Site influences on the genetic variation and structure of Pinus halepensis Mill. provenances
2001
Korol, L. | Shklar, G. | Schiller, G. (The Volcani Center, Bet Dagan (Israel). Agricultural Research Organization)
We tested whether the F1-offsprings rose from seeds collected in natural native Israeli and overseas populations of Pinus halepensis Mill. planted under semi-arid environmental conditions exhibit genetic diversity and structure similar to those of their parental origin populations. Allele frequencies and genotypes of trees that had survived since planting 15 years ago, and those in the natural populations of origin were determined by means of starch gel electrophoresis technique. Use was made of the haploid megagametophyte tissue of the pine seeds. The percentage of polymorphic loci increased from an average of 40 % in the natural populations to 46% in the progenies, and the average observed heterozygosity rose from 0.118 to 0.167. The largest changes in diversity, heterozygosity and fixation index occurred in the population that had originated in the highest and wettest environment, whereas only minor changes occurred in a population that had originated in a relatively drier environment. Dry-land afforestations in places outside the natural distribution area of a species can be looked upon as peripheral populations with their higher genetic diversity conferred by selection, and thus having more resistance to extreme conditions. Therefore, such afforestations should be treated as a biogenetic resource available for rehabilitation and restoration of damaged Aleppo pine ecosystems
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