Evaluation On Cold Resistance Of The Selections Of Hybrid Hazelnuts (C.heterophylla×C.avellana)

Hybrid hazelnuts(C.heterophylla×C.avellana)was a kind of hybrid.It was wild hazelnuts centralized distribution area in N42(?)—47(?)of china.So,it was very importance to nurture cold resistance varieties and evaluate the cold resistance's far,it was so less at the study of hybrid hazel's cold hardiness in china.Based on 18 clones of the excellent hybrid hazelnuts,and system researched it's Physiology and Biochemistry indicators,made use of correlation analysis confirming the cold hardiness of the evaluation index,establishing the assessment system and Identified the cold resistance of different clones.According to the results identified, elected three clones(84-349,84-237 and 84-572)and researched the respiratory intensity,electric conductivity,soluble sugar and soluble protein of branches in dormant period.Main conclusions as follows:1.Determined the order of cold hardiness of 18 clones with assessment system.Integrated index value of cold resistance of each advanced selection was obtained based on weight and its function value.The cold resistance order was 84-349＞81-23＞85-127＞B-3＞84-69＞84-545＞81-9＞83-33＞84-1＞84-72＞84-254＞84-48＞84-402＞84-237＞82-11＞84-226＞B-21＞84-572.2.Hybrid hazelnuts branch entered dormancy period around the end of October or early November,early December to the end of January was the deep dormant period,early February to early April was the late dormant period.The end of dormant period was the early April.Stronger cold hardiness of the clones entered dormant period earlier,weaker cold hardiness of the clones entered dormant period later.3.The respiratory intensity curves of hybrid hazelnuts branch was inverted single peak at the dormant period.The respiratory intensity was higher at the early and late of dormant period. The respiratory intensity was lower at the deep dormant period;Stronger cold hardiness of the clones had lower respiratory intensity and weaker cold hardiness of the clones had higher respiratory intensity at the early and late of dormant period.4.The electric conductivity curves of hybrid hazelnuts branch was inverted single peak at the dormant period.At the early and late of dormant period,it's had a higher electric conductivity with a higher temperature.But,at the deep dormant period,it's had a lower electric conductivity with a lower temperature;during the dormant period the electric conductivity and the cold hardiness was negative correlation,that the stronger cold hardiness of the clones had a lower electric conductivity than the weaker ones.5.The osmoregulation substance(coluble sugar and soluble protein)of hybrid hazelnuts branch was increased at the early of dormant period,and it was the highest at the deep dormant period.In the process of the deep dormant period,the content of soluble sugar was decreased, but the content of soluble protein was increased.During the dormant period the content of soluble sugar and the cold hardiness was positive correlation,that the stronger cold hardiness of the clones had a higher content of soluble sugar than the weaker ones.