大穗型小麦叶片性状、养分含量及氮素分配特征

采用田间试验研究了8个大穗型小麦新品系和西农979不同生育期比叶面积(SLA)、叶干物质含量(LDMC)与养分含量的差异性,并对其不同器官氮素积累和分配情况进行了探讨。结果表明,大穗型小麦的SLA和LDMC平均值小于西农979;小麦叶片养分含量由大到小依次为全氮(N)、全钾(K)和全磷(P);成熟期大穗型小麦品系各器官平均氮素积累能力都高于对照,氮素积累量及分配比例的大小顺序为籽粒>茎+鞘>穗草(穗轴+颖壳)>旗叶>倒二叶>余叶;大穗型小麦平均转移率和贡献率较西农979低;抽穗期旗叶SLA和LDMC呈负相关关系,SLA和N含量呈不显著的正相关,和P、K呈极显著的负相关。小麦叶片结构性状与养分含量影响体内有机物质的积累与转运,通过水肥调控措施来提高大穗型小麦养分利用效率的研究需进一步加强。

Structural characters and nutrient contents of leaves as well as nitrogen distribution among different organs of big\headed wheat

A field experiment is conducted to study differences between eight new big headed wheat lines and Xinong 979 at different growth stages in specific leaf areas (SLA), leaf dry matter contents (LDMC) and leaf nutrient contents as well as nitrogen accumulations in and distributions among different organs of the lines and variety. The big-headed wheat lines had lower average SLA and LDMC than Xinong 979 and the line 2040 had lower average SLA and higher average LDMC that the latter. The leaf nutrient contents of the big headed lines were ranked in the order of N total > K total > P total and the N content and N/K of the lines first increased and then decreased during the growing period, but the P contents of the lines declined gradually. The big-headed lines had higher average nitrogen accumulation capacities than the control variety at the ripening stage. The nitrogen accumulations in and distributions among the kernels, stem and leaf sheathes, spike stalk and shell, flag leaves and penultimate leaves were ranked in the order of the kernels > the stems and leaf sheathes > the spike stalks and shells > the flag leaves > the penultimate leaves > the other leaves. At the heading stage, The SLA and LDMC of the flag leaves were negatively correlated, The SLA of the flag leaves were insignificantly positively correlated with their N contents but extremely significantly negatively correlated with their P and K contents, which were not significantly positively correlated. In conclusion, leaf structural characters and nutrient contents of wheat influenced organic matter accumulation and transports in its body, and it was imperative to enhance researching on how to improve nutrient use efficiencies of big headed wheat by reasonably regulating its water and fertilizer conditions.