Expression of 19 BnCKX genes in different tissues and at different developmental stages. No BnCKX1-6, 2-2, 2-3 and 3-4 expression was detected using quantitative reverse-transcription polymerase chain reaction qRT-PCR. The expression patterns of the 23 BnCKX genes in B. napus cultivar Zhong Shuang 11 (‘ZS11’) were analyzed by qRT-PCR. F: flowers; Le: leaves; R: roots; B: buds; 30St: stems on day 30; 7S, 14S, 21S, 30S, 40S: seeds collected at 7, 14, 21, 30 and 40 days after flowering, respectively. 7P, 14P, 21P, 30P, 40P: silique pericarps collected at 7, 14, 21, 30, and 40 days after flowering, respectively.