苗期低温胁迫对玉米生长发育及产量的影响

通过对玉米苗期进行不同低温胁迫试验，研究两个玉米品种（丹玉39、丹玉42）对苗期低温的响应。结果表明，苗期低温胁迫后，两个玉米品种的生长发育及产量存在明显的差异：（1）三叶期—七叶期，低温胁迫处理阶段玉米生长均受到抑制，对丹玉39的影响大于丹玉42；（2）拔节期—乳熟期，经过苗期低温胁迫后，丹玉39后期叶面积逐渐接近并最终在乳熟期达到对照正常水平，而丹玉42的后期恢复能力较差；（3）丹玉42低温胁迫后呈现苗期天数增加、穗期天数减少的趋势，丹玉39无明显变化；（4）成熟后的丹玉42果穗大小、茎杆重、籽粒重和百粒重均小于对照，生物量及产量显著下降，而丹玉39的果穗性状、生物量及产量受影响较小。

Effects of low temperature stress in seedling stage on growth development and yield for maize

Two maize cultivars (Danyu 39, Danyu 42) with low temperature stress in seedling stage were measured. This paper analyzed the growth characteristics and yield of different treatments and their response to low temperature stress in seedling stage. The results showed as follows. (1) From three leaf period to seven leaf period, the growth of leaf area was inhibited during the low temperature treatme nt periods, and the effects on Danyu 39 were greater than those of Danyu 42. (2) From the jointing stage to the milky stage, the leaf area of Danyu 39 increased gradually with growth and eventually reached the control levels in the milky stage. Compared with Danyu 39, the recovery ability of Danyu 42 was low during the whole growing stage. (3) There were effects of low temperature stress on Danyu 42, leading to longer seedling stage and shorter ear stage. But the effects on Danyu 39 were unclear. (4) Compared with the controls, the ear length, ear diameter, stem weight, grain weight and 100 seed weight of Danyu 42 in low temperature treatments were all decreased. However, the effects on Danyu 39 were small.