橡胶树优树无性系自然越冬过程生理指标变化研究

以橡胶树5个人工杂交子代优树无性系苗木为材料，通过自然越冬低温处理，以抗寒品种GT1为对照，测定了5个时间梯度下10个生理指标的变化过程，并利用隶属函数法对各无性系抗寒性进行综合评价。结果表明，整个自然越冬过程中各无性系间相对含水量、相对电导率、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性、超氧阴离子（OFR）、氨基酸（AA）、脯氨酸（Pro）、可溶性糖及可溶性蛋白含量等生理指标差异均达到了极显著（P<0.01）水平；温度较高时各无性系间丙二醛（MDA）含量差异未达到显著水平。自然越冬过程中，各生理指标呈现不同的变化规律，其中相对含水量和脯氨酸含量呈先降后升变化，SOD、POD酶活性及可溶性蛋白含量呈“升—降—升”变化，相对电导率、MDA和可溶性糖含量呈“降—升—降”变化、OFR含量呈先升后降、AA含量呈“降—升—降—升”变化。各无性系间抗寒性差异较明显，应用隶属函数法综合评价抗寒性由强到弱依次为629号＞626号＞182号＞223号＞GT1（对照）＞628号。

Changes of Physiological Indexes of Hevea brasiliensis Plus Tree Clones during Natural Overwintering

Taking the seedlings 5 artificial hybrid offspring plus tree clones of Hevea brasiliensis as materials,through low-temperature treatment of natural overwintering and taking cold-resistant variety GT1 as the control,the change processes of 10 physiological indexes under 5 time gradients were measured,and the cold-resistance abilities of the clones were evaluated comprehensively by membership function method.The results showed that during the whole period of natural overwintering,there existed extremely significant differences(P<0.01)in physiological indexes among 6 clones,including relative water content,relative electric conductivity,superoxide dismutase(SOD)and peroxidase(POD)activity,oxygen free radical(OFR),amino acid(AA),proline(Pro),soluble sugar and soluble protein contents.Malondialdehyde(MDA)content among the clones did not reach a significant level at higher temperature.The physiological indicators presented the differentchange rules in the natural overwintering process.The relative water content and proline content ascended before descended,SOD and POD activity and soluble protein content all showed an“ascending-descending-ascending”change,relative conductivity,MDA and soluble sugar content showed a“descending-ascending-descending”change,OFR content first increased and then decreased,AA content showed“descending-ascending-descending-descending”change.The cold resistance of the clones was obviously different,and comprehensive evaluation result of cold resistance by membership function method was from strong to weak 629>626>182>223>GT1(controle)>628.