温度和光周期对楸树抗寒性生理生化指标的影响

Effects of temperature and photoperiod on cold resistance of physiological and biochemical parameters of Catalpa spp.

为探究低温和短日照与楸树抗寒性诱导的关系,以2年生滇楸和灰楸嫁接苗为试材,进行4个温度与光周期组合处理:常温长日照(16 h/8 h,23℃)、常温短日照(8 h/16 h,23℃)、低温长日照(16 h/8 h,5℃)、低温短日照(8 h/16 h,5℃),研究温度和光周期对楸树抗寒性发育的影响,利用电导法(Electrolyte leakage,EL)和电阻抗图谱法(Electrical impedance spectroscopy,EIS)测定抗寒性的变化,测定质膜三磷酸腺苷酶(ATP酶)和5′-核苷酸酶(5′-AMP酶)、可溶性糖及淀粉含量等生理生化指标。结果表明,低温长日照(16 h/8 h,5℃)、低温短日照(8 h/16 h,5℃)对楸树抗寒性增强诱导最快,其中低温短日照处理对抗寒性的诱导又强于低温长日照处理,表明温度对楸树抗寒性增强起主导作用,光周期起次要作用,且温度和光周期对楸树抗寒性的诱导为非加性关系;常温长日照(16 h/8 h,23℃)处理下,2种楸树抗寒性均得到增强,表明在23℃仍能诱导楸树抗寒性的增强;高频电阻率r测定的抗寒性与电导法测定的抗寒性均显著相关,其中低温短日照处理下的抗寒性与电导法测定的抗寒性极显著相关,相关系数达到0.77,表明高频电阻率r可用于楸树抗寒性的测定;随着2种楸树抗寒性的增强,ATP酶和5′-AMP酶活性也上升,均在处理第30天时显著上升并达到高值,其中5′-AMP酶活性均高于ATP酶活性,且滇楸的2种酶活性均高于灰楸。

In order to study the relationship between low temperature and short photoperiod on the induction of cold resistance of Catalpa spp.,two-year-old Catalpa fargesii f.duclorxii and Catalpa fargesii Bur.grafted plants were used as test materials,and four combinations of temperature and photoperiod treatments were carried out:a normal temperature(23℃)with a long photoperiod(16 h light:8 h dark cycle),a normal temperature(23℃)with a short photoperiod(8 h light:16 h dark cycle),a low temperature(5℃)with a long photoperiod(16 h light:8 h dark cycle),a low temperature(5℃)with a short photoperiod(8 h light:16 h dark cycle).The effects of temperature and photoperiod on the development of cold resistance of C.spp.were studied,and the cold hardiness was measured by the electrolyte leakage(EL)methods and the electrical impedance spectroscopy(EIS).The physiological and biochemical indexes of ATPase,5′-AMPase activity,soluble sugar and starch content were measured.The results showed that low temperature and photoperiod treatments(16 h light:8 h dark cycle,5℃and 16 h light:8 h dark cycle,5℃)increased cold hardiness of C.spp.quickly,the cold hardiness in low temperature and short photoperiod treatment was stronger than that in low temperature and long photoperiod,indicating that temperature played the dominant role on cold hardiness of C.spp.,whereas photoperiod played a secondary role.The effects of temperature and photoperiod on cold hardiness of C.spp.were not additive.The cold hardiness of C.spp.could increase in normal temperature and long photoperiod treatment(16 h light:8 h dark cycle,23℃),indicating that 23℃could increase cold hardiness of C.spp.too.The cold hardiness of C.spp.measured by the specific high-frequency resistance r and EL correlated significantly.The cold hardiness of C.spp.measured by the specific high-frequency resistance and EL in low temperature and short photoperiod treatment(8 h light:16 h dark cycle,5℃)correlated significantly too,with the linear correlation coefficient 0.77,indicating that high-frequency resistivity r could be used to determine the cold hardiness of C.spp..The ATPase and 5′-AMPase activity increased gradually with increased cold hardiness.On the 30th day,the two enzyme activities increased significantly and reached a high value,the 5′-AMPase activity was higher than ATPase activity,and the two enzyme activities of C.fargesii f.duclorxii were higher than that of C.fargesii Bur..