Evaluation Of Waterlogging Tolerance And Genetic Analysis In Barley Double Haploid Population

Waterlogging can be a frequent natural calamity for drought crop productions. Barley(Hordeum vulgare L.) is relatively sensitive to waterlogging, so the stress will be one of the important limiting factors to barley productions in some areas.Development of tolerant cultivars is the most cost efficient and environmentally safe way to overcome this problem. The objective of this study was to investigate suitable selection criteria for waterlogging tolerance in barley.165 DH lines derived from a barley cross(Yerong×Franklin) were analysed using principal component analysis, dynamic clustering and subordinate function based on the specimen correlation matrix of these traits, including plant morphological and physiological traits and plant height (PH), spike length (SL), the top 1st internode length (TFIL), spike per plant (SPP), grains per spike (GPS), grain weight per plant (GWPP), grains per plant (GPP), straw weight per plant (SWPP), weight of 1000 grains (WTG), number of green leaf (NGL) and Chlorophyll content (Chl1-2). The heritability, the number of segregating gene of the waterlogging tolerance indexes of these quantitative traits were investigated based on a doubled haploid (DH) population. Meanwhile the types of gene interaction were analyzed by estimation for coefficients of skewness (g1) and kortosis (g2) of the traits. The results were summarized as follows:(1) The influence of the waterlogging on barley individual plant traits was relevant to growth stage,it had big influence on the growth of young sprout and tiller on seedling period waterlogging, but because of the early treatment, the plant physiological traits of barley had already returned to normal.It had no obvious influence on the differentiation of the barley young spike;but waterlogging brought influence on the nutrition growth at elongating stage and the differentiation of young spike. So it was proved that waterlogging at elongation stage has more sensitive than at seedling.(2) The waterlogging tolerance indexes of each trait in the two years were analysed by principal component analysis, the results were shown that three principal components and their functional equations were brought forward, and the sum of the contribute rate of the former three compositive indexes were 88.2% and 89.7%.(3) The waterlogging tolerance indexes of each trait in the two years were analysed by the comprehensive evaluation and dynamic clustering respective based on the principal component analysis, the both results of the subordinate function based on comprehensive index and dynamic clustering were approximately identical, the identical degree reached 90 percent in the two years. It was shown that it was a successful attempt for evaluating barley waterlogging tolerance using comprehensive evaluation that combinated principal component analysis, subordinate function with dynamic clustering. And the waterlogging tolerlance ability of the 165 barley DH lines were appreciated by the new way, which led to the classification of 165 lines into 3 different levels of tolerance. According to the result of the two years, 25, 25 and 0 lines were classified as waterlogging tolerant, medium tolerant and sensitive, respectively.(4) The types of the gene interactions were analysed by estimation for coefficients of skewness(g1) and kortosis(g2) of the traits. In the years 04-05 and 05-06, the remarkable epistasis actions were detected for PH, TFIL, SPP and WTG, and the types were complementary interactions; The epistasis actions were not detected for GWPP, SWPP, GPP; The complementary interaction was detected for GPS in the year 04-05, but were not detected in year 05-06. And the complementary interactions were detected for SL in the year 05-06, but were not detected in year 04-05.