4个橡胶树品种抗寒性及恢复生长期表型特征分析

Analysis of Cold Resistance and Resume Growth Phenotypic Characteristics of Four Hevea brasiliensis Cultivars

以云研80-1983、热研8-79、云研77-4及云研73-477等4个橡胶树主栽品种的一年生幼苗为试材,测定不同低温处理后的叶片相对电导率,并应用Logistic方程计算出半致死温度(LT50),同时进行恢复生长观察,比较分析4个品种的抗寒性及低温胁迫后苗木恢复期表型特征。结果表明:4个橡胶树品种的LT50在-3.921~4.510℃,抗寒性大小表现为云研77-4>云研80-1983>云研73-477>热研8-79;恢复生长过程中,由底蓬至顶蓬,4个品种橡胶树的叶片和大叶柄抗寒性越来越强,而茎干则表现相反;4个品种对低温的敏感程度不同,表现为叶片脱落、恢复生长或抽芽时间存在较大差异。恢复生长与相对电导率测定结果基本相符,利用相对电导率的测定能在同一低温水平上快速区分不同品种抗寒性强弱,而结合恢复生长观测更能准确得出植株对低温的耐受程度。

One year old seedlings of four main varieties of Heveabrasiliensisincluded Yunyan 80-1983,Reyan 8-79,Yunyan 77-4 and Yunyan 73-477 were used as test materials.The relative electrical conductivity were determined in leaves and their semi-lethal temperatures(LT50)were calculated after the plants had been treated under a series of low temperature.The cold resistance and changes of phenotypic characteristics during resume growth of 4 varieties were compared and ana-lyzed.The results showed that,the LT50 of the four varieties was between-3.921 and 4.510℃.The cold resistance ability was evaluated as Yunyan 77-4>Yunyan 80-1983>Yunyan 73-477>Reyan 8-79.In the process of resume growth,the cold resistance of leaves and petioles from base to top of the plant became stronger and stronger,but the stem showed the oppo-site.The sensitivity of the four varieties to low temperature was different,which showed that there were great differences in the time of leaf shedding,resume growth or germination.The results of resume growth were basically consistent with rel-ative electrical conductivity.Using the relative electrical conductivity measurement can quickly distinguish the cold resis-tance of different varieties at the same low temperature level.Combined with the observation of recovery growth,it can ac-curately obtain the tolerance degree of plants to a certain low temperature.