辽东南地区玉米品种灌浆与脱水特性研究

Study on Grain Filling and Dehydration Characteristics of Maize Hybrids in Southeast Region of Liaoning Province

选用不同熟期玉米品种分析其产量、灌浆特性与籽粒含水量变化,结果表明:中晚熟品种产量(8 840.2kg/hm2)显著高于中早熟品种(7 656.9kg/hm2),中晚熟品种百粒重显著提高(38.0g);早熟品种丹8439、利民33灌浆启动快,后期灌浆速率下降迅速;中晚熟品种丹8662、丹8420、桥玉8生育后期灌浆速率下降缓慢,百粒重显著高于中早熟品种;灌浆持续期早熟品种丹8439、利民33为52,53d,丹8662、丹8420、桥玉8分别为64,63,63d;不同熟期品种最大灌浆速率(Rmax)在1.2~1.3g/d范围内,品种之间差异不显著。在生理成熟前,丹8439籽粒脱水速率最快,中晚熟品种较慢,生理成熟后各品种籽粒含水量下降程度相似,至10月26日观测结束时,中早熟品种丹8439、利民33籽粒含水量分别为20.4%、21.1%,中晚熟品种为20.4%~26.3%。由此得出,在辽东南地区中早熟品种后期籽粒脱水速率快,但花后灌浆持续期短,产量降低严重,不利于实现高产;中晚熟品种灌浆持续期长,但成熟时籽粒含水量高,不利于机收。选择立秆性能好的中晚熟品种并延迟收获,能够实现高产与机械粒收。

Maize hybrids at different mature stages were selected to analyze their yield,grain filling characteristics and grain moisture content changes.The results showed that the yield of mid-late maturity(MLM)hybrids(8 840.2 kg/hm 2)was significantly higher than that of early-medium maturity(EMM)hybrids(7 656.9 kg/hm 2),and the 100-grain weight of medium and late mature varieties was significantly increased(38.0 g).EMM hybrids Dan 8439 and Limin 33 initiated the grain-filling faster compared with the MLM hybrids,while grain filling rate declined rapidly in the late of growth period;In the later growth stage,the grain filling rate of MLM hybrids Dan 8662,Dan 8420,Qiaoyu 8 declined slowly,and the 100-grain weight was significantly higher than that of the medium-early mature varieties.Grain-filling duration of EMM hybrid Dan 8439,Limin 33,Dan 8662,Dan 8420 and Qiaoyu 8 was respectively 52 d,53 d,64 d,63 d and 63 d;The maximum grain-filling rate(R max)of hybrids with different maturities varieties was within the range of 1.2-1.3 g/d,and there was no significant difference among varieties.Before physiological maturation,the grain dehydration rate of Dan 8439 was the fastest,and that of medium and late maturing varieties was slower.After physiological maturation,grain moisture content of each variety decreased in similar degree.By the end of the observation on October 26,grain moisture content of Dan 8439 and Limin 33 of EMM hybrids was respectively 20.4%and 21.1%,and that of MLM hybrids were range from 20.4%to 26.3%.It was concluded that the dehydration rate of EME hybrids in the late period was fast,but the grain filling duration of post-flowering was short and the yield was reduced seriously,which was not conducive to the realization of high yield.The grain filling duration of mid-late maturity hybrids was long,but the grain moisture content was high at the time of maturity,which was not beneficial to mechanization.High yield and mechanization can be achieved by selecting MLM hybrids with good performance of standing stalk and delayed harvest.