Variation in Seed and Seedling Traits among Fifteen Chinese Provenances of Magnolia officinalis

Abstract

Magnolia officinalis seeds were collected from 15 different provenances, ranging from 336 to 1387 m in China. The main objective of this study was to identify germplasm resources of M. officinalis by test seed traits, seed germination, seedling traits, and seedling growth rate. There are significant differences among provenances in all studied attributes except relative growth rate and the net assimilation rate. Seed weight exhibited maximum variation among provenances in seed morphometric traits with a significant positive correlation in terms of average annual temperature and average annual rainfall, and negative correlation with latitude of seed origin. Overall average seed germination in nursery was 59.4% varying from 26.6% to 91.2%. Seedling height decreased by geographical latitude gradually from south to north, while stem diameter declines from east to west. That means the geographic variation of the plant at the seedling stage manifests a two-way variation with the latitude and longitude. Seed of Longsheng, Yangxian, Jingning, Wuyishan, Kaixian and Ningqiang provenance have been identified suitable to produce quality seedlings. It can be concluded that the observed patterns of variation will have implications for genetic resources conservation and tree improvement.