Screening of rice gene pool for resistance to pyriculariosis by phenotyping and DNA genotyping

Abstract

When creating new resistant varieties of rice of an intensive type, an important aspect of the breeding process is the study of the diversity of cultural genetic resources. In the Krasnodar Territory, in Russia and in the world as a whole, the most harmful and common rice disease is pyricularosis (Pyricularia oryzae Br.et Cav.). The aim of this work was to study the genetic diversity accumulated in the collection of the rice institute (ARRRI, Krasnodar city) for the resistance to the causative agent of pyriculariosis to create a new source material with genes for a wide spectrum of resistance. In the course of studies, the results of phenotypic (1337 samples), immunological (775 samples) and molecular screening (115 samples) of the gene pool of Oryza sativa L. were obtained for the resistance to the pathogen of pyriculariosis. The rate of development of the disease (RDD,%) over the years of testing the general plasma varied within 5.6-85.0%. The proportion of varieties medium resistant to the fungus M. Grisea was significantly higher in almost all countries except Italy and Brazil, where the number of resistant forms was at the level of medium resistant. In the general plasma of Bulgaria, Uruguay, Greece, India and African countries, stable forms were generally absent. The world variety of rice genotypes showing resistance to the local pathogen population has been shown. Screening of the rice gene pool for the presence of the Pi-9 and Pi-k genes made it possible not only to identify carrier donors, but also to establish their frequency of occurrence in the global general plasma. Against a provocative background, the identification of effective resistance genes was carried out using monogenic differentiator lines of Pyricularia oryzae races, 15 resistance genes were isolated.

Development of rice pre-breeding resources with blast resistance

“…One of the strategies for developing stable blast resistance is combining several resistance genes in the genotype. A number of successful breeding programs have been carried out to develop blast-resistant rice varieties by gene pyramiding using marker breeding [5][6][7][8]. An important resource for accelerated genetic stabilization of the obtained breeding material is experimental haploidy [9][10][11][12][13].…”