不同基因型小麦苗期耐低氮性评价及筛选

氮素作为重要的营养元素,限制着小麦的生长发育和经济产量,筛选和培育耐低氮小麦品种是提高氮素利用率、降低生产成本的有效途径.以118份不同基因型小麦为材料,在低氮(0.1 mmol·L-1)和正常氮(5 mmol· L-1)条件下苗期水培,测定根干重、茎叶干重、根冠比、植株干重、最大根长、初生根数和二级初生根数等相关指标...

LI Junjie,DU Pufang,SHI Tingrui,HOU Peijia,CHAI Xinyu,ZHAO Rui,WANG Yu,LI Hongxia*

Nitrogen is an important nutrient element and restricts wheat growth and economic yield, so screening and breeding low nitrogen tolerant wheat varieties is an effective way to improve nitrogen utilization rate and reduce production cost. In this study, 118 wheat varieties were grown in low nitrogen (0.1 mmol·L^-1) and normal nitrogen (5 mmol·L^-1) conditions using hydroponic methods. Nitrogen efficiency of plants was measured based on 7 indicators about root dry weight, straw dry weight, root/shoot ratio, plant dry weight, maximum root length, primary root number and secondary primary root. The low nitrogen tolerance of wheat varieties was evaluated by using fuzzy membership function method, principal component analysis and cluster analysis. The results showed that the root dry weight, root/shoot ratio and primary root number of wheat seedlings significantly increased, the stem and leaf dry weight, plant dry weight and maximum root length decreased in different degrees under low nitrogen stress, and the 7 seedling traits were significantly different at the two nitrogen levels. Three principal components were extracted by principal component analysis, and the contribution rate was 43.575%, 22.904% and 17.873%, respectively. The cumulative contribution rate reached to 84.351%. 118 wheat varieties were divided into 5 categories (strong resistance to low nitrogen, resistance to low nitrogen, medium resistance to low nitrogen, nitrogen sensitive, and nitrogen highly sensitive) according to the D value of comprehensive evaluation of low nitrogen tolerance. Qida 195, Jinfeng 7183 and Tianmin 198 were identified as low nitrogen tolerant wheat varieties. Two varieties (Shannong 0917 and Lumai 8) with relatively strong low nitrogen tolerance were screened. There were some obviously differences in the low nitrogen tolerance mechanisms of different wheat varieties. The research results provided theoretical and material basis for breeding of wheat varieties with low nitrogen resistance.