Abstract:

Threeyears phenological variation after afforestation and annual growth of 7 larch (Larix) species, 7 hybrid (intraspecies or interspecies) families were observed and measured in Dagujia forestry station in Qingyuan County, Liaoning Province. Variance analysis, principal components analysis and canonical correlation analysis were respectively used for analyzing phenological variation, phonological type classification and relationship of growth and phenology. The results showed that all the phonological characters (excluding branch bud bursting phase) were significantly different among species and families, as well as among individuals within families, which suggested that there was great variation either for individual tree selection or family selection. Larix gmeliniileafed and sprouted earliest in spring, and had earliest cessation of shoot elongation in late summer among all species and hybrids, followed by L.olgensis, L.sibiricaand L.principis rupprechtii.The top bud formation of L.olgensis var. koreanaand L.deciduawas 15 days later than L.olgensis. Among all the species and hybrids, L.kaempferi had latest timing of the bud bursting and leafing as well as top bud formation. All the interspecies hybrids possessed stronger diseaseresistance than their male parent species did and better cold acclimation than their female parent species did, while their phenology behaved matroclinous inheritance. Fourteen genetic materials were divided into four phenological types according to the result of PCA. Except branch leafing and leader sprouting, all phonological characters were significantly correlated with the growth and were reliable traits for predicting their performance. L.kaempferi, as one of successful exotic species in northern China, grew fastest, followed by L.olgensisand L.olgensis var. koreana. Interspecific hybrids between L.kaempferiand L.olgensis, L.gmeliniiand L.principisrupprechtii expressed heterosis on growth. Therefore, the hybrids may be suitable materials for afforestion in the north eastern region.

Key words: larch (Larix) species, intraspecies families, interspecies hybrid families, phenology, phenological type, early selection