Identification of the Pi-ta2 resistance gene in rice collection specimens and far eastern rice varieties by molecular marking
Keywords:
: Oryza sativa, rice blast disease, Pi-ta2, molecular markerAbstract
Rice blast disease caused by Pyricularia oryzae Cav. (Magnaporthe grisea (Hebert Barr.)) is a serious limiting factor in obtaining the consistently high yields of rice in Primorsky Krai. The use of resistant varieties is considered as one of the most effective ways to protect plants from the disease. The most important genes in the selection for resistance to P. oryzae in Primorsky Krai are Pi-9, Pi-ta2, Pi-12(t), and Pi-zt. In this study we aimed to identify the rice resistance gene Pi-ta2 using molecular genetic marker in Far Eastern rice varieties and collection samples of Chinese and Korean origin. As a result, the Pi-ta2 gene was found in the Rassvet, Dolinniy and Lugovoy varieties. The Dubrava variety turned out to be polymorphic for the presence of this gene, since it was derived by the selection method from the Chinese variety mixture. Seven out of 30 Chinese collection samples and 14 out of the 21 Korean selection samples carried the Pi-ta2 gene. This gene was not found in the Far Eastern rice varieties. The combination of the Pi-9+Pi-ta2 genes provides absolute resistance of rice to P. oryzae. Thus, the next step in the selection for resistance to pathogens is searching for the rice variety samples with the Pi-9 gene, followed by the introgression of this gene into the varieties carrying the Pi-ta2 gene.