不同熟期类型玉米品种籽粒灌浆和脱水特性

根据自然生态条件及玉米品种的熟期、籽粒灌浆与脱水特性和产量潜力等进行科学品种布局,是实现玉米高产优质和资源高效利用的重要途径。本试验选用中早熟、中熟和中晚熟3个熟期类型,共13个玉米生产主栽品种,通过测定籽粒干物质积累和含水率的动态变化,研究并明确了不同熟期类型玉米品种的籽粒灌浆和脱水特性,旨在为生产品种布局提供参考和指导。试验结果表明:产量、籽粒灌浆和脱水特性在不同熟期类型和品种间均存在显著差异。产量表现为中晚熟(13,813.0 kg hm^–2)>中熟(12,970.4 kg hm^–2)>中早熟品种(10,729.0 kg hm^–2),中晚熟分别较中早熟和中熟品种增产28.7%和6.5%。平均灌浆速率表现为中早熟(0.034 g 100-grain^–1℃^–1)>中熟(0.031g 100-grain^–1℃^–1)>中晚熟品种(0.027 g 100-grain^–1℃^–1),生理成熟后的平均物理脱水速率表现为中熟(0.027%℃^–1 d–1)>中早熟(0.025%℃^–1 d–1)>中晚熟品种(0.018%℃^–1 d–1)。中早熟代表性品种京农科728的平均灌浆速率和生理成熟后的物理脱水速率。分别较3个熟期代表性品种郑单958、先玉335、农华101高38.5%和112.5%、28.6%和54.5%、28.6%和13.3%;中晚熟代表性品种京科968产量潜力最大(14,813.0 kg hm^–2),且平均灌浆速率和物理脱水速率分别较同熟期品种郑单958高7.7%和18.8%。产量与灌浆期天数、积温、平均灌浆速率和百粒重呈显著或极显著正相关,收获期籽粒含水率与灌浆期天数和积温显著正相关、与生理降水速率和物理脱水速率极显著负相关,生理降水速率和物理脱水速率与平均灌浆速率相关性不显著。综上,中早熟、中熟和中晚熟3个不同熟期类型及不同玉米品种的籽粒灌浆和脱水特性差异显著,生产中品种布局除考虑熟期外还需兼顾该特性,以更利于实现玉米高产优质和资源高效利用。

Grain filling and dehydrating characteristics of maize hybrids with different maturity

Suitable variety arrangement according to the natural ecological conditions,maturity,grain filling and dehydrating characteristics and yield potential of maize hybrid is an important approach for realizing higher maize yield,quality and photothermal resource utilization.Thirteen hybrids widely planted in maize production with three maturity types[medium-early maturity(MEM),medium maturity(MM)and medium-late maturity type(MLM)]were selected to clarify the grain filling and dehydrating characteristics for different maturity hybrids,by investigating the dynamic changes of grain filling and moisture content.The results showed that yield,grain filling and dehydrating characteristics differed significantly between different maturities and hybrids.Average yield level showed MLM(13,813.0 kg hm^–2)>MM(12,970.4 kg hm^–2)>MEM(10,729.0 kg hm^–2),with MLM was 28.7%and 6.5%higher than that of MLM and MM type,respectively.Average grain filling rate showed MEM(0.034 g100-grain^–1℃^–1)>MM(0.031 g 100-grain^–1℃^–1)>MLM(0.027 g 100-grain^–1℃^–1),average dehydrating rate after physiological maturity(PM)showed MM(0.027%℃^–1 d–1)>MEM(0.025%℃^–1 d–1)>MLM(0.018%℃^–1 d–1).Average grain filling rate and dehydrating rate after PM of MEM representative hybrid Jingnongke 728 were 38.5%and 112.5%,28.6%and 54.5%,28.6%and 13.3%higher than those of representative hybrid Zhengdan 958,Xianyu 335 and Nonghua 101 for three maturity type;the yield of Jingke 968 was the highest(14,813.0 kg hm^–2),average grain filling rate and dehydrating rate after PM was 7.7%and 18.8%higher than the same maturity hybrid Zhengdan 958.Yield level was significantly or extremely significantly correlated with grain filling period,corresponding accumulated temperature,average grain filling rate and 100-grain weight;grain moisture content at harvest stage was significantly correlated with grain filling period and corresponding accumulated temperature,but negatively significantly correlated with dehydrating rate before and after PM;there were no significant correlation between dehydrating rate before and after PM with average grain filling rate.Maturity,grain filling and dehydrating characteristics were all important factors for higher maize yield,quality and photothermal resource utilization.This study indicated that maize grain filling and dehydrating characteristics differed significantly between different maturity types and hybrids.Maturity,grain filling and dehydrating characteristics should be well considered for variety arrangement in maize production in order to achieve higher maize yield,quality and photothermal resource utilization.