油菜氮素吸收效率的基因型差异及其与农艺性状的关系

Relationship between genotypic differences of rapeseed ( Brassica napus L. ) nitrogen uptake efficiency and economic characteristics

采用土培试验,在不同供氮水平下,对50份甘蓝型油菜材料进行氮素吸收效率筛选。结果表明,不同油菜基因型的氮素吸收效率具有显著差异,氮素供应水平较高时不同基因型氮素吸收效率的变异更大;在油菜各器官生物量、各生育期地上部生物量、各器官生物量占总生物量的比例和各种农艺性状等指标中,根系生物量差异最大,表明根系生物量可能是评价油菜氮素吸收效率的重要指标。氮素供应水平较高时,氮高效基因型与氮低效基因型地上部生物量的差异从五叶期到成熟期呈增高的趋势,有效角果数、株高和第一个有效分枝高度差异显著;而施氮水平较低时,地上部生物量差异不显著,千粒重和每角粒数差异也不显著。供氮水平改变时,氮高效基因型的油菜生物量、籽粒产量和茎叶生物量占总生物量的比例及多个农艺性状指标都有显著变化,而氮低效基因型的相应指标变化则较小,表明氮高效基因型对氮素供应水平更敏感。

Pot experiment was conducted to test nitrogen （ N） uptake efficiency of 50 rapeseed genotypes at two N levels. Results showed that N uptake efficiency varied significantly among different genotypes. Great variance was found under higher N level especially on root biomass which indicated that root biomass was one of the valuable indexes to screen N-efficient genotypes. When higher N fertilizer was applied,the shoot biomass difference between high and low N efficiency genotypes increased,but varied little when lower N applied. High N efficiency genotypes had significantly more silique per plant,higher plant and longer first valid branch. When N level changed,high N efficiency genotypes＇ agronomic characteristics changed remarkably. The characteristics included biomass,percentage of grain yield to whole biomass,percentage of stem and leaves weight to whole biomass. On the contrary,the indexes of N-inefficient genotypes varied little. This result indicated that N-efficient genotypes were more sensitive to N fertilizer.