The N.I. Vavilov's theory of immunity and current investigations on plant resistance by the example of oats

In light of development of the N.I. Vavilov's theory of immunity the author summarized and analyzed the results of investigations of resistance in variants of oats cultural and wild species of different geographic origin to the most harmful diseases on natural infectious background. The performed complex studies of specific and intraspecific variety of plants of Avena L. genus from VIR collection on resistance to obligate and facultative pathogens have revealed the resistance forms with different ploidy level and ecologo-geographic origin. The obtained data confirm the thesis of N.I. Vavilov that the forms resistant to the pathogens appear only in favorable for infection conditions and are confined to the centers of the most variety of species with the greatest epiphytotic load.