Roles of roots in successful growth of crop plants.For increasing dry matter production and high water use eficiency.

根在作物成功生长中的作用。用于增加干物质产量和高水分利用效率。

基本信息

批准号：
08044197
负责人：
HIRASAWA Tadashi
金额：
$ 5.82万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

The effects of atmospheric and soil moisture conditions on root system development and root functions and the effects of root functions on growth and dry matter production of crop plants were investigated for increasing water and fertilizer use efficiencies. The following results were obtained.(1) Potato plants were grown in Sapporo, Hokkaido and in Davis, California under irrigated and unirrigated conditions and root system development was compared. The plants grown under unirrigated conditions developed root system well compared with the plants grown under irrigated conditions. However, the plants grown in Davis had a larger and dense root system even under the same irrigation treatment.(2) Simple equations for estimating water use efficiency were derived. These might be applicable to maize and cotton canopies without explicit upscaling for most part of the day.(3) When maize plants were irrigated after grown under deficient soil moisture conditions, leaf senescence delayed and leaf photosynthetic rate was kept high significantly compared with the continuously irrigated plants and the unirrigated plants. Drastic increase of root exudation after the irrigation was observed and the exudation sap contained higher concentration of N, K and other nutrients.(4) The reduction in chlorophyll content and photosynthetic rate of a leaf due to senescence was promoted in maize plants growing under deficient soil moisture conditions. Total amount of cytokinin and nitrogen, transported to shoots from roots decreased in the plants. The infusion of cytokinin into a stem suppressed the reduction in leaf chlorophyll content and photosynthetic rate in the plants under deficient soil moisture conditions. This result indicate that cytokinin transported from roots would be important in keeping leaf chlorophyll content and photosynthetic rate high under deficient soil moisture conditions.

研究大气和土壤湿度条件对根系发育和根功能的影响以及根功能对作物生长和干物质生产的影响，以提高水和肥料的利用效率。获得以下结果：(1)在北海道札幌和加利福尼亚州戴维斯在灌溉和未灌溉条件下种植马铃薯植株，并比较根系发育。与灌溉条件下生长的植物相比，在未灌溉条件下生长的植物根系发育良好。然而，即使在相同的灌溉处理下，戴维斯种植的植物也具有更大且密集的根系。(2)推导出了估算水分利用效率的简单方程。这些可能适用于玉米和棉花冠层，在一天的大部分时间里没有明显的升级。(3)当玉米植株在土壤水分不足的条件下生长后进行灌溉时，与连续灌溉相比，叶片衰老延迟，叶片光合速率显着保持较高水平。灌溉植物和未灌溉植物。灌水后根系分泌物急剧增加，渗出液中含有较高浓度的N、K等养分。(4)缺水条件下生长的玉米植株，促进了叶片因衰老而导致的叶绿素含量和光合速率的降低。土壤湿度条件。植物中从根部运输到芽的细胞分裂素和氮的总量减少。在土壤水分不足的条件下，将细胞分裂素注入茎中可以抑制植物叶片叶绿素含量和光合速率的降低。这一结果表明，在土壤水分不足的条件下，从根部转运的细胞分裂素对于保持叶片叶绿素含量和光合速率较高非常重要。