旱作水稻幼穗发育期若干生理特性及节水机理的研究

Studies on the Physiological Characteristics and Water-saving Mechanism at Pregnancy Stage of Dry Cultivation Rice

(常规水作 )净光合速率 (Pn)和蒸腾速率 (Tr)的日变化呈单峰曲线 ;旱作水稻在雨后高土壤湿度时 (覆膜旱作 )和 (露地旱作 )的 Pn 为单峰曲线 ,Tr 为单峰曲线 , 为双峰曲线 ,PFD为光合作用主要限制因子 ;在持续干旱低土壤含水量时 , 和 的 Pn 和 Tr均为双峰曲线 ,气孔导度 (Gs)不同土壤含水量时均为单峰曲线 ,Tr日均值不同土壤含水量时均为 > > ;Gs 日均值均为 < 。 WU E(Pn/Tr)均为 > > ,旱作水稻水分利用率较常规水作高。不同土壤含水量下 , 与 或 之间的日平均 Pn、叶绿素含量 (Ch1)和叶片呼吸强度差异不显著 ,根系呼吸强度 > > 。

The diurnal fluctuation of P n and T r under Ⅰ(normal paddy field) was single peak curve, the P n of Ⅱ(dry cultivation with plastic film mulching) and Ⅲ(unmulching dry cultivation) and the T r of Ⅲ was single peak curve under saturated soil moisture, the T r of Ⅱ was double peak curves, PFD was the main confined factor of photosynthesis under this condition; the P n and T r of Ⅱ and Ⅲ were double peak curves under lower soil moisture. The strong PFD had negative effect on P n, there was no significant difference of P n mean values and the chlorophyll content at different soil moisture by LSR test among Ⅱ, Ⅲ and Ⅰ. The WUE of dry cultivation was higher than that of paddy field, the WUE under different soil moisture was all as following: Ⅱ>Ⅲ>Ⅰ. There was no significant difference of leaf respiration rate between Ⅰ, Ⅱ and Ⅲ; the order of root respiration rate was: Ⅱ>Ⅲ>Ⅰ, showing very significant difference.