PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Sheath blight of rice caused by Rhizoctonia solani, is the most serious disease severely damaging the rice production in Asia including Pakistan. Durable solution is a dire need to manage this disease for which the study was planned to identify the resistance sources in advanced local and exotic rice germplasm. Development of resistant varieties is the most reliable, economical and efficient strategy to manage this disease. The objective of the present study was to identify the genotypes harboring resistance against sheath blight disease in rice.  To cope this issue,  rice germplasm (85  advance rice lines/mutants/varieties) originated  from  IRRI  and  Pakistan  were  inoculated  with  Rhizoctonia solani  through toothpick inoculation method under field conditions during 2020 and 2021.  The results revealed that none of the genotype reflected immune response against sheath blight disease while two rice varieties, Noor Basmati and IRRI-29 with disease severity (15.21-15.77% and 18.39-19.97% respectively) were found resistant in both years. Eight varieties/lines Basmati 515, Chenab basmati, Punjab basmati, NM-7, NM-11, NM-15, NM-16 and NM-17 categories as moderately resistant  with the disease severity ranging from 21 to 30% in both years. 26 varieties/lines were found moderately susceptible with the disease infection of 31.33 to 44.94% while 49 were susceptible with 45.72 to 65.26% in 2020-2021. The resistant and moderately resistant genotypes could be used in breeding program to develop sheath blight disease resistant cultivars in Punjab, Pakistan.