Mapping QTL Related To Nitrogen Use Efficiency In Brassica Rapa

Chinese cabbage is an important Brassica vegetables and oil crops in the national economy and have a increasingly important position in the development, Chinese cabbage crop nitrogen use efficiency has become a hot issue of wide concern, breeding species to improve the efficient use of nitrogen fertilizer utilization is the most useful effective way. In this study, a nitrogen use efficiency of the DH lines under the normal nitrogen (10cM) and low nitrogen (3cM) conditions to investigate the overall characteristics of the Chinese cabbage plant triaits and leaf traits, QTL for different sowing time, sowing and the same dynamic QTL analysis, the main conclusions are as follows:Compare with the taits in both nitrogen conditions,it is found that the traits grown in the normal nitrogen is higher than the low condition.Parent L144 in the two nitrogen is more Sensitive than Z16.It was indicated that Z16 maybe have more nitrogen use efficiency.In the all traits,single leaf weight and leaf area is the Most affected by the nitrogen.In the single nitrogen levels,the parents.It was nearly in the same time to invest the spring time and the first time of autumn growing season,but in the spring time traits is lower than the first autumn invest,it maybe because in the spring time the temperature is a little higher that the growth of Chinese cabbage stress played a certain role,resulting in weak plant growth, the environment influenced the results of the QTL, but still detected more important QTL.The triats in the spring did not detected co-localization in diffierent nitrogen but found QTL co-localization with other survey times. One of the single leaf weight QTL is co-localization with a QTL of petiole aspect ratio in the first time of autumn ;another petiole aspect ratio also found a co-localization with the first time of autumn. The result of diffierent investigate time in the autumn was showed that the leaf traits is very different in the two nitrogen conditions but the plant traits only in the second investigate time have clear different.. QTL for dynamic traits in the autumn survey for the first time the survey detected more QTL for the leaf traits, the second survey in the autumn the whole plant traits detected QTL has increased significantly. The results of two surveys QTL loci were targeted less, indicating that the efficiency of different control points during the N gene expression is not identical.In the first investigate of autumn some traits were co-localization with each other,it means maybe they were controled with the same gene.This experiment in the low nitrogen detected QTL may be related to nitrogen efficiency in nitrogen specific expression under low nitrogen conditions and from the perspective of the contribution rate,QTL detected in both nitrogen level and the contribution rate in the low nitirogen is higher than in the nomal conditions,these QTL ,maybe useful for molecular markers in breeding.