花期弱光持续时间对玉米果穗发育及产量的影响

为探明花期连阴雨造成的弱光胁迫持续时间对玉米产量的影响,以黄淮海平原主推夏玉米品种浚单29为材料,自抽雄期起设置弱光胁迫处理0 d(CK)、3 d(S3)、6 d(S6)、9 d(S9)、12 d(S12)、15 d(S15)6个处理,探讨了玉米花期弱光持续时间对玉米果穗发育及产量的影响。结果表明,自抽雄期起,随着弱光胁迫时间的延长,弱光处理3~15 d,吐丝期较CK推迟1~7 d,终散粉日较CK推迟1~2 d。在抽穗后第11天所有处理散粉全部结束。散粉100%结束日吐丝株率较CK减少3%~43%,各处理结束日果穗长度的增长速率和雌穗干质量增长速率分别较CK降低71%~79%和83%~100%,但对最终的苞叶长度无显著影响。弱光处理3~15 d,导致受精率和结实率较CK分别降低22~58,16~71个百分点(P0.05)。抽雄期起3~15 d的弱光胁迫显著降低了植株干物质积累速率,恢复自然光照后,干物质积累速率呈现恢复性增长,但仍低于CK。随着弱光胁迫持续时间的延长,成熟期果穗长度、结实长度显著降低,秃尖长度显著增加,穗粒数和籽粒产量显著降低(P0.05),百粒质量无显著变化。

Effects of Low Light Duration Since Tasselling on Maize Ear Development and Yield

The aim of this study was to explore the effects of prolonged overcast and rainy days duration during flowering on maize yield.Here, Xundan 29, a widely used maize variety in Huang-Huai-Hai region was used.Six shading treatments since tasselling which lasts 0 days(CK), 3 days(S3), 6 days(S6), 9 days(S9), 12 days(S12) and 15 days(S15)were set to explore different low light stress duration during flowering stage on maize ear development and yield.The result indicated that accompany low light stress duration elongation since tasselling, low light stress lasts 3-15 days result a 1-7 days delay of silking dates, and 1-2 days delay of pollen shedding ending dates.All treatments finished pollen shedding at 11 days after tasselling, and silking rate at the end of pollen shedding dates decreased 3%-43%.Compared with CK, ear elongation rate and ear dry matter (DM) accumulation rate at the end of each treatments of S3-S15 decreased 71%-79%and 83%-100%, respectively.There was little influence on the final husk length.Fertilizing rate and kernel setting rate decreased 22-58 and 16-71 percentage under 3-15 days shading treatment(P<0.05).Low light stress since tasselling stage reduced plant DM accumulation rate.DM accumulation rate exhibit recovery growth after shading removed, but the DM accumulation rate was still lower than CK.Ear length and kernel setting length were reduced significantly, ear barren length was increased significantly, and kernel number per ear and grain yield decreased significantly in accordance with low light stress duration elongation(P<0.05).There was no significant variation of 100 kernel weight between each treatment.