Population Genetics in Forestry pp 212-225
Studies on Breeding Structure in Two Tropical Tree Species
- Cite this paper as:
- Sakai KI. (1985) Studies on Breeding Structure in Two Tropical Tree Species. In: Gregorius HR. (eds) Population Genetics in Forestry. Lecture Notes in Biomathematics, vol 60. Springer, Berlin, Heidelberg
Two tropical forest tree species, Altingia excelsa Noronha and Agathis borneensis Warb. were investigated for their breeding structure in natural forests. Assuming that inbreeding would produce higher similarity than random mating in the pattern of isoperoxidase bands in individual trees, the degree of disagreement between trees in isoperoxidase patterns was calculated for estimating occurrence of inbreeding. By finding that trees alike in the isoperoxidase patterns were forming separate groups in the forest in Altingia, five family clumps were presumed (Figure 3). It was found that those different families were dissimilar in respect of isoperoxidase constitution as well as in several leaf characters. The distance between two trees at which they could mate was estimated to be 16 to 18 meters and the area one family occupies 200 to 250 m2 on the assumption that inbreeding in dioecious Altingia should have occurred by consanguineous mating within each family. In spite of growing together of two families within the mating distance, it was found that they showed apparent genetic differentiation between them suggesting that they had been sexually isolated from each other. This sexual isolation, if it happened, is supposed to be due to genetic difference in flowering time.
In Agathis, there was no indication of family clump formation. Thus, the inbreeding effect observed in this monoecious species is supposed to have come from self-fertilization of individual trees.
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