內婚效果에 의한 海松集團의 分化

Effects of Inbreeding in Black Pine (Pinus thunbergii Parl)

우리나라 海岸線에 따라 分布하는 또 南海島嶼를 自然分布區域으로 하는 海松은 各種因子에 따라 隔離된 集團으로 되어 있다. 內婚의 영향이 있을 것이 짐작되어서 먼저 樹指道의 수를 가지고 地域別로 集團間의 差異를 보아 有意한 差가 인정될 수 있었다. 그리고 同一集團안에 있는 個體間의 有意差도 인정할 수 있었다. 針葉當 수지도의 平均數는 수령에 따라 다르고 어릴때에는 그 數가 적다. 1~14까지의 變域을 보였다. 地域別 또는 個體別을 무시하고 正 및 副樹脂道를 합해서 頻度分布를 公析할 때에는 正規分布에서 이탈한다. 이것은 正樹脂道의 常在性과 副樹脂道의 變異性에 기인하는 것으로 생각된다.

The linear distribution of Pinus thunbergii along the 4 to 8㎞ of southern sea coast in Korea and gradually narrowering towards the eastern and western ends consists of distinct sectional populations, being separated by river, mountain, village and cultivated land. During flowering period, the prevailing wind direction is from the sea and the gene movement is northward, thus the spread in an easterly or westerly directions is prevented. Considering the possibilities of inbreeding. the variations in resin canal numbers per needle section amongst 12 geographic location are analysed. Twenty trees from each location were sampled and 15 needles from each individual tree collected(Fig. 2). In addition, during early August 1966, the senior author collected needle samples of Pinus thunbergii grown on sixteen isolated islands in the southern Korea sea (Fig. 1). The number of individual tree at each location (island) from which needles were collected ranged from 16 to 23 and one needle from each tree was taken. When collecting the needles, effort was made to select these from various parts of topophysis on the tree crown. The results can be summarized as follows: (1) The characteristics of hypoderm, number of resin canals, and the closeness of fibrovascular bundle on needle crass sections were observed under a microscope. (2) Variations in the number of resin canals from different locations and from individual trees were significant(Table 3, 4, 6, and 7, Fig. 2 and 4). Only the number of accessory resin canals provided a bases for recognizing the difference between populations. (3) The average number of resin canal varies with tree age, less when young, i.e., up to 10 years of age. (4) The number of resin canals ranged from 1 to 14. (5) The frequency distribution of resin canal numbers did not follow normal distribution (Fig. 5). If only the accessory canals were taken, they seemed to follow normal distribution. (6) Variations in the number of resin canals among locations seemed due to the chance distribution of gene difference.