INTERSPECIFIC HYBRIDIZATION OF HAZELNUT AND PERFORMANCE OF 5 VARIETIES IN CHINA

The hazelnut (Corylus heterophylla Fisch.) has been well known since ancient times and is widely distributed in northern China. Until now this kind of hazelnut has only grown in the wild. Compared with the European hazelnut (Corylus avellana L.) the nut weight of Corylus heterophylla Fisch. is smaller (about 1.0 g less), and the yield is poor (about 300 kg/ha), but it has very good winter hardiness. A breeding program of interspecific hybridization between Corylus heterophylla Fisch. and Corylus avellana L. was initiated in 1979 at the Economic Forestry Research Institute of Liaoning Province (EFRI). The aim of this program included good climatic adaptability, high and constant productivity, bigger nut size, good kernel quality, high winter hardiness. During the period 1980-1986 more than 2,300 hybrid seedlings were obtained, while nearly 40 fine selections were selected during the period 1988-1996. From 1991 to 1999 hazelnut variety and advanced selection trials were carried out in different climatic zones in Liaoning province and other province, with the same aims as the aforementioned program. 5 new varieties were released in 1999, these being: ‘Pingdinghuang’ (80-43), height of 8-year old tree = 1.89 m, diameter = 1.78 m, nut weight = 2.4 g, percent kernel = 41%, yield per tree = 1,597 g; ‘Bokehong’ (82-4), measurements for the same parameters were 2.66 m, 2.28 m, 2.1 g, 46%, and 1,749 g respectively; ‘Dawei’ (84-254), measurements for the same parameters were 2.30 m, 1.58 m, 2.5 g, 41%, and 1,283 g respectively; ‘Jinling’ (84-263), measurements for the same parameters were 2.13 m, 1.67 m, 2.2 g, 40% and 1,098 g; ‘Yuzhui’ (84-310), 2.51 m, 1.66 m, 2.0 g, 43%, and 1,005 g respectively. The new varieties showed a good growth rate and a high yield in the temperate zone (between 32 and 42°N, average annual temperature 7.5-14°C) in China. In 2001 and 2003 the back-crosses were carried out in both Italy (Università di Torino) and China. Now a new selection trial is being carried out in Dalian, where 10 selections (such as 84-69 and 84-525) are being evaluated.