TABOR OAK IN ISRAEL, GENETIC DIVERSITY WITHIN AND BETWEEN POPULATIONS

摘要

Tabor oak (Quercus ithaburensis [Desc.]) is a deciduous and thermophilous species growing at altitudes between 50 to 500 m a.s.l. along the eastern shores of the Mediterranean Sea. It is one of many Mediterranean oaks of which we lack the genetic knowledge necessary for genetic conservation and forest management. We hypothesized that as the result of extensive destruction and fragmentation of the forest area, as a result of human activities, and the existence of a geo-climatic cline, differences in genetic diversity and structure among 16 Q. ithaburensis relict populations in Israel are inevitable. The specific objective of this study was to acquire knowledge on within- and between-populations genetic diversity by means of molecular DNA markers based on PCR methods (RAPD). The results show that total genetic variation (H_t) was 0.4142, Gene diversity within populations (H_s) ranged from 0.329 to 0.396, with an average of 0.3619; and differentiation among populations (G_(st)) ranged from 0.0754 to 0.1056, with an average 0.1263. UPGMA analysis based on genetic distances revealed three main clusters of populations that are coherent with geographic regions of the country: 1 - the Golan Heights and Upper Galilee group, 2 - The Lower Galilee group, 3 -The Mt. Carmel, Samaria and Coastal Plain group. These results support our hypothesis on genetic differentiation of populations according to site geo-climatic conditions.