[Screening and Research Cyathula officinalis in Cold Hardy Physiological Characteristics].

To explore the mechanism in cold-resistant of Cyathula officinalis seedlings,in order to provide a theoretical basis for variety breeding and resistance cultivation of Cyathula officinalis.

Collected the materials in main producing areas of Cyathula officinalis,and the Cyathula officinalis growing into seedling with five pairs of leaves were used to research. The seeds were deal with low temperature stress,and the seedlings of morphological and physiological indicators of Cyathula officinalis were measured,membership function method and low temperature variation index were used to screen and evaluate the cold-tolerance of the Cyathula officinalis.

Soluble sugar,proline,soluble protein,fresh weight,plant height can be used as the evaluation indexes of cold-resistant Cyathula officinalis. The red and white Cyathula officinalis from Baoxing county in Chongxing village and the white Cyathula officinalis from Hanyuan county all had a good cold-resistance.

The cold-resistant in Cyathula officinalis are different in different areas, and cold tolerance is positively correlated with the content of osmotic adjustment substance of Cyathula officinalis seedlings.