Genetic Diversity and Stability of Azadirachta indica Seed Quality Characters A Study on the Genetic Variation in the Mechanical Properties of Single Tracheids of Japanese Larix Genetic Analysis of Shrinkage of New Triploid Clones of Populus tomentosa GENETIC ANALYSES OF THE QUANTITATIVE CHARACTERS IN GINKGO BILOBA L. LEAVES Variations of Growth and Leaf Traits of Intraspecific Hybridization Clones of Populus tomentosa