Ecological genetics

The issue No. 3 of the journal “Ecological Genetics” is dedicated to the 135^th anniversary of Academician Nikolai Ivanovich Vavilov, which is celebrated on November 25, 2022. N.I. Vavilov laid the foundations for systematic work with the world collections of cultivated plants and their wild relatives. To carry out large-scale work on the study of plant genetic resources, N.I. Vavilov attracted geneticists, biochemists, and physiologists to the institute he created. A distinctive feature of the extensive large-scale and complex studies of the VIR gene pool were the approaches that allowed generalizations of the observations made in the light of hereditary variability. The fundamental works of Vavilov and his associates in the direction of complex research of cultivated plants allowed to make cardinal transformations in the entire scientific and production chain “collection–prebeeding–beeding–seed production–production”. This issue presents a cross-section of modern works in the field of the study of plant genetic resources, which demonstrates the continuity and development at a new level of the directions founded by N.I. Vavilov and his associates.

BACKGROUND: Significant damage to barley crops in the southern regions of the Russian Federation is caused by the greenbug Schizaphis graminum Rondani. Cultivation of resistant varieties is a cheap, efficient and environmentally friendly way to combat the phytophage. The specificity of relations between S. graminum and barley is shown, that determines the need to broad the genetic diversity of cultivated varieties.

AIM: The study of effectiveness and genetic control of the greenbug resistance in barley accessions from Mongolia.

MATERIALS AND METHODS: We studied 175 barley landraces from Mongolia for resistance to the Krasnodar aphid population. We assessed damage to resistant lines selected from heterogeneous accessions k-3885, k-3904, and k-4080, as well as the variety Post (a carrier of the previously identified Rsg1 gene) by 86 aphid clones isolated from the population. Under laboratory conditions, the aphid resistance segregation of F₂ hybrids was analyzed from crossing three accessions from Mongolia with a susceptible tester.

RESULTS: Five heterogeneous accessions were identified, in which plants with high resistance to the pest were found; in 28 accessions, damage to the leaf surface of the resistant component varied from 31% to 60%. As a result of the assessment of the resistance of four barley accessions to S. graminum clones, 15 virulence phenotypes were identified. Accessions k-3885, k-3904 and k-4080 each have one dominant resistance allele, which differ from each other and differ from Rsg1.

CONCLUSIONS: The genetic diversity of barley accessions from Mongolia in terms of greenbug resistance is low. The genotypes of S. graminum differentially interact not only with the major, but also with weakly manifested barley resistance genes.

BACKGROUND: Studies were carried out on the creation of haploinductor lines using various methods for testing haploinductor and marker ability from the VIR maize genetic collection, adapted to the conditions of the Liaoning province in China and the South of Russia.

MATERIALS AND METHODS: On 22 maize testers, studies were carried out on the creation of haploinductor lines and testing the haploinductor and marker ability by the test-cross method. Sources of R1-nj, B1, Pl1 genes from the VIR maize genetic collection were used.

RESULTS: The lines of maize haploinducers Liaoyu No. 1, Liaoyu No. 2, Liaoyu No. 3 and Liaoyu No. 4 were created with a haploinduction frequency of 6.85%, 7.53%, 6.66% and 6.03%. respectively, with a high quality of labeling with the R1-nj, B1, Pl1 genes in test crosses.

CONCLUSIONS: In the process of selection of haploid maize on the basis of genes A, haploinductor lines with a high frequency of haploinduction and high efficiency of markers in test crosses, abundant pollen and grain productivity, resistance to late blight and lodging, and adaptation to the agroclimatic zone of Shenyang Province (China) were obtained and the North Caucasian Federal District (Russia).

Vigna unguiculata (cowpea) is a species widely cultivated in southern countries, it occupies the third place in the world in terms of cultivation area among leguminous crops. Cowpea is distinguished by its resistance to drought and infertile lands, productivity, nutritional value and excellent culinary qualities of pods and seeds. In recent years interest in vegetable varieties of cowpea has increased in Russia. It is necessary the creation of new varieties that adapted to cultivation in different regions and suitable for mechanized cultivation. The type of stem growth habit is one of important signs in the selection of modern cowpea varieties. Knowledge of variability and stability of this feature and its interrelationships with other morphological features is necessary for the effective implementation of culture breeding programs.

4 cowpea samples with different growth types were the material in this study. The plants were grown in contrast air humidity conditions — at 60% and 90%. At total 14 morphological features were analyzed in 110 plants. The analysis revealed the significant influence of air humidity on the variability of the length and width of the first leaf. It was shown influence of humidity on the ability of plants to form a climbing shoot. The variability of length of the second internode, the pod length and the width of the middle leaflet was depended on the individual characteristics of the genotype. The variation in plant length was due to a complex of factors and it was interrelated with growth conditions and genotypic characteristics. In addition, an unidentifiable effect of air humidity on the growth habit type of different samples was revealed.