陆地棉基因型间竞争对产量及构成因素的影响

利用陆地棉色素腺体作为指示性状，采用４个遗传差异较大的品种研究了在基因型竞争条件下陆地棉植株性状的变化。结果表明，纯型种植时高产的基因型，在品种混合体中不同基因型竞争下生产力下降，而低产基因型的生产力则有所提高。品种产量越高，由其组成的混合体比预期值减产越多。品种混合体的产量均未超过其组成中的高产品种，多数品种混合体的产量均低于预期值。籽棉产量、皮棉产量、单株结铃数均具有明显的竞争效应和趋势，单铃重、衣分无明显的竞争趋势。

Effect of Competition between Upland Cotton Genotypes on Yield and Its Components

In this investigation,four different varieties and pigment-glandless as a marker were used to study the changes of the plant traits of upland cotton under genotypic competition. The results indicated that the productivity of the genotype,which had the highest yield when planted as a single line, decreased under the genotypic competition in varietal mixture. The yield capacity,however, of the genotype, which yielded lower as single-line planting, increased under such a competition. The higher yield a variety had, the lower the expected yield of the varietal blends consisted of the variety was. Each mixture yielded lower than the component which had the highest yield when planted as a single line. Also, the yield of most blends was lower than the means of its components. The apparent competition effects on seed cotton yield,lint yield and the number of boll per plant were detected. Nevertheless,no apparent competition effect was found in boll weight and lint percentage.