ПРИЗНАКИ БОЛЕЗНЕУСТОЙЧИВОСТИ К ПИРИКУЛЯРИОЗУ В КАЛЛУСНОЙ КУЛЬТУРЕ РИСА

Исследованы каллусные культуры, полученные от разных по устойчивости к пирикуляриозу сортов риса (Oryza sativa L.), и разные по вируллентности штаммы возбудителя пирикуляриоза (гриб Magnaniporthe grisea). Установлено, что некротическая реакция на элиситор гриба (выражавшаяся в побурении клеток) свойственна только каллусам устойчивых, но не восприимчивых сортов риса. Однако не все устойчивые клетки в культуре реагируют некротизацией при обработке элиситором патогена, и поэтому такая реакция не всегда может служить признаком болезнеустойчивости. Таким признаком, по-видимому, может служить образование воздушных гиф гриба в двойной культуре с каллусами риса: растительные клетки восприимчивых, но не устойчивых сортов стимулировали этот процесс.

TRAITS OF VARIETAL RESISTANCE TO BLAST DISEASE IN RICE CALLUS CULTURE

Agrobiotechnology methods offer the rare opportunity of producing unlimited numbers of agrononiically important traits through somaclonal variation, induced mutagenesis, and gene transfer techniques (2, 5, 6). However, it is extremely difficult to detect in vitro cell lines with the required traits. This is because, disease resistance of cell lines docs not have the characteristic phenotypic symptoms in in vitro conditions. Hence the need to search for disease resistance traits in callus culture that reflect the properties of intact plants. It is known that necrotic lesions are formed on leaves of rice plants during infection by incompatible strains of blast fungus (Magnaniporthe grisea), or in response to treatments with the fungal elicitor (7). In this report, we have observed similar response by cultured cells of rice. However, necrotic reation is probably not a reliable trait for screemg rice cells in vitro for blast resistance since some resistant calli do not show such a reaction. It has been shown, that the mechanism of rice plant resistance to blast disease is not restricted to necrotic response, but also involve the production of fungitoxic substances that inhibit the development of fungal spore (1). We have demonstrated in this report that in dual culture with blast fungus, rice calli, depending on compatibility/incompatibility of the interaction, affect the development of the fungus. The growth of fungal colony and the formation of aerial hyphae are stimulated in dual culture with susceptible, but not resistant calli. The fungus colonises the calli of susceptible but not resistant ricc varieties during dual culture. Consequently, the growth and development of blast fungus in dual culture with ricc calli might be used as reliable traits to screen for blast reistance in rice callus culture.