Construction Of Genetic Map By SSR Marker And Location QTL For Plant Height And Heading Time In Wheat

To research the genetic basis of quantitative traits and molecular function of heterosis in wheat, apopulation of 188 recombination inbred lines (RILs) derived by single seed descent from the cross of thecommon wheat variety (Triticum aestivum L.) 3338 and the spelt wheat variety (Triticum spelta L.) Altgold,was established and frequency distribution of 8 agronomic traits were determined. The results showed thatthis population can be considered to be an ideal material for further constructing genetic map and QTLmapping.The resulting genetic map comprises 231 loci and 4137.8 cM with 1655.4 cM for the A genome,1161.9 cM for the B genome and 1320.5 cM for the D genome. 24.2% of the loci showed a significant(P<0.05) deviation from a 1:1 ratio. Most of them were in favour of Altgold.QTL for heading time and plant height were mapped via Composition interval mapping. And presenceof a QTL was declared at a significant threshold a=0.005. For each trait, between 4 and 10 additive QTLswas identified with individual contribution ranging between 1.195% and 20.77% of the total phenotypicvariation. For heading time, one QTL was located on chromosome 2D between the locus xgwm261 andxgwm349, explained 20.77% of the phenotypic variation. Another QTL located on chromosome 7Bbetween the loci Xcau156 and xgwm297 also had a strong additive effect contribution (6.40%). For plantheight, one QTL was located on chromosome 4B between locus xgwm251 andxgwm375, and explained20.77% of the total phenotypic variation. Another QTL for plant height was located on chromosome 2Dexplained 6.40% of the total phenotypic variation.Conditional analysis on growth trait showed that plant height were regulated by different QTLs indifferent phage, in early phage (before 21,April), two QTLs were identified, and located on chromosome4A and 4B, can explained 26.97% and 10.10% of the total phenotypic variation respectively. After 21,April, two QTLs was indentified on chromosome 4A (4-11, may) and 2D (18-25, may) in different phage,and explained 13.53% and 9.23% of phenotypic variation respectively.