Contamination of Chinese Cabbage Soil with Plasmodiophora brassicae

Abstract

This research was performed to establish basic technology for Chinese cabbage clubroot chemical control by investigating the soil contamination of Plasmodiophora brassicae in major producing regions of fall Chinese cabbage. PCR primers were developed to detect P. brassicae, a causal agent of Chinese cabbage club-root that generally occurs in Cruciferae family. A primer set, PbbtgF761 and PbbtgR961, specifically amplified a 245 bp fragment from P. brassicae only. At places well known for fall Chinese cabbage, 10 out of 33 in Haenam-gun, 5 out of 13 in Yeongam-gun and Yeonggwang-gun, 1 out of 6 in Gochang-gun, 2 out of 12 in Hongseong-gun, and 5 out of 17 in Dangjin-si resulted positive for P. brassicae contamination. The results show that the soil contamination rate of P. brassicae was 30.3% in Haenam-gun, 38.5% in Yeongam-gun and Yeonggwang-gun, 16.7% in Gochang-gun, 16.7% in Hongseong-gun, and 29.4% in Dangjin-si. The six places where Chinese cabbage clubroot was visible by naked eye were 100% confirmed by the PCR test of the P. brassicae contaminated soil. Thus, simple PCR test may be utilized as an index to decide on chemical control of P. brassicae.

Keywords

• Beta-tubulin
• Clubroot
• PCR