Xenia effect on seed and embryo size in cotton (Gossypium hirsutum L.).

The term xenia was coined to describe the effect of foreign pollen on the development and characters of the seed. To study its importance and consequences for various seed traits in cotton (Gossypium hirsutum L.), the effect of pollen genotype on seed and embryo weight was studied with seeds from 15 F1 hybrids. Cross-fertilization changed seed weight by up to 7.0% in relation to self-fertilization. Xenia effect significantly increased embryo weight of cross-fertilized seeds, by up to 14.4% in comparison to self-fertilized seeds. Seeds of some crosses had a lower hull content than corresponding selfed seeds. On average, the xenia effect was greater for embryo weight than for seed weight. However, in some crosses there was no difference between cross- and self-fertilized seeds for seed weight, embryo weight, moisture content and hull content. Positive xenia effects for seed weight and embryo weight may help us to establish uniform stands of vigorous hybrid seedlings, especially under unfavourable conditions. Also, larger seed and embryo weight, along with lower hull content, could result in higher oil yield. Therefore, careful choosing of genotypes as parents and of cross direction in the production of hybrid seed is very important in cotton.