Evaluation of the green pea (Pisum sativum L.) collection for presence of carriers of r and rb mutations

Objective. To evaluate the green pea (Pisum sativum L.) collection in order to identify carriers of r and rb mutations in it. Methods. Pea accessions were grown in the field, and seeds were produced under controlled pollination. The starch granule shape was determined in micrographs taken with a computer digital microscopic camera DMC-300 through a Biolam-15 microscope (object lens × 40). The starch content was determined polarimetrically by the Evers method and the amylase content colorimetrically — by the BO Juliano method. The data were statistically processed using analysis of variance. Results. The effect of r and rb mutations on the starch content and fractional composition in pea seeds was confirmed. In smooth-seed accessions the average starch content was 39,9 %, and the amylose content in starch was 45,9 %, while in r mutation carriers these contents were 31 ,2 % and 67,6 %, respectively, and in rb mutation carriers — 26,9 % and 28,2 %, respectively. An accession with marrowfat seeds, roundish starch granules and a low content of amylose in starch was identified. It was established that this accession was a carrier of a recessive mutation that is not allelic to r mutation and coincides with rb mutation by the effect type. Conclusions. A new genetic source of starchmodifying monogenic rb mutation of pea was identified. It was involved hybridization with sources of r mutation to expand the genetic basis of pea cultivar breeding.Keywords: peas, Pisum sativum, genetic diversity, r, rb, seed phenotype, starch grain shape, starch content, amylose content.