磷铝胁迫对马尾松苗期生长的影响及评价

为明晰磷铝胁迫下马尾松(Pinus massoniana Lamb.)苗期的生长变异规律，筛选出耐低磷酸铝型优良家系，本文以马尾松二代种子园54个优良家系幼苗为研究对象，对磷铝胁迫下其株高、地径、主根长和干重等生长指标进行测定并计算其耐低磷酸铝胁迫系数，将各指标的耐胁迫系数作为耐胁迫评价指标，运用相关性分析和因子分析将7个耐胁迫指标降维归纳为3个综合指标，并使用隶属函数法加权计算出综合评价值——D值，综合评价不同家系马尾松幼苗的耐低磷酸铝特性，并利用系统聚类分析进行分等定级。结果表明：低磷酸铝胁迫下，不同家系马尾松幼苗的生长均受到抑制，株高、主根长和地下部干重积累受抑制最严重；除株高与根冠比、地上部干重与根冠比呈负相关外，其他各指标之间呈正相关。家系间D值为0.155-0.919,17号家系耐低磷酸铝特性最好，25号家系最差。综上，低磷酸铝胁迫下，马尾松的长势特征为体矮径细，其干物质的积累受抑制、分配方式发生改变，使得其根冠比大幅度减少。

Effect and Evaluation of Phosphorus and Aluminum Stress on the Growth of Pinus massoniana Lamb.Families Seedling

In order to clarify the growth variation of Pinus massoniana Lamb.seedlings under phosphorus and aluminum stress and screen out the excellent families with low aluminum phosphate tolerance,54 excellent families in the second generation seed orchard of P.massoniana Lamb.were selected as the research objects.The growth indexes such as plant height,ground diameter,main root length and dry weight were measured under phosphorus and aluminum stress,and the coefficient of low aluminum phosphate tolerance was calculated.The stress tolerance coefficient of each index was used as the evaluation index of stress tolerance.The seven stress tolerance indexes were reduced to three comprehensive indexes by correlation analysis and factor analysis,and the comprehensive evaluation value-D value was calculated by membership function method.The characteristics of low aluminum phosphate tolerance of P.massoniana Lamb.seedlings from different families were comprehensively evaluated,and the hierarchical clustering analysis was used for grading.The results showed that the growth of P.massoniana Lamb.seedlings in different families was inhibited under low aluminum phosphate stress,and the plant height,main root length and underground dry weight accumulation were most severely inhibited.Except that plant height was negatively correlated with root-shoot ratio and shoot dry weight was negatively correlated with root-shoot ratio,other indexes were positively correlated.The D-value between the families was 0.155-0.919,and the No.17 family had the best resistance to low aluminum phosphate,and the No.25 family was the worst.In summary,under the stress of low aluminum phosphate,the growth characteristics of P.massoniana Lamb.are short and thin,the accumulation of dry matter is inhibited,and the distribution mode is changed,so that the root-shoot ratio is greatly reduced.