[目的]探讨映山红的开花习性及花粉生活力.[方法]以映山红(Rhododendron arborescens)为试验材料.观察映山红(R.simisiiPlanch)开花的习性;采用离体培养基萌发测定法,以及培养基中蔗糖的浓度、培养温度、硼酸、钙离子等因素对花粉萌发和花粉管伸长的影响.[结果]映山红花期4～6月,单花期3～5 d;花紫色,2～6朵簇生于枝端;花萼5裂,长2～4 mm;花冠宽漏斗状,长4～5 cm,5裂;雄蕊7～10,花药紫色;柱头头状.蔗糖浓度为5%时映山红花粉萌发最好;光照条件下25℃时萌发率最高,达70%以上;培养基为20mg/L硼酸+10mg/L氯化钙+5%蔗糖+0.5 g琼脂,萌发率最高达87%;在一定浓度(0～20 mg/L)范围内,钙离子对映山红花粉的萌发率影响不大,主要影响花粉管长度;对花粉萌发率的影响比较明显,浓度间差异均达显著水平,在一定硼酸浓度(0～20 mg/L)范围内,随着硼酸浓度的增加花粉的萌发率上升.[结论]该研究可为今后利用映山红开展人工育种奠定基础.%[ Objective ] To investigate the flowering habit and pollen viability of R. arborescens Planch. [ Method ] R. arborescens Planch as test material, effects of sucrose concentrations, culture temperature, boric acid and Ca2+ on the pollen germination and tube growth were studied through in vitro culture method. [ Result ] The flower season of R. arborescens Planch lasts 4 to 6 months with single flowering phase of 3 - 5 d;purple, 2 -6 flowers cluster in the end of branches; calyx 5-lobed, 2-4 mm in length; funnel-form corolla, 4 -5 cm in length, 5-lobed; 7 -10 stamens, purple anther; capitate stigmas. 5％ sucrose was proved to be the best for the germination of pollen, and the germination rate was the highest at 25 ℃ in daylight ( more than 70％ ); the optimum combination for the germination of pollen was 20 mg/L boric acid + 10 mg/L CaCl2 +5％ sucrose +0.5％ agar, under this condition, the germination rate reached as high as 87％; Ca2+ had little effect on the germination of pollen in the range of 0 -20 mg/L, while which played important role in the growth of pollen tube; the germination rate of pollen increased with boric acid concentration rose (0 -20 mg/L) , and the differences among the groups were obvious. [ Conclusion] This study would provide reference for the biological engineering of R. arborescens Planch in further research.
展开▼
