Results of the study of the reaction of cotton descendants to inbreeding

Goal. To study the influence of inbreeding on the uniformity of plants of forced self-pollinated lines and the level of their modification variability. Methods. Field — to establish phenological phases of plant growth and development; measurement and weighing — to record the yield; laboratory — to determine the structure of the yield; mathematical and statistical — to conduct variance analysis and statistical data processing to assess the reliability of the results obtained. Results. It was established that the heterogeneity of varieties in qualitative dominant traits was manifested already in the first two years of self-pollination. In this case, the plants were culled. All inbred lines of the studied cotton varieties mainly retained the typicality of the variety. However, for some quantitative traits, their heterogeneity was higher compared to self-pollinated lines. However, no pattern was found: in one case, the self-pollinated variant had better characteristics, and in the other, the cross-pollinated one. Thus, in the Trakia variety, the self-pollinated specimen had a larger capsule, weighing 5.5 g. A similar picture was observed concerning the length of the fiber in the Natalia variety — 30.0 and 29.5 mm, respectively. However in most cases, plants of self-pollinated varieties and hybrids had better quality indicators. Self-pollinated specimens almost always had a lower coefficient of variation of traits. Conclusions. Given the results of the studies, it can be concluded that significant depression — degeneration or deterioration of characteristics — does not occur in self-pollinated plants. On the contrary, in many cases, such plants have a lower coefficient of variability.