土壤水分对寒地水稻生育特性和物质积累的影响

选用上育397和绥粳3号两个水稻品种,于分蘖期、穗分化期、抽穗后1～10d、抽穗后11～20d分别进行土壤水势为-30～-35kPa和-60～-65kPa的控水处理,研究了土壤水分对寒地水稻的生长发育、物质形成与分配规律的影响。结果表明,分蘖期控水对株高影响不大,土壤水势为-30～-35kPa时,使两个品种的茎数显著减少,上三片叶叶面积不同程度的降低。穗分化期控水使两个品种的株高显著降低,主要是极显著地降低了第二至第四节间的长度;土壤水势为-30～-35kPa时,上三片叶叶面积降低,而两个品种的茎数、穗数却极显著增加。抽穗前土壤水势为-30～-35kPa时,两品种在齐穗期茎、鞘、穗的干重均低于对照,各器官的物质输出率也有所降低,大多数控水强度大的处理降低幅度也大。抽穗初期土壤水势为-30～-35kPa时,上育397多数处理各器官的物质输出率低于对照,而绥粳3号多数处理各器官的物质输出率高于对照。不同水稻品种在不同生育阶段对不同程度水分胁迫反应不同,抽穗前期是水稻的需水敏感期,对水稻的生长发育、物质积累与输出影响最大。

Effect of Soil Moisture on Growth and Dry Matter Accumulation of Rice in Cold Region

To study the effect of soil moisture on growth and dry matter accumulation of rice in cold region,controlling water treatments(CWT) for the two rice varieties(Shangyu 397 and Suijing 3) at-30 to-35 kPa and-60 to-65 kPa of soil water potential were carried out during tillering stage,panicle initiation stage,1-10 days after heading,11-20 days after heading,respectively.When soil water potential(SWP) during tillering stage was kept at-30~-35kPa,the effect on plant height was very little,the culms of the two varieties were decreased apparently,and areas of three leaves from the top in two varieties were reduced differently.While SWP during panicle initiation stage was kept at-30~-35kPa,the height of the two varieties was decreased obviously and its main reason was that the internodes length from the second node to the forth node were decreased significantly,and areas of three leaves from the top in two varieties were reduced,but the culms and panicles per hill of the two varieties were increased significantly.While SWP before heading stage was kept at-30~-35kPa,the stem dry matter weight(SDM),the sheath dry matter weight(SHDM) and the panicle dry matter weight(PDM) of the two varieties during full heading stage were lower than those of CK,and exportation percentage(EP) of dry matter in every organ of two varieties also were reduced and reduced range at-60~-65kPa was greater than that at-30~-35kPa.While SWP during the beginning of heading stage was kept at-30~-35kPa,EP of dry matter in every organ of Shangyu 397 on the numerous tests was lower than that of CK,but Suijing 3 was opposite.The response of growth and development and accumulation of dry matter of different rice varieties is different on the different developing stage under the different treatmens.The effect of soil moisture on growth and dry matter accumulation of rice during tillering stage and panicle initiation stage is more serious than that in other treatments.