不同密度地膜甜菜光合与呼吸特性及与产质量间的关系

本文探讨了不同密度群体结构下，地膜甜菜光合及呼吸作用的日变化、生育中后期光合、呼吸作用的变化及与产量和经济性状间的相关性。结果表明：低到中等密度下（４５０００～７５０００株／ｈｍ２）群体光合、呼吸作用日变化为双峰曲线，高密度下（１０５０００株／ｈｍ２）为单峰曲线。中密度至高密度下，群体表观光合强度和呼吸强度日变化均为单峰曲线。密度越大，随生育期推进，表观光合强度下降越明显，而净光合强度则大幅度降低。相关分析表明，地膜甜菜群体光合、呼吸作用与甜菜个体生长相关性较好，而与含糖率、产糖量间相关性较差，与地上部生长相关性较好，而与根部生长相关性较差。

Characteristics of Photosynthesis and Respiration in DifferentSugarbeet Population Covered with Plastic Film and theCorrelation between Yield and Quality

Diurnal change and variation in the mild and later growth period of net photosynthesis rate(NPn),respiration rate(Rs)and apparent photosynthesis(Pn)of different population in sugarbeet which covered with plastic film and the correlation between yield and quality were studied in this paper.The results indicated that the diurnal change of NPn and Rs appeared to be two peak curve in 45000 plants/hm2 and 75000 plants/hm2,but its a single peak curve in 105000 plants/hm2. With the growth period pushed on, NPn,Pn and Rs decreased. The decline of Pn is higher which in high population whereas NPn decreased large-scalely.The correlation analysis showed that Pn and Rs in different population is better correlated with individual sugarbeet but have lower coefficient index with sugar content and sugar yield,meanwhile,they were better correlated with the growth of tops and have coefficient index with underground part of sugarbeet.