黄淮海地区夏玉米对干旱和涝渍的生理生态反应

利用黄淮海地区多站点的夏玉米水分控制试验,探讨旱涝对夏玉米发育进程、光合能力、干物质分配、叶面积扩展、产量结构及最终产量的影响,进而分析旱涝对夏玉米生长过程的影响机制。结果表明:干旱减缓了夏玉米营养生长阶段的发育速率,但加快了生殖生长阶段的发育进程,而涝渍对夏玉米发育进程的影响较小;夏玉米全生育期土壤湿度距适宜湿度减小1%,其叶片最大光合速率将下降0.3 mol·m~(-2)·s~(-1),比叶面积上升8×10-6hm~2·kg~(-1);夏玉米全生育期土壤相对湿度下降1%,其地上总干重和穗干重均下降0.55%,而产量将减少155kg·hm~(-2);干旱不仅使玉米灌浆时间变短,而且使叶片光合能力下降;营养生长阶段干旱使干物质更多地分配向茎秆,导致叶面积扩展乏力,生殖生长阶段干旱减少干物质向贮存器官的分配而影响产量构成;尽管干旱使叶片变薄而促进其扩展,但仍不足以减缓干旱的整体负面影响,最终导致玉米减产;而涝渍主要使玉米叶片光合能力下降,并导致干物质向穗的分配减少而减产。

Ecophysiological responses of summer maize to drought and waterlogging in Huang-Huai-Hai plain

Quantitative effect of drought and waterlogging on photosynthetic capacity ,dry matter partition ,leaf area growth ,yield structure and yield of maize was analyzed by using water control field test in Huang -Huai -Hai plain . The influence mechanism of drought and waterlogging on the growth of summer maize was then discussed .The results showed that drought slowed the development rate of summer maize during the vegetative growth stage ,while it increased the development rate during the reproductive growth stage .Waterlogging had little effect on summer maize development . Maximum photosynthetic rate was decreased by 0 .54 mol·m-2·s-1 and specific leaf area of summer maize became in-creased by 8 × 10-6 hm2·kg-1 ,while soil moisture from the appropriate humidity during the whole growth period was re-duced by 1% . The total above ground dry weight and dry weight of spike of summer maize would be decreased by 0 .55% and the yield would be reduced by 155 kg·hm-2 ,while soil relative moisture during the whole growth period was decreased by 1% . Drought not only shortened the filling period , but also reduced the leaf photosynthetic capacity . Drought made additional dry matter allocated to stems during the vegetative growth stage ,which resulted in source short-age of leaf area expansion .It reduced the allocation to storage organs at the reproductive growth stage ,which affected yield components .In general ,drought casted a negative influence on the growth of maize ,although it made thinner leaf and promoted its expansion .Drought finally reduced maize yield .Waterlogging decreased photosynthetic capacity and re-duced the distribution of dry matter to spike ,which caused reduction of maize yield .