乙烯利对大白菜制种后期化学除蕾技术的研究

大白菜花期长达1.0～1.5个月,开花需要消耗大量的养分。当大白菜制种田双亲之一进入终花期后,连续对另一亲本进行乙烯利喷施除蕾,可改变植株的源与库关系,减少无效分枝,促使营养物质向已结荚的种子正常发育积累,从而提高种子千粒重和有效产量。在大白菜花期,对植株喷施不同浓度（0、4 000、6 000、8 000、10 000和12 000 mg/kg）和次数（0、1和2次）的乙烯利溶液,研究不同乙烯利浓度和喷施次数的除蕾效果、抑制末花期无效分枝的作用、对制种产量和种子纯度的影响。结果表明：用40%乙烯利8 000～10 000 mg/kg药液连续喷施2次,间隔期为4～5 d,平均受药量10～15 mL/（株.次）,化学除蕾以及抑制末花期无效分枝发生的效果最佳,且对制种产量、种子发芽率以及纯度没有显著影响,能有效提高种子的千粒重和有效制种产量。

Study on Chemical Buds Removing Technique by Ethephon at the End of Chinese Cabbage Blooming Period in Hybrid Seeds Production

The blooming period of Chinese cabbage consums a large amount of nutrients,lasting naturally for 1.0-1.5 months.When one of the parents enters flowering phase,spraying continuously ethephon on the buds of the other parent,could change source and sink relationship of the plants,reduce invalid branches,and promote the accumulation of nutrients in seeds.In blooming period,spraying ethephon of different concentrations（0,4 000,6 000,8 000,10 000 and 12 000 mg/kg） by different spraying times（0,1 and 2 times） on Chinese cabbage,the effects on buds removing,invalid branches reducing,seeds yield and purity were studied.The results showed that spraying 40% ethephon of 8 000-10 000 mg/kg by 2 times,on a interval of 4-5 d,average dosage 10-15 mL/（plant·time）,gave the best effect of buds removing and invalid branches reducing,without harming significantly the seeds yield,purity and germination percentage,so the TKW and valid seeds yield could be significantly improved.