QTL Mapping For Important Traits Of Flag Leaf In Barley

Barley(Hordeum vulgare L.) is one of the important cereal crops, belonging to Gramineae, Triticeae, Hordeum. Barley grain production is closely related to the physiological and morphological traits of flag leaves. The research of genetic characteristics and mapping of quantitative trait locus(QTL) in these traits can provides basic information for the gene cloning and molecular breeding. In this study, SSR framework genetic map and SNP + SSR high-density genetic integrated map were constructed in our project group by using DH population from a cross between barley "Huaai 11" and "Huadamai 6", 7 physiological traits(Net photosynthetic rate, Pn; Stomatal conductance, Gs; Intercellular CO2 concentration, Ci; Transpiration rate, Tr; Relative water content, RWC; Relative chlorophyll content, SPD; Leaf nitrogen concentration LNC) and 3 morphological traits(Flag leaf area, LA; Flag leaf length, FLL; Flag leaf width, FLW) of flag leaves were analyses for QTL mapping in the DH population. The results are as follows:1. The 7 physiological and 3 morphological traits of flag leaves were measured in the barley DH population for consecutive two years, the statistical analysis showed that all traits exist significant differences between two parents(P < 0.05), the values of skewness and kurtosis were between-1 and +1, and they were normal distribution in the DH population. The coefficient of variation was 5.22%- 30.91% and 11.5%- 28.5% in 2012 and 2013, respectively. The analysis of variance showed that genotype variance of all traits were highly significant differences(P <0.01).2. A total of 38 QTL for 7 physiological and 3 morphological traits were detected using composite interval mapping method based on SSR framework genetic map. 18 QTL were detected in 2012, and accounted for 7.14%- 24.58% phenotypic variation. 15 QTL were detected in 2013, and accounted for 6.53%- 25.36% phenotypic variation. 5 QTL based on mean value of each trait were detected for LA, FLL and FLW, and explained 14.23%- 31.29% phenotypic variation.3. A total of 70 QTL for 7 physiological and 3 morphological traits were detected using composite interval mapping method based on SNP + SSR high-density genetic integrated map. 31 QTL were detected in 2012, and accounted for 4.08%- 35.52% phenotypic variation. 26 QTL were detected in 2013, and accounted for 4.4%- 30.22% phenotypic variation. 13 QTL based on mean value of each trait were detected for LA, FLL and FLW, and explained 3.06%- 36.46% phenotypic variation.This study has important significance for marker assisted selection breeding, the further research of physiological and morphological traits associated with grain production in barley.