Evaluation On Cold Resistance Of Germplasm Resources And Its Physiological Mechanisms Of Actindia Arguta

In this experiment,46 germplasms of Actinidia arguta were used as test materials to explore the optimal conditions for identifying cold-resistance in TTC staining image visualization evaluation method.Each germplasm was divided into different regions according to their cold-resistance,and there are difference in cold-resistance among germplasms.On this basis,two germplasms with different cold-resistant were selected and used to monitor the changes of cold-resistance and physiological indexes during overwintering,so as to clarify the related physiological mechanisms on the cold-resistance of Actinidia arguta,which provided a theoretical basis for the identification of cold-resistant germplasms and breeding of Actinidia arguta.The main results are as follows:1.The optimal TTC staining concentration and staining times were determined that the shoot sections were stained by 0.05%TTC solution at 30?for 4 days in dark for evaluation on the cold resistance of Actinidia arguta2.The relative staining area of shoots showed an inverted"S"curve under different temperatures.The low semi-lethal temperature(LT₅₀)represented the cold tolerance of each resource of Actinidia arguta germplasm that could be calculated by logistic equation.3.The LT₅₀0 value was determined by TTC staining image visualization method with logistic equation were significantly correlated with the value by average membership method and the field germination rate,the correlation coefficients were-0.827 and-0.602 respectively,which indicated that the TTC staining image visualization method is accurate on cold-resistance and the results consistent with the actual cold-resistance in the field.4.There were differences in cold-resistance among the germplasms of Actinidia arguta.The cold-resistance of the germplasms was divided into four levels,and the cold resistant differences among intraspecific germplasms of Actinidia arguta might be related to the geographical distribution and hybridization condition.5.The cold-resistance of the shoots in Actinidia arguta increased gradually with the decreased of air temperatures during overwintering,and the ratio of bound water to free water and the contents of osmotic regulators?soluble sugar,soluble protein,free proline?increased gradually during overwintering that showed significant differences between two Actinidia arguta varieties.In generally,The strong cold-resistant variety‘Jialv'had higher values of the ratio of bound water to free water and the contents of osmotic regulators than the weak‘Xianglv'.