基因型和栽插密度对甘薯农艺性状及结薯习性的影响

摘要

[目的]探讨不同基因型和栽插密度对甘薯主要农艺性状、结薯性及产量的影响.[方法]以6个优质食用甘薯品种为研究对象,采用两因素完全随机设计方法.[结果]茎粗、最长蔓长和蔓薯比(T/R)在不同基因型间差异显著,T/R在不同栽插密度下差异显著,基部分枝随栽插密度增高而降低.单株鲜薯重、薯块烘干率和单位面积鲜薯产量等产量性状,在基因型、基因型×密度间均表现出显著或极显著差异,单位鲜薯重随栽插密度增加逐渐降低,单位面积鲜薯产量则随栽插密度升高而增加.本试验6个甘薯品种的结薯性均表现出大薯数＜中薯数＜小薯数,且不同基因型大薯率呈极显著差异;大薯和商品薯数、大薯率随栽插密度的升高而降低,中、小薯数,中、小薯率在不同栽插密度间无显著差异.相关性分析表明,基部分枝和单株鲜薯重呈显著正相关;薯块烘干率与茎粗呈显著正相关,与最长蔓长呈显著负相关;单位面积鲜薯产量与单株鲜薯重呈显著正相关,与烘干率成显著负相关;大薯率与大薯数、单株鲜薯重呈极显著正相关,与中、小薯率呈极显著负相关.[结论]栽插密度为7.5×104株/hm2,6个甘薯品种的商品薯数和单位面积鲜薯产量均达最高.%[Objective] Effects of different genotypes and planting densities on the agronomic traits and storage root of sweetpotato were studied.[Method]Taken 6 cultivars as tested materials,completely random design of 2 factors was applied.[Result] The stem diameter,the longest vine and Top/Root value (T/R) were significandy different between different genotypes,and T/R value also showed significant difference in different planting density,the branches decreased with the increase of planting density.The fresh root yield per plant,average dry matter content and fresh root yield per hectare were significantly or very significantly different in genotype and genotype × density.Fresh root weight per plant decreased with the increase of planting density,while the fresh root yield per hectare increased with the increase of planting density.The results of 6 cuhivars showed the number of big-sized storage roots ＜ number of medium-sized storage roots ＜ number of small-sized storage roots,and the ratio of big-sized storage roots showed extremely significant difference in different cuhivars.The ratio of big-sized storage roots decreased with the increase of planting density,while there was no significant difference of medium-sized and small-sized storage roots ratio in different planting density.The number of branches had a significantly positive correlation with fresh root yield per plant,the dry matter content was significantly positively correlated with stem diameter,and negatively correlated with the longest vine.The fresh root yield per hectare was significantly positively correlated with fresh root weight per plant,and negatively correlated with dry matter content.The ratio of big-sized storage roots was significantly positively correlated with fresh root weight per plant,and negatively correlated with medium-sized and small-sized storage roots rate.[Conclusion] In this research,both the commercial root number and yield were the highest when the planting density was 7.5 × 10 4 plants/hm2,which was applicable to all of the 6 cultivars.