北方寒旱区冬油菜花芽分化过程观察

以强冬性白菜型冬油菜陇油6号、天油4号、甘蓝型冬油菜07-G01为材料,对不同抗性冬油菜在中国西北寒旱区的生长发育进行研究。研究结果表明,在西北寒旱气候条件下冬油菜花芽分化始于冬前-2℃左右至-10℃左右时,花芽分化仍在继续,此时已进入花瓣原基和雄蕊原基分化期。当气温降至-15℃时,花芽分化减缓或停止。冬后气温升至-4℃~10℃左右时,花芽分化重新开始,且随着气温的升高花芽分化速度加快。经过10 d左右即可完成一个花器的分化。花芽分化与品种抗寒性强弱有关,抗寒性强的陇油6号花芽分化早,但花芽分化速度较慢。甘蓝型冬油菜的花芽分化晚于白菜型冬油菜,一般在返青后才开始花芽分化。根据观察结果将白菜型冬油菜花芽花器分化按向心分化顺序划分为3时段7时期,即冬前花芽分化启始期、越冬休眠期与冬后花芽快速分化期3个时段,快速分化时段又可划分为7个时期。

Flower Differentiation of Winter Rapeseed in Northwest Cold Arid Regions

The flower development and differentiation of different cold resistance type winter rapeseeds were characterized using strong cold resistance cultivars Longyou 6,Tianyou 4 and 07-G01.Results showed that in Northwest cold arid regions flower differentiation of winter rapeseed began at-2 ℃ before winter and continued at-10 ℃ when flower differentiation came into the petal primordia and stamen primordium stages.When temperature dropped to-15 ℃ the differentiation slowed down or even stopped.Flower differentiation restarted in spring when temperature rose to-4 ℃ to 10 ℃,and developed faster with the rising temperature.The flower differentiation completed in ten days.It is also related to the cold resistance of a cultivar,for example,Longyou 6 is an ultra strong cold resistance cultivar,the flower differentiation started early and developed slowly;the flower differentiation of B.napus is later than that of B.rapus,it usually started until wheat turning green.Based on the research the flower bud differentiation of winter rapeseeds could be divided into three stages,ie initiation stage before winter,dormancy stage during winter and rapid development stage in spring.The third stage can be divided into seven short steps.