Performance of cauliflower genotypes for yield and resistance against black rot (Xanthomonas campestris pv. campestris)

摘要

Black rot disease of cole crops caused by Xanthomonas campestris pv. campestris occurs worldwide and causes substantial yield loss (10-50%) including curd quality and seed vigour. Resistant varieties are very much lacking in cauliflower due to non availability of resistant donors. Twenty one breeding lines/ varieties of cauliflower belonging to early and mid maturity groups were evaluated for marketable curd yield, curd quality and also screened artificially against 4 virulent strains of X. campestris pv. campestris (Xcc-C1, Xcc-C3, Xcc-C26 and Xcc-C28) for the disease resistance. The curd maturity ranged from 50-72 days after transplanting and marketable curd weight from 253-750 g. Among the early genotypes, PN-1 produced good quality white and compact curd (238.33 q/ha) and among mid maturity group DCH 822 produced 375.00 q/ha followed by DC-76 (311.67 q/ha). Significant disease incidence (59-100%) and severity (3.95-5.34) against 4 pathogen strains were recorded, however, PN-1 and VLCE-4 showedthe minimum disease intensity (<60%) among the lines tested. Most of the lines showed partial resistance or moderate resistance, while IVMC-11 and PES showed susceptible reaction to black rot. The lines PN-1, VLCE-10, DC-76, DCH-822 showed high yield potential with better curd quality coupled with moderate resistance to black rot.