不同栽培密度下白首乌干物质积累和分配规律的研究

目的了解栽培密度对白首乌块根产量和品质的影响,确定其最适合栽培密度。方法在大田条件下,探讨不同栽培密度(A60000、B90000、C120000、D150000株/hm2)与白首乌的光合特性、干物质积累分配、产量及活性成分量之间的关系。结果4种栽培密度下白首乌个体块根干物质积累动态的拟合均呈Logistic曲线变化。不同密度处理单株块根干质量增加速率为A>B>C>D,而单位面积块根干质量增加速率C>D>B>A。处理D的光合速率在块根膨大关键时期显著低于其他各处理,可能是处理D个体块根产量低的原因。密度对块根中部分有效成分的量也有显著影响,其中多糖和黄酮量随密度的增加而增加,但C21甾苷量与密度无显著关系。结论密度对白首乌产量性状影响较大,但在群体和个体上表现不同,与个体块根产量呈负相关,与群体根的生物产量呈正相关。综合考虑块根产量与活性成分量两个方面,处理C为最佳种植密度。

Effect of various planting densities on accumulation and distribution of Cynanchum bungei dry matter

Objective In order to find out the effect of planting density on the yield and quality and determine the optimal planting density for Cynanchum bungei root tuber. Methods Under the condition of field outside, to discuss the relationship between planting density (A: 60 000; B 90 000; C 120 000; D 150 000 plants/hm~2) and C. bungei root tuber yield, accumulation, and distribution of dry matter, effective components, and its characteristic of photosynthesis, relatively. Results Dry matter accumulation of single root tuber accorded with logistic curve under the conditions of four treatments. The accumulative rate of single root tuber is A>B>C>D among different treatments. However, the accumulative rate of colony yield is C>D>B>A. At root tuber thickening stage photosynthesis of treatment D is distinctly lower than other treatments, which was the main reason of the low yield of D treatment perhaps. Density also has effect on effective components, which related with polysaccharides and flavonoids positively and had no notable relation with C_ 21 steroid glycosides. Conclusion Density has great effect on yield of root tuber, but its exhibition on colony and individual plant is different. It was shown that there was a negative correlation between the individual yield and density, while a positive correlation between the colony yield and density. According to the dry weight of root tuber and effective components content, treatment C is the best planting density.