基因型和栽插密度对甘薯农艺性状及结薯习性的影响

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,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.结果表明,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.该试验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.本试验表明,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.

Effects of Genotype and Planting Density on Agronomic Traits and Storage Root of Sweetpotato

The effects of different genotypes and planting densities on main agronomic traits,storage root traits and yield were studied with 6 high-quality sweetpotato varieties as study objects by 2-factor completely random design.The results showed that there were significant differences in stem diameter,length of the longest vine and top/root (T/R) between different genotypes,T/R differed significantly under different planting densities,and number of basal branches decreased with planting density increasing.Genotype and genotype × density showed significant or very significant effects on fresh root yield per plant,dry matter content and fresh root yield per hectare,fresh root yield per plant gradually decreased with planting density increasing,while fresh root yield per hectare increased with planting density increasing.Numbers of storage roots in different sizes of the 6 sweetpotato cultivars all exhibited an order of number of large-sized storage roots＜number of medium-sized storage roots＜small-sized storage root;and there were very significant differences in ratio of large-sized storage roots between different genotypes.The number of largesized storage roots,ratio of large-sized storage roots and number of commercial storage roots deceased with planting density increasing,while there were no significant differences in number of medium-sized storage roots,number of small-sized storage roots,ratio of medium-sized storage roots and ratio of small-sized storage roots between different densities.Correlation analysis showed that there was significant positive correlation between number of basal branches and fresh root yield per plant;dry matter content in storage roots was in significant positive correlation with stem diameter,and in significant negative correlation with length of the longest vine;fresh root yield per hectare was in significant positive correlation with fresh root yield per plant,and in very significant negative correlation with dry matter content;and ratio of large-sized storage roots was in very significant positive correlation with number of large-sized storage root and fresh root yield per plant,and in very significant negative correlation with ratio of medium-sized storage roots and ratio of small-sized storage roots.This experiment showed that under the planting density of 7.5×104 plants/hm2,the 6 sweetpotato cultivars all reached the highest numbers of commercial storage roots and fresh root yields per hectare.