Germ and seed morphometric parameters of seeds of vegetable plants of the Umbelliferae family as a breeding subject

Abstract

The work is devoted to the study of statistical parameters of the linear dimensions of the seed, endosperm and embryo, variability, correlations, and the manifestation of these traits in hybrid combinations. Morphometric parameters largely determine the quality of seeds. The presence of an underdeveloped embryo determines the duration of the period of heterotrophic development of the seedling, affects germination, energy, longevity, seed response to changes in germination conditions, and, ultimately, increases the interphase period from sowing to germination. The article shows the high variability of these parameters in numerous representatives of vegetable crops - representatives of the Umbelliferae (Apiaceae) family, analyzes the causes that cause them, and predicts the potential use of this variability in breeding programs. The object of research was the seeds of various varieties of carrots, parsley, parsnips, celery, dill. Measurement of the length of the seed and endosperm was carried out using a caliper. The length of the embryo was determined using a microscope and a video eyepiece at ×40 magnification using the Scope Photo program. The experiment was repeated four times, in each repetition at least 20 seeds. The values of the coefficient of variation in the length of the endosperm and seed varied from 9 to 19%, depending on the species and cultivar characteristics. The variability of the embryo reached 18-28%. between the size of the embryo on the one hand and the length of the endosperm (0.208-0.369) and seed (0.213-0.376) on the other, weak correlations were noted, indicating the independent inheritance of these parameters. The hereditary conditionality of the variability of the embryo, endosperm and seed of carrots (50.8-86.5%) and parsnips (49.6-58.9%) is shown, which characterizes the real possibility of their breeding improvement. In the process of studying distant hybrids of carrots (the parental forms of which differed sharply in morphometric parameters of seeds), it was found that F1 hybrids for these traits predominantly showed positive overdominance (38.1%) and dominance (16.7%). According to the complex of relative parameters (indices), negative overdominance (23.8%) and dominance (4.8%) were more often noted. The results of many years of research indicate that the morphometric parameters (length of the seed, endosperm, embryo) and their ratios (indices) of seeds, like any other biological traits, are genetically determined and depend on species and cultivar characteristics. A comparison of wild-growing and varietal samples of carrots indicates that in the process of cultivation, the size of the embryo underwent significant upward changes, even in the absence of targeted selection. Therefore, when applying artificial selection in this direction, one can expect more significant results.