马铃薯4X—2X选系在不同密度下产量及产量性状的表现

本试验采用裂区试验设计。以品种（系）为主区因素、密度为副区因素，研究７个４Ｘ—２Ｘ选系（Ａ１～Ａ７）及其４Ｘ亲本东衣３０３（Ａ８）以及密度（Ｂ１～Ｂ３）对产量和产量性状的影响。品种（系）间在小区总量、小区块茎数、小区商品薯重、小区商品薯数方面差异极显著。Ａ６品系小区块茎数极显著的低于东农３０３，但小区总产、小区商品薯重、小区商品薯数和东农３０３差异没有达到极显著水平．不同密度对小区总产和小区块茎数的影响分别达到了显著和极显著的水平，但对小区商品薯重和小区商品薯数没有显著的影响。较高密度下（Ｂ１，株距３０ｃｍ）小区总产和小区块茎数极显著高于Ｂ２（株距３５ｃｍ）和Ｂ３（株距４０ｃｍ）。在小区块茎数方面，品种（系）×密度互作显著。

THE PERFORMANCE OF YIELD AND YIELD COMPONENTS OF 4X─2X SELECTIONS AT DIFFERENT LEVELS OF DENSITY

In a split-plot design, cultivar(clonc)factor was assigned to the main plot and density factor to the subplot to investigate the influence or 7 4x-2x selections(A1-A7)and their 4x parent cv.NEA 303(A8),and 3 levels of density(B1￣B3)on yield and yield components.The analysis.of variance shown a highly significant difference among cultivar(clones)for total yield,tuber number,marketable tuber yield and marketable tuber number based.on a plot average.The elope A6 was highly significant lower than its 4x parent cv.NEA303 far tuber number,but there was no highly significant difrerence betwcen A6 and NEA303 for total yield,marketable tuber yield and marketable tuber number.The density influenced total yield and tuber number significantly at the level or 0.05 and 0.01,respcetively,but had no effect on marketable tuber yield and marketable tuber number.Higher level of density (B1,70cm betwcen rows and 30cm in the row)was higher than the densigy B2 and B3 for total yield and tuber number at the significance of 0.01 level.Cultivar×density interaction effect was significant for tuber number.