种植密度对棉籽生物量和脂肪与蛋白质含量的影响

Effects of Plant Densities on Cottonseed Biomass, Fat and Protein Contents

以科棉1号和美棉33B为材料,2008年在江苏南京(118o50′E,32o02′N,长江流域下游棉区)和河南安阳(114°13′E,36°04′N,黄河流域黄淮棉区)设置密度试验,研究种植密度对棉籽生物量和脂肪与蛋白质含量的影响。结果表明,不同种植密度条件下,棉籽生物量和脂肪含量的变化过程均符合Logistic生长曲线。随种植密度的增大,籽指和脂肪含量降低,且存在显著的线性负相关关系。而各密度处理棉籽蛋白质含量的变化过程均近似于V字型,随种植密度的增大,棉籽蛋白质含量呈开口向下的抛物线变化趋势,南京、安阳试点分别以每公顷3.3和5.1万株密度处理的棉籽蛋白质含量最高。品种、生态点和开花期对棉籽生物量和脂肪与蛋白质含量的形成动态及其对种植密度的响应趋势没有明显影响。不同种植密度对棉籽生物量和脂肪与蛋白质含量的影响与群体冠层光照条件变化密切相关。稀植强光有利于提高棉籽生物量和脂肪含量,而过高和过低密度均不利于棉籽蛋白质的合成与累积。

Two cotton cultivars（Kemian 1 and NuCOTN） were used in the field experiments in Nanjing（118o50′E,32o02′N,Middle Lower Reaches of Yangtze River Valley） and Anyang（114°13′E,36°04′N,Yellow River Valley）.The results showed that under the different plant densities,the cumulative process of cottonseed biomass and fat content met Logistic growth curve.As the plant densities increased,cottonseed biomass and fat content decreased and were strongly negatively correlated with plant densities at both experimental sites and flowering dates.However,the curve of cumulative process of cottonseed protein content was similar to ＂V＂ for each treatment.A highly significant quadratic relationship existed between cottonseed protein content and plant densities for varieties,sites,and flowering dates.The highest cottonseed protein content was obtained under 3.3×105 plants ha-1 in Nanjing and 5.1×105 plants ha-1 in Anyang,respectively.Variety,site,and flowering date had no significant effects on the dynamic changes of cottonseed biomass,fat and protein contents.The impacts of plant densities on cottonseed quality were closely related to canopy light conditions.Low plant densities helped the improvement of cottonseed biomass and fat content,while the too high or too low plant densities were not conducive to cottonseed protein synthesis and accumulation.