Responses Of Different Provenances From Camptotheca Acuminate To Cold Stress

In this paper, studies on cold resistance were conducted on pot leaves of ten 1-year- Camptotheca acuminata species under stimulated freezing treatment, examined the physiological and biochemical and Camptothecin of Camptotheca acuminata seedlings on changes. The purpose is to early cold resistance of Camptotheca acuminata different provenances lay the foundation for breeding, but also for its promotion and application of production practices to provide a scientific basis. The main results are as follows:1. Under cold stress all sources of leaf relative water content significantly decreased, bound water content increased, bound water and free water ratio increased, and cold resistance were significantly correlated. Chlorophyll content increased and then decreased, indicating that low temperatures cause dysfunction to decreased chloroplast, chlorophyll a / b ratio increased shows that the destruction of low temperature on chlorophyll b than chlorophyll a serious,The carotenoids content was increased and then decreased, but the movements not by much.2. Leaves under cold stress sources membrane permeability and MDA content increased, the source resistance to a strong increase in small species. The activities of SOD, PODand CAT were tested more consistent changes in first and then decreased or stable trend, indicating that activity affected in the early fall, late protective enzyme activities increased. Soluble protein content increased, and between cold resistant showed significant positive correlations, soluble sugar content was increased and then decreased, significantly higher than the control. The rise of free proline and cold resistance of the existence had certain relevance, stronger cold accumulation of more than provenance.3. Under cold stress, the CPT of Kunming and Guiyang were significantly higher than Longquan, among the different low temperature treatments to the highest content of -9℃for 0.1035%.4. In terms of cold resistance, these varieties of Camptotheca acuminata could be divided into 4 groups by cluster analysis: Nanjing had the strong cold resistance; Changing, Huangshan and Nanchang had medium cold resistance; Liuyang, Longquan and Shaoyang had poor cold resistance; Guiyang, Kunming and Guilin were the poorest. This study set a basis for the introduction of camptotheca acuminata, expansion of cultivation and cultivation techniques development.