7个短枝木麻黄种源耐寒评价及综合分析

Evaluation and Comprehensive Analysis of Cold Tolerance on Seven Casuarina equisetifolia Provenances

对7个短枝木麻黄种源的离体小枝在人工气候箱中进行梯度低温处理,在25℃,5℃,0℃,-5℃和-10℃温度下处理24 h,重复3次,每个种源的每个处理采集10株苗的枝条,测定了渗透率、丙二醛含量、脯氨酸含量、可溶性蛋白含量,可溶性糖含量等9个耐寒指标。通过半致死温度评价了7个种源的耐寒能力,并通过耐寒指标的特征结合相关分析对耐寒指标进行筛选。运用主成分分析、回归分析和聚类分析对耐寒指标进一步综合分析。结果表明:利用短枝木麻黄的半致死温度对7个种源进行排序,耐寒能力按种源号依次为18402>18268>18119>18267>18128>18015>18244。用逐步回归的方式建立短枝木麻黄的耐寒回归方程为Y=9.462-0.119Chl4-0.026SP1-0.039MDA1+0.051Chla3-0.008Chla2,(R2=1.000),估计精度大于98%。

The 9 physiological traits were measured with seedlings of seven Casuarina equisetifolia provenances, which treated under five low temperature gradients （25℃ , 5℃ , 0℃, -5℃ and -10℃ ） for 24 hours, the test was repeated 3 times. Ten seedlings＇ branches on per treatment per provenance were collected, and theirs nine cold resistance indexes such as permeability, MDA, proline content, soluble protein content, soluble sugar content, etc. were determined in artificial climate chamber. The cold resistance capability were evaluated by semilethal temperature（LTs0）. Combined correlation analysis and characteristics analysis, the cold-resistant indexes were screened. Principal component, regression and cluster analysis were used for further comprehensive analysis on the selected coldresistant indexes. The results show that seven C. equisetifolia provenances were sequenced in freeze resistance capability according to their semi-lethal temperature from big to small as follows： 18402 〉 18268 〉 18119 〉 18267 〉 18128 〉 18015 〉 18244; The regression equation was built by stepwise regression method： LT50=9.462-0.119Ch14-0.026SP1-0.039MDAl＋0.051Chla：0.008Chla：, （R2=1.000）, the estimation accuracy of the model was higher than 98%.