Every year, many Russian potato growers lose part of their harvest due to late blight.
The causative agent of late blight has a very high genetic variability, which allows it to constantly evolve and quickly overcome single resistance genes. A group of scientists from the All-Russian Institute of Plant Genetic Resources. N.I. Vavilov (VIR; St. Petersburg) and the All-Russian Research Institute of Agricultural Biotechnology (VNIISB; Moscow) and Phytopathology (VNIIF; Moscow Region) reported promising potato hybrids that have a “pyramid” of five to six resistance genes in one plant, and can become the basis of new varieties with long-term resistance to late blight. The article was published in the journal Agronomy.
The hybrids described in this article have been highly resistant to late blight for over ten years when tested under conditions that are most favorable for the development of the disease.
“Russian researchers have made significant progress towards creating potato varieties suitable for cultivation in the system of environmentally friendly potato growing,” comments the head of the Department of Potato Genetic Resources at VIR named after V.I. N.I. Vavilova Elena Rogozina. “The introduction of varieties based on hybrids with a whole set of resistance genes into production will ensure a stable harvest of potatoes without the use of chemical means of protection against late blight.”
In foreign laboratories, work on the creation of late blight-resistant potatoes is already being carried out by the method of transgenesis. Genetically modified varieties have been created - Desiree, Victoria, Maris Piper. Their resistance to late blight is provided by two or three genes transmitted from wild potato species.
Russian scientists have created new domestic hybrids by the method of classical selection. Their uniqueness lies in the variety of combinations of resistance genes that provide protection against disease. The resistance gene pyramid is effective as long as at least one of its components recognizes the corresponding virulence gene and triggers a defense response. The sources of genetic material for the long-term resistance hybrids described in the article were 2 cultivated potato species and 20 wild ones, including South American species rarely used by breeders.
In the future, scientists have to find out which of the studied and described hybrids better and more fully convey valuable traits to new generations when crossing.
This work was supported by a grant from the Russian Foundation for Basic Research in cooperation with the Royal Society of London, No. 20-516-10001 Ko_a “Study of potato resistance genes to late blight and their role in the formation of a diversity of effectors in a pathogen”.