水稻苗期氮素吸收利用效率的遗传分析

利用主基因 多基因混合遗传模型，对由韭菜青×IR26杂交和自交构建的一个由220个家系组成的重组自交系群体 (F8)的苗期吸氮能力和氮素生理利用率进行了遗传分析。水稻苗期硝态氮吸收能力、铵态氮吸收能力和氮素生理利用率均由两对主基因+多基因模式控制。硝态氮吸收能力的主基因遗传率为6320%，多基因遗传率为20.64%，两对主基因之间有加性和上位性效应；铵态氮吸收能力的主基因遗传率为55.67%，多基因遗传率为0.03%，两对主基因之间具有显性上位性效应；氮素生理利用率的主基因遗传率仅为19.47%，多基因遗传率达67.46%，两对基因之间具有重叠效应。对水稻氮高效利用品种的选育策略进行了讨论。

Genetic Analyses on Nitrogen-Absorbing Ability and Nitrogen-Utilizing Efficiency of Rice at the Seedling Stage

A RILs population consisting of 220 lines(F_(8)) derived from the cross between rice variety Jiucaiqing(japonica) and IR26 (indica) was evaluated to analyze inheritance of nitrogen-absorbing(NA) ability and physiological use efficiency(NUE) at the seedling stage by using the major gene plus polygene mixed inheritance model.The NO_3~-absorbency,NH_4~ absorbency and NUE of rice seedlings were genetically controlled by genetic mode of two major genes plus polygenes.The heritability values of major genes for NO_3~-absorbency,NH_4~ absorbency and NUE were 63.20%,55.67% and 19.47%,respectively,and the values of polygene for the three traits were 20.64%,0.03% and 67.46%.There were additive and epistasis effects for the NO_3~-absorbency,epistasis effect for the NH_4~ absorbency and cumulative effect for the NUE respectively between each two major genes.The strategy to breed new rice variety with high absorbing ability and use efficiency of nitrogen was discussed.