源库比改变对白首乌产量形成的影响

目的:研究人为改变白首乌源库比后对产量、干物质积累及相关生理指标的影响。方法:以白首乌为材料,在生育期内人工摘除花蕾、果实或摘除主茎分枝,以不进行处理的为对照,测定不同处理和时期的叶面积系数,叶片叶绿素含量及单叶净光合速率,干物质积累等指标。结果:在处理后前期,摘除主茎分枝虽然对叶片减少有补偿效应,单叶光合速率上升,但叶面积系数小,功能叶负荷大,叶绿素降解快,有早衰现象,物质积累低于对照。摘除花蕾和果实处理单叶光合速率与对照相比虽有降低,但叶绿素含量高,降解速度慢,明显延缓了植株衰老,并且叶面积系数一直处于较高水平,光合产物供应充足,干物质积累量以及对根部的分配显著高于对照和摘除侧枝处理,所以该处理产量显著高于其他处理。结论:摘除白首乌花蕾能增加叶面积系数,减缓叶片叶绿素降解,延长绿叶功能期,从而可以提高干物质积累和运往根部比例,提高产量和效益。

Effect of source-sink ratio changing on yield formation of Cynanchum bungei

Objective: To study the effect of changing source-sink ratio on dry matter accumulation yield,distribution and interrelated physiological index of Cynanchum bungei. Method: Bud,fruit or side tress of C.bungei were picked artificially in the development stage.LAI,chlorophyll content, photosynthesis of single leaf,accumulation and distribution of dry matter at different and treatments were measured.The untreated plant was used as the control. Result: Although leaf decrease can be compensated by the increasing photosynthesis rate of single leaf,the LAI was small,chlorophyll decomposes quickly and these leaves showed the signs of early ageing.The matter accumulation was lower than that of control.Picking bud and fruit made photosynthesis rate of single leaf descend,chlorophyll decomposes slowly and its content keeps high,that inhibited ageing of the plant obviously.The LAI keeps larger,photosynthate was abundant.Dry matter accumulation and distribution to the root were higher than that of control and that of side tress picked.So,the yield with this treatment increased. Conclusion: picking bud can increase LAI,postpone the decomposition of chlorophyll,and protract the functional leaves.Consequently, picking bud can add the accumulation of dry matter,increase proportion to radix and improve the yield and economy benefit.