THE USE OF CLUSTER ANALYSIS IN THE SELECTION OF SORGHUM × DRUMMONDII

The main purpose of cluster analysis is to divide the set of objects under study characterized by a set of features into groups(clusters) that are homogeneous in the appropriate sense. A positive feature of cluster analysis is the ability to compress a largeamount of information, systematize it, build a scientifically based classification, identify the internal relationship between theunits of the population under study. The aim of the article is to identify promising samples of sorghum × drummondii accordingto the main economic characteristics based on cluster analysis for further use in breeding for heterosis in the conditions of SaratovOblast. Grouping of samples allows for examining the composition of each cluster as fairly identical source material in terms ofthe severity of the indicators. During the period from 2015 to 2017, 32 samples of sorghum × drummondii were evaluatedaccording to 12 economically valuable characteristics, which were subjected to statistical processing. At the 22nd iteration stepwith a Euclidean distance of 14.4, the samples were grouped into 10 clusters. Cluster differences were observed to be significant,except for the "1,000 Seed Weight" feature. The study distinguished clusters 1 and 5 based on the intensity of the initial growth.The second cluster is characterized by the number of differences in the parameters of the largest leaf, the width of the flag leaf,and grain yield. Clusters 3 and 4 did not differ significantly in most features. In the 6th cluster, differences were noted accordingto the following indicators: "the extension of the panicle leg", "height at maturity", "inflorescence length" and "length of the flagleaf". The 7th cluster revealed differences in the width of the flag leaf, the width of the inflorescence, and grain yield. The 8thcluster distinguished itself by the parameters of the flag leaf and the yield of green biomass. In the 9th cluster, differences wererevealed on the basis of: "height at maturity" and the parameters of "inflorescence", "largest leaf". The last cluster wasdistinguished by the greatest number of differences in the parameters of the largest leaf (in length 8 and 6 in width), grain yieldand green biomass, the extension of the panicle leg. The results obtained are used in the selection of components of crosses inthe selection of grass sorghum hybrids.