| Xinjiang is one of the main production base of upland cotton with high quality.The yield and total output has been the first place in the China.The advantage of the cotton industry has become the region characteristic of leading industry and the main economic source of farmers’ income.To carry out the selection of high quality cotton is an important technical support for the sustainable development about cotton industry in xinjiang. This research crossed the sea-land introgressive system 13-1 with the liao 12 cotton and builded the F2 group composed of 195 individuals and derived F2:3 family. SSR markers was used to construct the cotton genetic linkage map.Icimapping positioning software was used for QTL mapping on chlorophyll content of flocculant, fluorescence parameters,leaf dry matter, leaf area index and fiber quality traits.That can be used to analyze the photosynthetic efficiency, fiber quality and its related QTL genetic effect of the sea land introgressive 13-1.This study can provide theoretical basis for high photosynthetic efficiency breeding of the sea-land introgressive as well ae the improvement of the fiber quality.1. F2 materials derived from a cross between introgression lines 13-1×liao 12 were used as mapping population in cotton. Among the 84 polymorphic markers analyzed, 19 markers(25.3%) showed the genetic distortion(P<0.05) in the F2 population. Among these segregation distortion SSR markers, 8 SSR marker alleles were distorted to the male parent liao12(42.1%), 10 SSR markers allels were distorted to the female parent 13-1(52.61%), and 1 SSR marker alleles were distorted to the heterozygote(5.27%). These segregation distortion SSR markers were in cluster of tightly loci or single marker, which distributed in 7 different chromosomes with hot region in 1 of them. In this paper, reasons for segregation distortion and effects of segregation distortion on genetic mapping and QTL analysis were discussed.2. In this study, a genetic linkage map was constructed by the 195 F2 population derived from the cross between the parents of Introgression Lines13-1 and liao 12 with SSR markers using JoinMap 3.0 software.The map included 39 SSR loci and 13 linkage groups, covering 1174.4 cM and accounting for 26.7% of the cotton genome.3. Based on inclusive composite interval mapping method with IciMapping,37 QTLs related fiber quality were identified among 10 chromosomes inF2 and F2:3 population, including 2 QTLs for fiber elongation,9 for fiber length uniformity,19 for fiber micronaire and 7 for fiber upper half mean length. There are 19 favorable alleles originated from Introgression Lines13-1 and 18 favorable alleles originated from liao 12.Two stable QTLs could be the candidate alleles for gene function research to reveal the molecular regulation mechanism as well as for MAS breeding projects.4. Based on inclusive composite interval mapping method with IciMapping,44 QTLs were identified among 8 chromosomes in F2:3 population, including 30 QTLs for chlorophyll fluorescence parameters,7 for leaf dry material content,6 for leaf area index,and 1 for chlorophyll content. Multiple trait QTLs were located between the common range of markers on the same chromosome and the additive effect of some ones were inherited from the same parent.Some QTLs related to dry material content and maximal photochemical efficiency of PSⅡ appeared repeatedly on the different ranges of 3 chromosomes and ones associated with leaf area index and maximal photochemical efficiency of PSⅡ recurred among the different range of 4 chromosomes. These findings showing the pleiotropism or genetic linkage can be used to combine many highphotosynthesis-efficiency genes into plants by genetic engineering. |
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