Breeding report of an new improved cultivar of Ping’ou hybrid hazelnuts‘Liaozhen 1’

Abstract: Corylus heterophylla Fisch. is one of the 8 wild hazelnut species native to China, has high cold resistance and strong adaptability, and some defections such as small nut size, thick shell and low yield. C. avellana L. is the most cultivated species in the world with the advantages of big nut size, thin shell and high yield. But this species is not suitable for the climate conditions of many places in China. Since 1980s, the cross-breeding has been explored in China by using superior selections of C. heterophyl- la Fisch. as female parent and the mixed pollen from the advanced seedlings of C. avellana L. as male parent. The series of candidates of hybrid hazelnuts, named Ping’ou in Chinese, were selected, which had the characteristics of big nut size, high kernel percentage, high yield, and strong adaptability. The promotion and application of the new cultivars of Ping’ou hybrid hazelnut were carried out since 2000. Now there are about 15 main cultivars of Ping’ou hybrid hazelnut released in China.‘Liaozhen 1’was hybrid in 1984, first selected in 1988 and named in 2001 with the breeding number of 84-349. The trees of‘Liaozhen 1’are of vigor and productive. The nuts can be harvest at the beginning of August in Anq- iu, Shandong province and at the beginning of September in Dalian, Liaoning province. Nuts of‘Liao- zhen 1’are oval in shape, gray in color, large in size (2.5 g), with the thin shells (1.3 mm) and 43% kernel percentage in weight. Kernels have glabrous pellicles with 70% blanched after baking. The nut con- tents of fat and soluble protein are 58.14% and 5.33%, respectively. The trees of‘Liaozhen 1’show moderate resistance to cold and strong resistance to dry-hot environment.‘Liaozhen 1’can be cultivat- ed in the area in China where the annual average temperature is higher than 10 °C, but is not suitable for the arid region and the semi-arid region.‘Liaozhen 1’is one of the best cultivars of Ping’ou hybrid ha- zelnuts that can be used for the in-shell market at present. The plants of Corylus have the trait of self-in- compatibility, so two or more cultivars as the pollinizer are recommended in commercial orchards. The suitable pollinizers for‘Liaozhen 1’are‘Ping’ou 15’‘, Ping’ou 33’and‘Ping’ou 545’, etc.