不同基因型小麦产量和氮利用效率的差异及其相互关系

为给氮高效利用小麦品种的选育提供科学依据,通过土培盆栽试验,以河南省大面积种植的20个小麦品种为材料,比较分析了不施氮(N0)、施纯氮180 kg·hm-2 (N180)、360 kg·hm-2 (N360)三种施氮水平下不同基因型小麦产量、氮素积累量、氮利用效率和氮响应度的差异及其相互关系.结果表明,在同一施氮水平下,不同基因型间、相同基因型不同施氮水平间小麦产量、氮积累总量、氮利用效率和氮响应度存在显著差异.与N0相比,施氮处理的籽粒产量、生物学产量、籽粒氮素积累量、氮素积累总量均显著提高,大多数品种的收获指数表现为施氮处理大于不施氮处理,但多数小麦品种的氮素收获指数却随施氮水平增加而降低.相关分析表明,籽粒产量与氮素积累量呈极显著正相关(rN0=0.944**,rN180＝0.919**,rNs60＝0.981**),氮利用效率与氮素积累量之间亦呈极显著正相关(rN0=0.944*,rN180 =0.919*,rN360＝0.982*).以氮利用效率和氮响应度为指标进行系统聚类分析,将供试基因型划分为高效弱响应、高效强响应、低效弱响应和低效强响应4种类型.由此说明,在现代高产小麦的育种过程中,高肥育种兼顾低肥水平下的表现,在一定范围内可同时对小麦氮高效利用和氮强响应型进行遗传选择.

Differences in Grain Yield,Nitrogen Efficiency of Different Genotypes of Winter Wheat and Their Correlations

To provide the scientific basis for the development of wheat varieties with high nitrogen (N) efficiency and wheat cultivation.In this experiment,twenty wheat varieties widely planted in Henan province,were used to compare their differences in grain yields,nitrogen accumulated amounts,nitrogen use efficiency and nitrogen response and estimate their relations in order to select varieties with high nitrogen use efficiency.Seeds of each wheat variety were sowed in pots with three nitrogen treatments of N₀(no nitrogen),N₁₈₀ (180 kg·hm^-2) and N₃₆₀ (360 kg·hm^-2).The results indicated that there were significantly differences in grain yields,nitrogen accumulated amounts,nitrogen use efficiency and nitrogen response among those wheat varieties under different N application treatments,or among different N application treatments for different wheat varieties.Grain yields,biomass yields,grain nitrogen accumulated amounts,total nitrogen accumulated amounts were significantly higher in N₁₈₀ and N₃₆₀ treatments than those in N₀treatment.However,the harvest index in low nitrogen treatments was markedly higher than that in higher nitrogen treatments.The correlation analysis showed that nitrogen accumulated amounts had a positive and significant correlation with grain yield (r_N0=0.944^**,r_N180=0.919^**,and r_N360=0.981^**),and nitrogen use efficiency had also a positive and significant correlation with nitrogen accumulated amounts (r_N0=0.944^**,r_N180=0.919^**,and r_N360=0.982^**).Cluster analysis based on nitrogen use efficiency and nitrogen response,classified the tested wheat varieties into four groups,as high nitrogen efficiency with weak response,high nitrogen efficiency with strong response,low nitrogen efficiency with weak response and low nitrogen efficiency with strong response.These results suggested that,during the high yield wheat breeding process,selecting wheat germplasm with high N efficiency and strong N response could be conducted simultaneously based on their performance in high fertility levels in combination with low fertility levels.