Selection and Identification of Biocontrol Agents Against Cassava Blight Bacteria
298 bacterial isolates were recovered from eight different microenvironments of field-grown cassava plants. of that, 160 (53.69%) expressed protease, 57 (19.13%) produced cellulase, 7 (2.35%) expressed chitinase, and 203 (68.12%) secreted siderophores; 11 (3.69%) produced glucanase, 150 (50.34%) expressed IAA, and only 9 (3.02%) representative isolates were for in vitro antagonism. ARDRA and identification of antagonistic bacteria identified 21 distinct groups ( G1-21) with the similarity coefficient of 50% among the 298 isolates, BOX-PCR fingerprint analysis revealed that isolates in different ARDRA groups had dissimilar genotypes. Eleven representative isolates were evaluated for their efficacy against cassava blight bacterial mildew caused by Xanthomonas axonopodis pv. Manihotis in the greenhouse, the isolates showed biocontrol efficacy ranging from 44.14% to 100%. Eight of them (HWY-3-1 (100%), DBS-5 (85.96%), HS-4-3 (82.88%), DHWP-1 (79.37%), HWYT-3-2 (77.88%), HWS-4-3 (77.84%), DHNS-3-5 (65.34%), DHWR-5-1 (61.83%) attained the efficacy over 60%. HWYT-3-2 and HNR-3-7 significantly suppressed the disease at 30 dpt, and HWYT-3-2 provided significant disease protection from 30-40 dpt, the average bio control efficiency was 38.11%. The strategy of the study was feasible, and found one strains HWYT-3-2 Bacillus pumilus of BCAs against CBB control.
Cassava bacterial blightselection and identificationantagonism activitycluster analysebicontrol efficiency