短日照对几种不同光反应型水稻生长发育的影响

以自然日照为对照，在塑料大棚内对比观察了4个不同光反应型水稻品种在生长发育的各阶段对短日照的反应特性。结果表明：早粳晚熟品种、中粳中熟品种在3～4叶龄短日照处理20～30d开始对短日照有反应，主茎叶龄6～7叶时植株对日照长度最敏感，抽穗时间(由播种期到抽穗期的时间)较对照减少约26天；晚熟品种对日照长度反应的时期晚。不同品种的主茎叶片数、株高与抽穗时间成正相关，且达极显著水平，但籼稻品种的相关系数最小。短日照对早粳晚熟品种辽5和中粳中熟品种冀粳8号的穗粒数和结实率的影响很大：在7叶龄5～10d的短日照处理条件下，辽5的穗粒数和结实率与对照相差最小；冀粳8号最适宜的短日处理分别为7叶龄10h短日照处理5～10d，中粳晚熟品种冀糯1号在7叶龄15d的短日照处理条件下，短日照对其穗粒数和结实率的影响最小；6叶龄20d短日照处理对籼稻品种南农大的穗粒数和结实率的影响最小。

Effect of Short-day Sunshine on Development of Several Photosensitive Rice Varieties

In contrast with nature sunshine, reaction of 4 rice varieties to short-day sunshine in 7 development period in the plastic shed was studied comparatively.The results showed that late maturity of early japonica and middle maturity of middle japonica rice varieties started reacting to short-day sunshine twenty or thirty days later in the third or forth blade.The period in sixth or seventh blade was the most sensitive to duration of sunshine.Period of heading (form sowing to heading ) was twenty-six days less than ck.Late maturity varieties reacted on duration of sunshine in later stage, while photosensitivity of indica rice was the weakest.There was significant positive correlation between the number of leaves, plant height and days of heading, but correlation coefficient about indica rice was the lest.Effect of short-day treatment on number of seeds obtained(NSO) and seed set rate(SSR) of liao 5 and jijing 8 was obvious:NSO and SSR of Liao 5 in 7 leaf-age stage for five days short-day treatment were almost equal to ck.NSO and SSR of Jijing 8 were the highest in 7 leaf-age stage for 5 or 10 days.The best period of short-day treatment of jinuo 1 was in 7 leaf-age stage for 15 days. Effect of short-day treatment on NSO and SSR of indica rice was lest in 6 leaf age for 10 days.