Collection of Torreya grandis germplasm and analysis of seeds' physico-chemical characteristics

In order to reveal intra-species variations in Torreya grandis,an important oil species with dry fruit and to lay a foundation for further breeding,physico-chemical traits of 110 single tree-based germplasm resources collected based on interview with local farmer households to have an understanding of variations in germplasm,which included the length,diameter and weight of seeds with and without peel as well as protein and fat contents that affect the post-processing taste,and a correlation among the physical traits of seeds were analyzed.It was revealed that not only physical traits but also chemical ingredients varied greatly,with 3 individuals had a fat content and 9 ones had a protein content higher than or close to those of Torreya grandis 'Merrillii'.The shape index between the seeds with and without peel was most significantly correlated,so was the correlation between the weight of seeds with or without peel and length as well as diameter of the seeds with or without peel.The size of seeds without peel varied with seed shape,viz.a long and pointed-shaped seed is generally small in weight.This study has made us have a better understanding of the natural Torreya grandis population and found that some germplasm resources have potential for further cultivation and extension,which would break the phenomenon that only Torreya grandis'Merrillii' is under cultivation for more than one thousand years.In addition,it is revealed that for such tree species as Torreya grandis that has been in cultivation for more than 1 000 years,field investigation and interview with farmer households are a feasible means for selection and breeding.