EVALUATION OF RICE GERMPLASM AGAINST XANTHOMONAS ORYZAE CAUSING BACTERIAL LEAF BLIGHT

Bacterial blight (BB) caused by Xanthomonas oryzae pv oryzae is the most destructive disease of rice in Pakistan due to its high epidemic potential: Forty seven rice accessions comprising 6 crosses, 8 wild rice, 2 commercial varieties, 23 isogenic line,(-)7 new plant type and 1 mutant, were evaluated against 25 isolates (X01, X02, X03, X04, X05, X06, X07, X08, X09, X010 X011, X012, X013, X014; X015, X016, X017, X018, X019 X020, X0139, X0140, X0143, X0146, X067) in bulk form wider heavy inoculum load in glass house.-Data were recorded at 15 days after inoculation on 0-4 rating scale. Interspecific crosses showed a range from 1.0 to 13 cm, wild rice alone showed range from 1.0 to 12cm, isogenic lines of rice-showed range from 1.2 to.29.8 cm, while new plant type, mutant and commercial varieties varied within the range 1.0 to 12.0cm, 6.6, and 16.8 to 18.4 cm, respectively. Resistance against bacterial leaf blight isolates was observed in IR6 x Oryza nivara, O. longistminata; O. punctata, O. nivara and IRBB24 (isogenie line). Bas.385 and KS282, the cultivated rice were susceptible to all isolates. Use of resistant wild species viz., O. nivara, O. longistminata and O. punctata are therefore recommended for-transgressing-bacterial blight resistance to the cultivated rice.