The Correlation Analysis Between Yield And Agronomic Traits In Tibetan Wild Barley And The Gene Mapping Of Yellow Leaves Mutants

Barley is one of the important crops in the world, high yield has been the main direction of barley breeding and cultivation. Barley yield is influenced by various factors.This dissertation took Tibetan wild barley and yellow leaves mutant treated by EMS as material, This study analyzed the association between the yield and agronomic traits and made the gene analysis and gene mapping of the leaves yellowing genes which influenced the barley yield.Finding out the dominant trait of Tibet wild barley yield in the climate conditions of Hangzhou. Understanding the genetic mechanism of yellow leaf gene through the molecular level. The main research results are as follows:The correlation analysis of Tibetan wild barley yield and agronomic traits:1. We selected 40 species of Tibetan wild barley varieties, including 20 species of two-row barley,20 species of six-row barley, and analyzed statistically the range and variation coefficient of their agronomic characters.Clear character differences were observed within the group or between groups. These results showed that the genetic diversity was abundant in Tibet wild barley.2. Correlation analysis was carried out on the six-row Tibet wild barley, and the correlation between the various characters and yield size were arranged in order: hundred -grain weight> plant height> grain number> ear length> length of uppermost internode> tiller number> awn length. Through path analysis and multiple stepwise regression analysis, we found that the plant height, hundred grain weight, grain number and tiller number was associated significantly with the production. The directly correlation coefficient of the hundred grain weight was 0.829, which was the highest among them. Indirect correlation coefficient between different traits was positive or negative value. Under the climate conditions of Hangzhou, the optimal traits of six-row Tibetan wild barley should be that high hundred-grain weight moderate plant height(king rod, dwarf rod), relatively small tiller number and grain number, paid attention to the coordination between each trait at the same time.3. Correlation analysis was carried out on the two-row Tibet wild barley, and the correlation between the various characters and yield size were arranged in order:grain number> plant height> awn length> ear length> tiller number> hundred-grain weight> length of uppermost internode. Through path analysis and multiple stepwise regression analysis, we found that plant height, spike length, awn length, grain number and tiller number was associated with the yield.The directly correlation coefficient of the grain number was 0.829, which was the highest among them. Correlation between different traits was complex.Under the condition of different traits developed concertedly, the optimal traits of two-row Tibetan wild barley should be that medium plant height(king rod, dwarf rod), medium ear length, medium to long awn length, much grain number.The research of yellow leaves mutant:1. Through the observation of the yellow leaves mutant barley YLM and the measurement of agronomic traits of YLM and ZAU3, the yellow leaves mutant was always yellow during the whole growth period and the growth period was extended. Compared with the control varieties,the plant height, spike length, awn length are longer.As for the mature plant stem weight, grain weight and single plant yield,the values of these traits are significantly lower than the control varieties.the yield of YLM was decreased significantly.2. Genetic analysis indicated that in the F2 population crossed by YLM mutant and XZ181, a total of 142 wild type plants and 58 yellow leaves plants were obtained. The segregation rate of the wild type and YLM mutation fited a ratio of 3:1(χ2= 1.71< χ20.05= 3.84), demonstrating that the mutant phenotype of the yellow leaves was controlled by a single recessive gene.3.416 pairs of SSR molecular marker were used for gene mapping.The yellow leaves gene ylm-1 was found to be located between the SSR markers 3H545 and 3H550 on the long arm of chromosome 3, the physical distance spacing is 7 Mb.