Development of an Efficient Screening Method for Resistance of Chinese Cabbage Cultivars to Black Rot Disease Caused by Xanthomonas campestris pv. campestris

Abstract

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is one of the most serious diseases of crucifers world-wide. To establish the efficient screening methods for resistant Chinese cabbage to Xcc, the resistance degree of 88 commercial cultivars of Chinese cabbage to Xcc KACC 10377 was examined. For further study, we selected six Chinese cabbage cultivars (resistant: Mansumugang, Woldongcheonha, CR Anshim; susceptible: Bulam3ho, Chunkwang, CR Nongshim) showing different disease response to the Xcc KACC 10377. According to growth stages of Chinese cabbage seedlings, inoculation density, and incubation temperature and period after inoculation in a dew chamber, development of black rot on the six cultivars was investigated. From the results, we suggest the following method for selection of Chinese cabbage seedlings that are resistant to Xcc. The efficient method is to inoculate 10-day-old Chinese cabbage seedlings with an cell suspension of Xcc at a concentration of 1.0 × 10 8 cfu/mL using the spray method and to incubate the inoculated plants in a dew chamber at 30°C for 48 hours and then transfer to a growth chamber at 25°C with 80% RH under a 12 hour light/dark cycle. Disease severity of the plant can be measured six days after inoculation.

A GBS-based genetic linkage map and quantitative trait loci (QTL) associated with resistance to Xanthomonas campestris pv. campestris race 1 identified in Brassica oleracea

“…campestris KACC 10377 ( Xcc R1) was used for the inoculation tests in this study, which was obtained from the Korean Agricultural Culture Collection (KACC; Suwon, Korea). The inoculum and inoculation protocol was conducted as described previously ( Lee et al., 2020 ) with minor modification. Shortly, using an inoculating loop, the bacterial inoculum was streaked over tryptic soy agar (TSA) plates and incubated for 48 hours at 30°C.…”