温度对枇杷花粉管生长和胚囊寿命的影响

Effects of temperature on pollen tube growth and ovule longevity in loquat(Eriobotrya japonica)

【目的】阐明温度对枇杷花粉原位萌发、花粉管生长和胚囊寿命的影响,明确枇杷花粉萌发、花粉管生长的最适温度,为枇杷花期管理及生态区划提供新的科学依据。【方法】以‘大五星’为试材,将其离体花枝置于不同温度的恒温箱中进行培养,用‘龙泉5号’进行异花授粉,授粉后不同时间段分别采集花朵,采用荧光显微观察方法观察统计花粉萌发和花粉管生长和胚囊活力情况。【结果】在10.0、15.0和20.0℃的温度条件下花粉萌发率、被花粉管生长穿过的花柱比率和有花粉管的胚珠比率显著高于其他温度,当温度为5.0℃时花粉的萌发率仅为10%,温度升高至25.0、30.0℃时,萌发率又分别显著下降至65%和45%。当温度为5.0、30.0℃时,在授粉后120 h均未发现有花粉管穿过花柱生长至胚珠。【结论】温度对枇杷花粉萌发、花粉管生长和胚囊寿命有显著影响,枇杷花粉萌发的最适温度为19.9℃,花粉管最适宜的生长温度为18.0℃。

【Objective】To elucidate the effects of temperature on pollen tube growth and ovule longevity inloquat,to determine the cardinal temperatures（Tmin,Topt and Tmax） for loquat,and to provide biologi-cal data for flowering management and ecological regionalization of loquat.【Methods】‘Dawuxing＇wasused as materials,and the branches of‘Dawuxing＇loquat with flowers were removed from plant andplaced in the artificial climate chamber with their bases immersed in 1%（w/v） sucrose at different temper-ature. The flowers were pollinated by hand with pollen of the cultivar‘Longquan No.5＇,then the flowerspollinated were sampled at different hours after pollination and the pollen germination,pollen tubegrowth and ovule longevity were observed by fluorescence microscope.【Results】Results showed that therate of pollen germination,the rate of style and ovule traversed by pollen tubes in the flowers cultivated at10.0,15.0 and 20.0 ℃ were significantly higher than those of flowers cultivated at 5.0,25.0 and 30.0 ℃.The rate of pollen germination was only 10% at 5.0 ℃,while the rates of pollen germination declined to65% and 45% at the temperatures 25.0 and 30.0 ℃ respectively. And there were no styles or ovules traversed by pollen tubes in the flowers cultivated 120 HAP at 5.0 and 30.0 ℃.【Conclusion】The resultssuggested that temperature hads significant impact on pollen germination,pollen tube growth and ovulelongevity,and the results of regression analysis showed that the Topt of pollen germination and pollentube growth were 19.9 ℃ and 18.0 ℃ respectively in loquat.