber quality characters were mainly controlled by the additive genetic effects without maternal effects. The fiber strength and fiber length had high additive heredity, 77.6% and 73.2%, respectively, while micronaire had 45.2% for the additive and 11.5% for the dominant, which was the highest in fiber quality characters. 2. Major gene and polygene analysis . The results of joint analyses of multiple generations of P1 P2 F1 BC1 . BC2 and F2 of the crosses 7235xTM I ,TMI x7235,HS42xTM I ,PD69xTM I ,MD5 1 xTM 1 ,7235xHS42, 7235x PD69 and HS42x PD69, F2~ 3 family was also included in 7235xTM1, showed one major gene plus polygene mixed inheritance model in all fiber quality characters. The heritability of major gene varied with crosses and characters. There were higher heritability for fiber strength, micronaire, fiber length(7l .8%-8O.3%) than fiber length uniformity and fiber elongation(56.10/o--56.2%), which showed the similar results to the diallel cross analysis. The highxlow hybrid showed higher heritability than the highxhigh and the lowxlow in BC.. BC2 and F2. Most of hybrids were demonstrated higher heritability for major gene in ? F2. 3than F2, and the least in backcross generations. 3. Molecular tagging of major QTLs of fiber quality characters Bulked segregation analysis was employed to produce 3 pairs of mixed DNA poois for fiber strength, micronaire and fiber length according to individual value of 7235xTM1 F2 and F2~1. A total of 221 pairs of SSR primers, 1840 arbitrary 10-mer oligonucleotide primers and 77 ISSR primers were used to screen polymorphism between two parents, and 3 pairs of bulked DNA pools. Fifteen markers amplified thirteen...
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