Study On Difference And Stability Of Wet-tolerance In Barley Varieties

The influence of water-logging on the growth and the yield is a hotspot in wet-tolerance research in drought crops. Recent years, more and more attentions were focused on identification and investigation of wet-tolerance barley varieties in the countries which take up the main parts of the world production. 15 barley varieties were treated with water-logging at seedling stage and elongation stage in 3 years with no treatment as the control. The difference and stability of the effects on seedling traits (leaf age, the tiller number, and the yellow-leaf number) for seedling water-logging and on individual traits (plant height, internode below spike, spike length, kernels of main spike, spikes per plant, dry matter weight per plant, kernel weight per plant, kernels per plant, and 1000-grain weight) for the seedling and elongation water-logging were investigated among varieties. The results are as follows.The seedling water-logging restrained plant growth severely, which led to the decrease of tiller number before winter and the increase of yellow leaves. The average of wet-tolerance index of the tiller number before winter was only 40.32%. In addition, the average of wet tolerance index of tiller number at the elongation stage was about 64.18%, which indicated the recovering ability of tillering widely existed in barley, but different varieties showed different recovering ability. The Zhenongda 4, Yangyin 02 and Sunong 16 showed powerful recovering ability, while Franklin was listed as the last. ANOVA analysis suggested that yellow-leaf ratio of caulis showed significant difference in varieties, which indicated that it can be applied as primary index for identifying wet-tolerance at seedling stage, such as Rugaozaoliuleng showed the strongest wet tolerance with the least yellow-leaf ratio. Principal component analysis was performed on 9 characters of per-plant. The result suggested that 6 traits (kernel weight, dry matter weight and kernels per plant, 1000-grain weight, length and kernels of main spike) had the highest coefficient among principal components. Kernel weight per plant, the important index of estimating the degree of water-logging at the seedling stage, showed the highest coefficient in the first principal component.The ANOVA analysis of individual plant traits under water-logging at the elongation stage indicated that the effect of water-logging on barley was influenced by the climate and genotypes. Two years'results showed that water-logging slightly affected the plant height, internode below spike, and 1000-grain weight, but strongly affected spikes, dry matter weight and kernels per plant, and other yield correlated factors. Furthermore, the influence of water-logging on spikes per plant in 2004 was more serious than that in 2005, while the influence on dry matter weight per plant was opposite. Meanwhile, there were great differences in wet tolerance index of spikes per plant among varieties in the 2 years. In 2004, among the three main principal components, the coefficients of 1000-grain weight, the last inter-node length, dry matter weight, kernel weight and spikes per plant were high,while these of the last inter-node length, kernels of main spike, spikes, kernels, kernel weight and dry matter weight per plant were high in 2005. Thereforce, kernel weight per plant and the other correlated factors can be used as the main indexes to identify wet tolerance at the elongation stage.The correlation analysis of water-logging tolerance indices indicated that: significant correlations were presented between the spike length and kernels of main spike, the dry matter weight per plant and kernel weight per plant. There were significant pairwise correlations among spikes, kernels, dry matter weight and kernel weight per plant at elongation stage, and among kernels, dry matter weight and kernel weight per plan at seedling stage. In addition, the correlation between other indices varied from years and stages.Cluster analysis suggested that Rugaozaoliuleng is the wet tolerance variety with high stability. Mimai and Yongjiahongliuleng showed the moderated water-logging tolerance at seedling stage and high tolerance at elongation stage respectively. Yang0187, YangQS and Yan96001 are susceptible to waterlogging because they had shown low wet tolerance at both seedling stage and elongation stage.The result that the influence of water-logging on individual yield traits at the elongation stage was more serious than that at the seedling stage, was in accordance with former researches. And it suggested the stage for identifying the wet-tolerance of barley varieties should be selected according to the local situation.