Effects of vernalization time on budding,bolting and flowering of pakchoi

Three inbred lines of pakchoi with different bolting traits were used as test materials,and their budding,bolting,flowering and plant growth were observed after vernalized in 10℃/10 h light period and 4℃/14 h night period for 0,20,25,30,35,40 and 45 d respectively.The results showed that the longer the vernalization time was,the shorter the duration from the vernalization end to budding,bolting or flowering,and the differences among different treatments were large.When the vernalization time was 20 d,90%of the line 09-1-328c with early bolting could bolt and flower though the needed time was longer,and a 30 d vernalization was appropriate.When the line 08-1P-76 with moderate resistance to bolting was vernalized for 30 d,81.8%of the plants could bolt,and when the vernalization time was 35 d,all the plants could bolt and flower.When the line 08-1P-89 with late bolting was vernalized for 35 d,only 44.8%of the plants could bolt,and 40 d vernalization could make all the plants bolt.