橡胶树耐低温评价及爆皮流胶差异性比较

Comprehensive evaluation on cold resistance of Hevea brasiliensis varieties and comparison of bark latex bursting differences between varieties

【目的】探讨4个橡胶树品种耐寒能力及低温所致爆皮流胶情况的差异,以期了解品种耐寒性与爆皮流胶的关系及爆皮流胶的机制,为完善橡胶树耐寒评价提供参考,也为橡胶树抗寒栽培技术及产品研发提供理论基础。【方法】人工模拟低温下,以热研7-33-97、热研7-20-59、湛试327-13、93-114等4个橡胶树品种一年生芽接苗为试材,测定其叶片的相对电导率(REC)、丙二醛(MDA)含量、可溶性糖(SS)含量、可溶性蛋白(SP)含量、超氧化物歧化酶(SOD)活性、叶绿素a(Chl-a)含量、叶绿素b(Chl-b)含量(Chl-T)、叶绿素总量、PSII最大光化学效率(F_(v)/F_(m))等生理生化指标及统计低温胁迫所致植株爆皮流胶情况,分别利用隶属函数法和主成分分析法综合比较4个橡胶树品种耐寒性与爆皮流胶耐受性的关系。【结果】4个橡胶树品种生理生化指标变化并不完全一致,4个品种的相对电导率(REC)、SOD活性均呈先升高后下降的趋势,F/F均呈逐步下降趋势,低温4~6 d的过程中,品种间SS含量差异达显著水平(P<0.05);与对照相比,93-114的MDA含量、叶绿素a(Chl-a)含量、叶绿素总量变化幅度最大,低温第6天,仅93-114的SOD活性增加;与对照相比,热研7-20-59的可溶性蛋白(SP)含量均降低,Chl-a含量、Chl-b含量、叶绿素总量均低于其他3个品种。隶属函数法和主成分分析法得出的耐寒性顺序均为93-114>湛试327-13>热研7-33-97>热研7-20-59,叶绿素含量、F_(v)/F_(m)、SS含量、SOD活性、REC、SP含量可作为橡胶树耐寒性评价的主要参考指标。【结论】橡胶树不同品种流胶个数与植株存活率与耐寒性保持一致,而流胶量与耐寒性并不一致。

【Objective】The present study investigated the cold resistance of 4 Hevea brasiliensis varieties and compared the differences of bark latex bursting performances between varieties under low temperature to acquire the relation between cold resistance and bark latex bursting status of different H. brasiliensis varieties and comprehend the mechanism of bark latex bursting. Moreover, the study could provide scientific basis for improving the evaluation on cold resistance of H. brasiliensis varieties, which could help us invent H. brasiliensis cold resistance cultivation techniques and products.【Method】Relative electrical conductivity(REC), MDA content, soluble sugar(SS) content, soluble protein(SP) content, superoxide dismutase(SOD) activity, chlorophyll a(Chl-a) content, chlorophyll b(Chl-b) content, total chlorophyll content(Chl-T), maximal photochemical yield(F_(v)/F_(m)) in leaves of 4 H. brasiliensis variety one-year-old budding seedlings were measured and the differences of their bark latex bursting performances were compared under artificial simulation of the low temperature.【Result】The physiological indexes of 4 H. brasiliensis variety leaves had different changing amplitudes under low temperature. The relative electrical conductivity(REC) and superoxide dismutase(SOD) activity in 4 H. brasiliensis varieties increased at first and then decreased, maximum photochemical yield in 4 H. brasiliensis varieties all decreased gradually. During 4-6 days after low temperature, differences of SS content in 4 H. brasiliensis varieties reached significant levels(P<0.05). Compared to those of CK, MDA content, chlorophyll-a(Chl-a) content and total chlorophyll content(Chl-T) in 93-114 had the maximum change amplitudes than those in other 3 H. brasiliensis varieties. At 6 days after low temperature, only SOD activity in 93-114 increased compared to that of CK. SP content in Reyan 7-20-59 were all decreased compared to that of CK. Moreover, the chlorophyll-a(Chl-a) content, chlorophyll-b(Chl-b) content and total chlorophyll content in Reyan 7-20-59 were all lower than those in other 3 H. brasiliensis varieties. Later, the cold resistance capacity result with subordinate function method was exactly the same as the cold resistance capacity result with principal component analysis method, the orders of the cold resistance of H. brasiliensis varieties from strength to weakness were 93-114>Reyan 7-33-97>Zhanshi 327-13>Reyan 7-20-59. Therefore, chlorophyll content,F_(v)/F_(m), SS content, SOD activity, REC and SP content can be used as the main reference indexes for evaluating the cold resistance of H. brasiliensis in the future. 【Conclusion】The total number of bark latex bursting positions in different H. brasiliensis varieties and their survival rates were consistent with their cold resistance capacities. Nevertheless, bark latex bursting areas of H. brasiliensis varieties were not consistent with their cold resistance capacities.