Principles of rye breeding for low content of water-soluble pentosans in grain

Abstract

Winter rye is the second cereal crop after wheat. Rye exceeds other cereals in terms of nutritional value due to the high content of lysine, methionine, valine, as well as the balance of other essential amino acids in its protein. The direct use of baking rye grain as an animal feed is limited by the presence of water-soluble pentosans (arabinoxylans) in it. Therefore, the creation of low-pentosan rye with highly nutritious grain is a very perspective direction in the grain feed cultivar breeding. Under the leadership and with direct participation of Vladimir D. Kobylyansky, a technology for breeding multiple-use low-pentosan rye was worked out at the N.I. Vavilov VIR in 2004-2021. A relationship between the low pentosan content and grain coat thinness has been revealed. For the first time, an effective method of low-pentosan genotypes identification by selecting thin-coat grains has been developed. This method was used to study 562 accessions from the VIR collection represented by cultivar populations, weedy and wild rye. It has been established that the number of thin-coat grains in a sample varies from 12 to 70%, depending on the accession. Varieties with the highest frequencies of low-pentosan genotypes can be used as initial material for breeding. The dependence of low content of water-soluble pentosans in grains on the expression of recessive alleles of the gene/genes responsible for the manifestation of the trait has been revealed. To create grain feed cultivars, it is proposed to use the method of cumulative intrapopulation crosses and the method of pairwise cross-pollinations of the plants with indicator ears. As a result, new cultivar populations of low-pentosan rye for universal use have been created, namely ‘Vavilovskayaʼ, ‘Bereginyaʼ, ‘Podarokʼ, ‘Yantarnayaʼ, ‘Krasnoyarskaya Universalnayaʼ, ‘Novaya Eraʼ, and ‘Argaʼ. These cultivars are characterized by a low, as in wheat, genetically determined content of pentosans. They have been evaluated in the main rye growing regions, tested as raw material for fodder production and bread baking, and found to match the previously released commercial (bread) cultivars in terms of yield. The baking properties of new cultivars do not exceed those of bread rye. The use of low-pentosan cultivars in animal diets eliminates the problem that exists when feeding them with bread rye grain. These cultivars have no analogs in the world; they are listed in the State Register for Selection Achievements Admitted for Usage (2023).