Table 1.

Assessment of cultivar resistance to P. brassicae Race 4 in different growth stages.

	Clubroot incidence (%)
Cultivar	Pre-cortex splitting stage	Cortex splitting stage	Post- cortex splitting stage
“JNYB”	3.0 ± 1.4 c *	10.3 ± 1.9 b *	84.7 ± 5.9 a *
“DHBC”	0 ± 0 b	0.9 ± 1.4 b	3.8 ± 1.1 a
	Clubroot index
Cultivar	Pre-cortex splitting stage	Cortex splitting stage	Post- cortex splitting stage
“JNYB”	6.5 ± 1.9 c *	18.5 ± 3.7 b *	43.9 ± 5.6 a *
“DHBC”	0 ± 0 c	2.8 ± 0.9 b	7.1 ± 1.1 a

A total of 20 randomly selected samples were treated and measured in each replication, 3 replications were conducted. Data were presented by mean value ± standard error (SE). Letters or * indicates significant differences among each development stages or between two cultivars respectively. Significant differences were analyzed by one-way ANOVA and Student’s t test on P < 0.05. The disease incidence and index of mock of both cultivars were 0.