"油-稻-稻"三熟制早熟冬油菜氮高效基因型及鉴定指标筛选OA北大核心CSTPCD

[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"rapeseed-rice-rice"triple cropping system were selected and treated with normal nitrogen(N1)and no nitrogen(N0)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.