Molecular and field level screening for blast resistance gene donors among traditional rice varieties of Kerala

摘要

Rice blast, caused by Magnaporthe oryzae , is becoming one of the most devastating diseases of rice ( Oryza sativa L.) in Kerala. Use of resistant rice varieties had been proved to be the most effective and sustainableway to control this disease. In the present study, the existence of blast resistance genes Pi 1 , Pi 2 and Pi kh in selected landraces of Kerala were identified using the SSR markers RM224, RM527 and RM206 respectively, and further confirmed through a field level screening. Results showed the presence of gene Pi1 in nine varieties, Pi 2 in twenty varieties and Pi kh in six varieties. Infection index analysis after field levelscreening showed that nine varieties had low infection index. Landraces carrying the genes Pi 1 and Pi kh imparted moderate resistance under Kerala conditions which implied that pyramiding of these genes could improve the disease resistance in rice varieties of Kerala. Among the selected varieties, Parambuvattan and Kavunginpoothala , having both Pi 1 and Pi kh genes could be used as gene donors in further breeding programmes.