杉木種子來自中國13省區之42個種源。樹高與胸徑生長資料分別於11，16及18年生時測定而得。生長木軸取自胸高部位，並應用排水法以測析木材密度。另以電泳技術測得PGI、SKD及6PGD等同功酶之頻率。木材密度最大值為0.310，來自江蘇省，而最小值為0.273，來自中國西南的貴州省。這兩個省區之密度值分別與其相鄰省區者比較，均有差異。木材密度值與SKDH及6PGD二同功酶頻率並無顯著之相關性存在，但與PGI同功酶卻顯出微弱之相關關係。由於無法測得直線型地理或氣候趨向之變異，我們認為杉木之木材密度係因地域局部因素而致呈現逢機型變異。
Seeds of China-fir were obtained from 42 provenances in 13 provinces of China. Height and diameter were measured at the ages of 11, 16, and 18 years. Wood density samples were taken by increment core at breast height and were assessed by the water displacement method. Isozyme frequencies of PGI, SKDH, and 6PGD were observed from electrophoresis. Wood density ranged from a high of 0.310 in Jiangsu Province to a low of 0.273 in Guizhou Province in southwestern China. The China-fir in these 2 provinces differed from those of their neighboring Provinces. Correlation between density and isozyme frequency was not significant for SKDH and 6PGD; it was weak for PGI. Since there were no linear geographic or climatic trends detected, random variation due to local factors appears to be a suitable description for wood density in China-fir.
