水分胁迫对夏玉米干物质积累与分配的影响

采用盆栽方法,通过设置不同的水分处理,研究水分胁迫对夏玉米生长发育的影响.从根、茎秆、叶、叶鞘、雌穗等器官水平上考察水分胁迫对夏玉米物质积累、分配等的影响,以及不同水分处理下各器官对夏玉米干物质积累的贡献率.分析发现,不同水分条件下,叶片、茎秆和叶鞘三者是干物质积累的重要来源,在灌浆期以前,叶片是最主要的干物质积累器官.在灌浆前后期,叶片所占的比重分别为22%,21%;茎秆也是夏玉米干物质积累的来源之一,在抽雄初期,T_3茎秆占总重的26%,在抽雄后期T_4茎秆比重为30%.茎秆在吐丝期和灌浆后期的比重分别为24%和23%,而水分胁迫(T_8)的叶鞘比重分别为21%和18%;在生殖生长阶段,植株对水分胁迫非常敏感;水分胁迫下有利于干物质的快速积累,即缩短灌浆期.

Effect of Water Stress on Dry-matter Partition of Summer Maize

The effects of water stress on dry-matter accumulation and distribution for summer maize Ludan 981 were studied including the different organs from tasseling stage to flowering period using potted method under different water condition, such as roots, stems, leaves, leaf sheath, ears, tassels and so on, and also the contribution ratio of these organs to the total output. The main results were as follows. Leaves, stems and leaf sheath were the very important resources for dry-matter accumulation under different water stress, and leaves were the most important organs for the dry-matter accumulation before the seed filling stage. During the early and late seed filling stage, the proportions of the leaf contribution ratio were 22% and 21%. The stems were also one of the resources of dry-matter accumulation. At the early seed filling stage, the proportion of the T_3 stem contribution ratio was 26%, while that of T_4 is 30% at the late tasseling stage. In the silking stage and the late seed filling stage, the proportions of the stems contribution ratio were 24% and 23% ,and the proportions of leaf sheath contribution ratio were 21% ,18% respectivey. During the generative growth phase, summer maize was very sensitive to water stress. It was very beneficial to the rapid accumulation of dry matter, that is, the conditions of water stress can shorten the period of the seed filling stage.