The effect of the temperature regime on the manifestation of sterility in the CMS line of sweet pepper

Relevance. Over the years, there has been a growing trend in the production of commercial sweet pepper fruits in Russia, both in protected and open ground. However, the domestic seed industry currently does not produce enough high-quality hybrid sweet pepper seeds. The use of cytoplasmic male sterility F1 hybrids in seed production and hybridization in protected soil conditions makes it possible to increase the profitability of production and produce high-quality seed material. There is a problem when working with some CMS lines: under the influence of poorly controlled environmental factors (in particular, temperature) Such lines can form fertile flowers, self-pollinate and produce offspring with non-standard hybridity, thereby reducing the heterotic potential of the hybrid generation. The purpose of the study. To study the effect of the temperature regime on the manifestation of sterility in the CMS line of sweet pepper, which is unstable for this reason. Materials and Methods. The experiment was conducted in 2024-2025 on the basis of the Department of vegetable growing and the Laboratory of Biotechnology and molecular Biology of the Federal State Budgetary Budgetary Institution "FNC Rice" in an artificial climate chamber with the separation of the studied material into two experimental variants: 1 – night temperature less than 18oС, 2 – night temperature more than 18oС. The research material is a temperature–affected CMS line ms Yant 85. In the experiment, the following calculations and observations were carried out: measuring the length of buds in branching orders in mm with the stage of bud development fixed; visual assessment of the sterility and fertility of flowers by branching order; microscopic analysis of the sterility and fertility of flowers, as the fruits formed and matured, the number of seeds that had set was calculated. Results. The conducted research revealed a tendency of sterility and fertility on the temperature–affected CMS line. Thus, the night temperature of less than 18°C in the first version of the experiment, which persisted throughout the entire flowering in tiers up to the sixth order, affected the formation of fertile flowers, followed by the formation of fruits on parts of the studied plants. In the second version of the experiment, the established night temperature of more than 18oС affected the formation of mostly sterile flowers. Keywords: sweet pepper, first-generation hybrid, seed production, cytoplasmic male sterility, temperature factor, sterility, fertility, artificial climate chamber.