Features of the photosynthetic apparatus of chlorophyll-deficient mutants of various types and their impact on productivity traits in linseed

The unique phenotypic expression and diverse changes in chlorophyll-deficient mutants make them ideal model objects for physiological, biochemical, and genetic studies, particularly in the context of photosynthesis in various cultivated plants. The paper presents the results of a comparative study of two chlorophyll-deficient mutations of linseed types, chlorina and xantha, obtained from gamma irradiation of seeds and their initial genotypes. It was found that in the xantha type mutation, the disorders affected the morphology of chloroplasts, causing their elongation and, as a result, a change in shape from oval to cylindrical. A decrease in the content of both chlorophylls, especially chlorophyll b, was noted. The carotenoid amount also decreased significantly, although it exceeded chlorophyll b's content. Such changes led to a significant decrease in the growth of dry biomass of plants, a decrease in the photosynthetic potential and the net productivity of photosynthesis. It was established that in the chlorina type mutation, the disorders caused some elongation of chloroplasts, which did not cause a change in their shape. A decrease in chlorophyll a and b content by 30 and 45%, respectively, were noted. The content of carotenoids decreased slightly, corresponding to the level of chlorophyll b. These changes did not lead to a decrease in the photosynthetic potential and the net productivity of photosynthesis. Based on the mutant sample of chlorina, the highly productive variety Zolotistyi was created by the direct selection method, which, in terms of productivity, oil content and yield of oil per hectare, is not inferior to the original line K-7487.