不同基因型的玉米品种在氮素吸收利用效率上存在较大差异。综述了玉米氮效率的类型划分、目前研究的焦点与不足,指出了未来研究关注的方向。玉米氮效率的评价方法与指标不尽一致,导致对玉米基因型不同的分类结果。玉米氮效率研究主要集中于根系对氮素的吸收、叶片对氮素的还原同化、氮素在植株体内的积累和分配以及地上部生长势与氮效率的关系方面。对以籽粒为主要收获对象的玉米,穗、籽粒发育状况对玉米产量起着关键的作用,但目前有关穗、籽粒发育对玉米氮效率贡献率的大小、不同氮效率基因型玉米穗、籽粒发育的差异以及内在生理生化机制研究较少。对不同氮效率基因型玉米而言,籽粒发育与氮效率之间有何关系？籽粒发育尤其是顶部籽粒的早期发育(决定穗粒数的形成)对氮素的反应有何不同？氮高效品种顶部籽粒的早期发育是否优于氮低效型？氮素对不同氮效率基因型玉米籽粒发育的影响机制如何？这些问题尚待进一步研究。
英文摘要:
Different genotypes of maize differ significantly in nitrogen(N) absorption and utilization efficiency. Maize genotypes with different nitrogen use efficiency(NUE), the focus and shortage of the research on NUE in maize were summarized, and the future research directions were pointed out. The evaluation method and index of NUE in maize were different, which resulted in different classification of maize genotypes. Current research mainly concentrated in roots of N absorption, leaves of N reduction and assimilation, plants of N accumulation and distribution, and the relationship between the growth potential in aboveground parts and NUE. However, the ear and kernel development played a key role in maize yield with grains as main harvest object. But at present, the contribution rate of ear and kernel development to maize NUE, the differences of ear and kernel development between different genotypes and its physiological and biochemical mechanism were studied less. What is the relationship between kernel development and NUE in different maize genotypes? Kernel development, especially the early development of apical kernel(determine kernel number) reacted to N differently? Is the early development of apical kernel in high N efficient varieties better than that in N inefficient types? What is the mechanism of N influence kernel development in maize genotypes with different NUE. These questions need to be further studied.
;
