“油-稻-稻”三熟制早熟冬油菜氮高效基因型及鉴定指标筛选

Selection of high nitrogen utilizing rate winter rapeseed genotypes and evaluation indexes in“Rapeseed-Rice-Rice”triple-cropping system

【目的】旨在筛选适宜“油-稻-稻”三熟制的氮高效早熟冬油菜基因型及其简易筛选指标。【方法】利用田间小区试验,选用了生育期185 d以下的的适宜“油-稻-稻”三熟制种植的14种早熟冬油菜基因型,进行正常施氮(N_(1))和不施氮(N_(0))处理。根据不同冬油菜基因型氮肥利用率(NUE)的差异,利用树状聚类分析进行分类,形成高、中、低3种氮效率基因型。同时通过逆向溯源的方法,观察分析3种氮效率基因型在不同氮水平条件下的产量构成、主要农艺性状、干物质积累及氮素吸收等方面的表现特征。总结分析出氮高效冬油菜基因型的一些简易判断的指标。【结果】不同氮效率基因型冬油菜在产量形成、主要农艺性状等方面存在显著差异。N1处理下成熟期早熟冬油菜的主要农艺性状的表型值和变异系数基本表现大于N0处理。因此,以N1处理下不同基因型的农艺性状表现作为不同氮效率基因型的鉴别标准。N1处理下,氮高效基因型比氮中效和氮低效基因型产量高、单株角果数多、每角粒数多、株高高、主花序长、一级分枝数多、角果密度高、各部位干物质积累量高、籽粒中氮含量高、氮肥偏生产力、氮肥农学效率、氮肥生理利用率和氮收获指数均较高。【结论】沣油737是适合南方“油-稻-稻”三熟制的氮高效早熟冬油菜;正常施氮条件下,成熟期较多的单株角果数与每角粒数,以及较高株高是判断早熟冬油菜氮高效基因型的简易指标。

[Objective]This study aims to select the genotype of high nitrogen use efficient in early winter rapeseed and its simple selecting indexes,which is suitable for“rapeseed-rice-rice”triple cropping system.[Method]14 early winter rapeseed genotypes(the growth period is less than 185 days)suitable for“rapeseedrice-rice”triple cropping system were selected and treated with normal nitrogen(N_(1))and no nitrogen(N_(0))in field conditions.According to the difference of nitrogen use efficiency(NUE)of different winter rapeseed genotypes,3 type of NUE genotypes,high,medium and low,were classified by tree cluster analysis.the yield and its composition,main agronomic traits,dry matter accumulation and nitrogen uptake and usage of 3 NUE types under different nitrogen levels were observed and analyzed by reverse tracing.Indexes for judging the genotype of high NUE winter rapeseed genotype were summarized and analyzed[.Result]There were significant differences in yield formation and main agronomic traits of winter rapeseed genotypes with different NUE.The phenotypic values and coefficient of variation of main agronomic traits of early winter rapeseed genotypes at maturity stage were higher under N1 treatment than those under N0 treatment.Therefore,the agronomic traits of different genotypes treated with N1 were used as the criteria for the identification of different NUE genotypes.Under N1 treatment,the yield,siliqua number per plant,seed number per siliqua,plant height,main inflorescence length,primary branch number,pod density,dry matter accumulation in different parts,nitrogen content in grain,partial factor productivity of nitrogen fertilizer,agronomic efficiency of nitrogen fertilizer,physiological utilization efficiency of nitrogen fertilizer and nitrogen harvest index of N efficient genotype were higher than those of N medium and N inefficient genotypes.[Conclusion]Fengyou 737 is a high NUE early winter rapeseed genotype suitable for triple cropping system of“rapeseed-rice-rice”in South China.Under normal nitrogen application conditions,the number of siliquas per plant,the number of seeds per siliqua and the high plant height were indexes to judge the high NUE genotype of early winter rapeseed.