不同种植密度对四川攀西桑叶片光合日变化的影响研究

选用南叶1号桑树品种,针对不同种植密度对不同叶位叶片的光合作用及同化物的积累影响开展研究。试验表明,桑树叶片的净光合速率及碳水化合物积累等特性与种植密度关系密切。较低的种植密度能减少桑树叶片净光合速率的下降,延缓桑叶光合能力的减退,延长桑树同化产物积累的时间;较高的种植密度能在一定程度上减弱＂午休＂现象。四种设定密度比较,以21000株/hm2的密度的中位叶日光合总量最高,光合产物的积累最大。

Effects of Planting Density on Photosynthetic Diurnal Changes of Mulberry Leaves in Panxi Region of Sichuan Province

Nanye-1 mulberry variety was selected to study the effects of planting density on the photosynthesis and assimilate of its different leaf areas. The result shows that,during its mature period,the mulberry leaf＇s net photosynthetic rate and carbohydrate accumulation are strongly correlated with the planting density. A lower planting density can slow down the decrease of mulberry leaf＇s net photosynthetic rate,delay the decline of mulberry leaf＇s photosynthetic function and prolong the accumulating time of the plant＇s assimilate. A higher planting density can reduce the extent of ＇noontime rest＇ of the leaves in the middle section of the plant. At the planting density of 21,000 plants / hm2,the leaves in the plant ＇s middle section enjoy a larger photosynthetic amount,a higher level of photosynthetic product accumulation.