根域体积对甜瓜幼苗生长及光合特性的影响

Effect of rooting -zone restriction on the growth and photosynthetic characteristics of muskmelon seedling

以厚皮网纹甜瓜皇后做试验材料 ,利用穴孔体积穴盘 ,研究了根域体积对甜瓜幼苗生长及其光合特性的影响。结果表明 ,冬季节能育苗条件下 ,苗龄 <32 d幼苗 ,其单株叶数、叶面积、地上部干物重和叶绿素含量在不同根域限制处理间没有显著差异 ;当苗龄 >32 d,随着根域限制程度的增加 ,37m L和 1 6m L处理幼苗的叶数、叶面积、干物重显著低于 470 m L、1 68m L和 41 m L处理 ,叶绿素含量却表现出相反的变化趋势 ,但上述指标在 37m L和 1 6m L间 ,470 m L、1 68m L和 41 m L处理间差异不显著。在根域体积限制严重时 ,35d幼苗叶片叶绿体超微结构有降解趋势。光合速率日值以根域限制小的幼苗显著高于根域限制程度大的 ,但日峰值却是根域限制严重的 37m L和 1 6m L幼苗出现时间早 ,大约为测定时段的 9:0 0am。

With muskmelon ( Cucumis melo L.cvs) “Huanghou” as the material,the effect of rooting zone restriction on the growth and photosynthetic characters of muskmelon seedling were studied.The results showed that the leaf number and area per plant and chlorophyll concentration were not significant different among treatments for as early as 32 days seedlings raised in autumn and winter with the way of saving energy.But for more than 32 days seedlings,with the rooting zone restriction increasing,the leaf number,area and dry matter of seedlings raised in rooting zone volume 37 mL and 16 mL respectively were less than that of the control,168 mL and 41 mL treatments while chlorophyll concentration was increased as against above 2 indexes.The differences between the 37 mL,16 mL treatments,and among the control,168 mL and 41 mL treatments in above 3 indexes were not presented.In severe restriction,the ultrastructure of chloroplast for seedlings with rooting zone volume 16 mL had the trend of collision.The values of photosynthetic rate in every 2 hours within the whole day were high for treatments with less restriction,but the peak values in a day of 37 mL and 16 mL treatments came early,which was at about 9:00 a.m.during the testing period.