Molecular Detection Of Vernalization Genes And Analysis Of Agronomic And Root Traits In Wheat Varieties

Wheat is an important food crop, the stability of wheat yield is related to our country's food security. Vernalization characteristics, agronomic and root traits of wheat are important feature of variety adaptability. Understanding of these features of the wheat cultivars and local varieties from different regions has important theoretical and practical significance of reasonable choice of parents in crossbreeding and cultivating wide adaptability, high yield, and mutiple resistance wheat varieties. Therefore, I have detected vernalization genes of wheat varieties and landraces from the Chinese major wheat ecological regions, analyzed the relationship of vernalization genes and winter hardness of varieties in different wheat ecological regions. Agronomic traits and root traits were investigated and analyzed. The main results are as follows:1. To understand the distribution of vernalization genes in Chinese wheat varieties and their relations with winter hardness are important to promote the reasonable utilization of those varieties in wheat improvement. Using STS markers of wheat vernalization genes Vrn-A1, Vrn-B1, Vrn-D1 and Vrn-B3, the loci distribution of those genes among 146 wheat landraces and 86 wheat cultivars from Chinese 10 major wheat ecological regions were detected, and their relationship with winter hardness is analyzed. The frequencies of the dominant loci of the four vernalization genes in Chinese wheat landraces are Vrn-D1(61.64%), Vrn-A1a(4.80%), Vrn-B1(3.43%) and Vrn-B3(0%), respectively. The frequencies of the dominant loci of the four vernalization genes in Chinese wheat cultivars are Vrn-D1(41.67%), Vrn-B1(21.43%), Vrn-A1a(10.71%), and Vrn-B3(0%), respectively. The higher frequencies of Vrn-A1a and Vrn-B1 were detected in spring wheat regions, with highest in Northeastern China Spring Wheat Region and Northwestern China Spring Wheat Region, while in most winter wheat regions, those loci weren't detected. Vrn-D1 was detected in all the 10 wheat ecological regions, which also was the main locus of vernalization genes in the landraces of winter wheat regions in China and the highest frequency was detected in Qinghai-Tibet Spring-winter Wheat Region and Southern China Winter Wheat Region. The genotypes of vernalization genes in wheat varieties from 10 major wheat ecological regions of China detected by molecular marker analysis were largely consistent with their vernalization ?requirement, and the consistency index of genotypes detected with the winter hardness recorded from the field was higher in general, while the consistency index for the varieties from the winter wheat regions of central and southern China were lower. The results show that, combining molecular detection of genotype and field investigation of phenotype could reflect the winter hardness of wheat better.2. Using cluster analysis for agronomic traits of the tested materials were analyzed, the results show that in the same hold value, the landraces were clustered into four categories, cultivars were clustered into three categories. Combined with the geographical information of varieties, found that there is a certain relation between the geographical distribution and the classification results, but no direct relation between the two. Comparison of agronomic performance of landraces and cultivars found that the plant height, internode blow ear and coleoptile length of the cultivars are shorter than the landraces, probably because in recent decades, the cultivars carry dwarfing Rht-B1b and Rht-D1b.3. Using correlation analysis and cluster analysis of the tested materials for root traits were analyzed, results showed that the cultivars has more developed root system than cultivars, and able to absorb water and nutrients from the soil better. Most of the root traits showed highly significant positive correlation between each two of them. Evaluation of cultivars, the future when we measure whether the root system of varieties is developed, we can choose a root trait which is easier to be measured, as an alternative indicator to response whether the root system of varieties is developed indirectly.