Genotypic diversity and live weight in the populations of the Chukchi breed reindeer

Abstract

Purpose: study of associations of live weight and genotypic traits in reindeer populations.Materials and methods. The studies were carried out in 2018-2020. on the basis of 8 agricultural enterprises in Chukotka. Tissue samples (ear pinch) of deer of different sex and age groups served as material for genetic studies. In molecular genetic studies, 1002 samples were used. Individual genotyping of animals was carried out using the ISSR-PCR method. The live weight of the reindeer was determined using the materials of the zootechnical reports of the reindeer farms. Associations of the average population indices of genetic diversity and live weight of deer were established by a calculation-statistical method of comparing the values of values. The correlation coefficient was calculated by the product method according to the Pearson formula.Results. The variability of ISSR markers in populations indicates a significant similarity between them in most of the allelic frequencies, which confirms the common origin, economic and breeding use of the Chukchi breed deer. The populations are characterized by a high degree of heterogeneity. Differences in live weight between highly productive and less productive populations on average for all sex and age groups of deer amounted to 16.8%. At the same time, the populations with a high live weight of deer significantly exceeded the populations with a lower live weight in the average number of alleles per locus by 5.0% (P <0.01), the number of effective effective alleles - by 11.8% (P <0.001), polymorphic information content index (PIC) - by 35.8% (P <0.01). The homozygosity coefficient in the low-productive animals was 12.6% higher than in the high-productive group. In the populations with the highest live weight of deer - WZR, WAE and AMG, the most significant indicators of genetic diversity were also found: the average number of alleles per locus is 8.57; 10.45 and 8.71; effective alleles per locus - 7.57; 9.10 & 8.15; expected heterozygosity - 0.868; 0.890 & 0.877; PIC index - 0.248; 0.380 and 0.374, respectively. In populations with a low live weight of deer - OST and CHN, the smallest values of the number of active effective alleles per locus were found - 6.68 and 6.41; expected heterozygosity - 0.850 and 0.844, PIC index (proportion of heterozygotes) - 0.151 and 0.254. The correlation coefficient between the indicator of live weight and the genetic diversity of deer turned out to be equal for the average number of alleles per locus r = 0.335; the number of effective alleles - r = 0.52; heterozygosity - r = 0.558, the proportion of heterozygous variants - r = 0.646.Conclusion. The data obtained make it possible to state the existence of a dependence of the live weight of deer on the genotypic diversity in the populations of the Chukchi breed.