Evaluation on Cold Resistance of Different Clonal Seedlings of Pinus armandi Franch.under Low Temperature Stress
[Objective]The aim of this study is to select cold-resistant varieties of Pinus armandi Franch.and enhance cultivation efficiency to advance its breeding process.[Method]Using leaves from 10 supe-rior clones of P.armandi at the seedling stage,subjected to controlled artificial low-temperature treat-ment,at the Zixi Mountain National Base of P.armandi in Chuxiong City,Yunnan Province.The low temperatures were set at 4℃,0℃,-4℃,with a reference temperature of 25℃under normal condi-tions.The dynamic variations in physiological and biochemical parameters,including chlorophyll con-tent,antioxidant enzyme activity,osmotic regulation substance,and malondialdehyde content,were measured in these leaves after 72 hours of low temperature stress.We employed principal component analysis and membership function analysis methods to assess the cold resistance of these clones.[Re-sult]The variation in each index of the clones seedlings of P.armandi under different temperature treat-ments varied among different species.Decreased temperature significantly influenced the dynamic changes of physiological and biochemical parameters in the leaves of different clonal seedlings of P.ar-mandi.As temperature decreases,a declining trend was observed in the chlorophyll content.The activi-ties of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)exhibited an initial increase followed by a decrease as temperature decreased.However,the magnitude of changes in these parameters varied among different clones.Conversely,the contents of soluble protein,soluble sugar,free proline,and malondialdehyde(MDA)gradually increased with decreasing temoerature.The principal component analysis showed that the cold tolerance of different clonal seedlings of P.armandi was primarily influ-enced by the protective enzyme system and osmoregulatory substances.[Conclusion]The comprehen-sive analysis of 10 clones using the membership function method indicates the following ranking of their cold resistance strength:NO.7>NO.3>NO.1>NO.2>NO.8>NO.10>NO.5>NO.9>NO.6>NO.4.
Pinus armandi Franch.different cloneslow temperature stresscold resistance
NETL
NSTL
万方数据
维普
