Study On The Methods For Bolting Tolerance Identification Of Spring Cabbage

Cabbage(Brassica Oleracea L.)is a kind of important vegetable and play an important role for year-round vegetable consumption supply.But when it is planted in winter,the cabbage is easy to bolt in advance because of inappropriate weather or cultivation management.The bolting in advance brings heavy losses in yield and quality.Flower bud differentiation,the basis of bolting,is the initial symbol that cabbage transform from nutritional growth phase to reproductive growth.In the development process from flower bud differentiation to flowering,the cabbage's morphology and physiological metabolism will changed simultaneously.The main results were as follows:The tolerant ability for bolting in advance of four cabbages,2006042,A2-14,Chunfeng and G1-5 were distinguishing,the variety of G1-5 was the best tolerant for bolting in advance,and the 2006042 was the easiest to bolting in field.By analyzing the correlation between the morphology and bolting tolerance,the result showed that there was a significant negative correlation between the compaction of the cabbage and the bolting-rate.So the compaction can be used as a morphology index to identify the bolting tolerance of spring cabbage.The indoor identification was performed used two varieties,the 2006042 and Chunfeng.The results showed that inducing the seedling with ten leavies under 5℃for 30 days,it could distinguish the easy bolting and tolerant bolting varieties.The development process of the flower bud differentiation of cabbage was observed by paraffin section,the process was divided into six stages,vegetative phase,prepared differentiation phase, flower bud initiation,sepal differentiation phase,stamen differentiation phase,pistil and anadem differentiation,after the flower bud differentiation finished,followed the period for bud appeared and bolting period.The early-bolting cabbage 2006042 passed the critical period of flower bud differentiation after 182 days,it was earlier than the late- bolting cabbage Chunfeng about 8 days in all stages.By studying the related physiological and biochemical messages during flower bud differentiation and bolting process for 2006042 and Chunfeng,the result showed the soluble protein content and sucrose content of 2006042 were higher than that of Chunfeng in each stage,so they can be used as the reference physiological indexes to identify the bolting tolerance of the spring cabbage.By analyzing the protein components during the flower bud differentiation and bolting process in 2006042 by SDS-PAGE,the result showed there were three specific protein bands(48.4kDa,18.8 kDa,14.5kDa) appeared,accompanied with the specific protein band(84.0 kDa) disappeared and specific protein band(17.4 kDa) weakened,it suggested these proteins be likely to participate the bolting regulation.