Orman ağaçlarında eşleşme şekilleri

Orman ağaçlarında yaşayabilir nitelikteki tohumlar başlıca üç farklı tipteki döllenme (eşleşme) sonucu oluşur: kendi-kendine döllenme, aynı lokal populasyon içinde farklı bireyler arasındaki döllenme ve lokal populasyon dışındaki bireylerden gelen polenlerle döllenmedir. Kozalaklı orman ağacı (konifer) türlerinde eşleşme şekli konusunda yapılan çalışmalar son yıllarda hızla artmaktadır. Klonal tohum bahçelerinde kendinden-başka-bireylerle döllenme sonucu oluşan tohumların yarısından fazlası tohum bahçesi dışındaki bireylerden gelen polenler (yabancı gen akımı) sonucu oluşmaktadır. Doğal populasyonlarda ise oluşan tohumların, ne oranda kendi-kendine döllenme sonucu, ne oranda aynı populasyon içindeki farklı bireyler arasındaki döllenme sonucu, ne oranda gen akımı sonucu oluştuğu konusunda yeterli bilgi bulunmamaktadır. Bu makalede, koniferlerde eşleşme modelleri ve eşleşme sistemiyle ilgili parametrelerin, genetik markırlar (belirteçler) yardımıyla belirlenmesi konusunda bilgiler verilmektedir.

Anahtar Kelimeler:

izoenzimler, orman ağaçları, gen akışı

Mating patterns in forest trees

Viable seeds in a population of forest trees result from three types of fertilization: selfing, outcrossing among different individuals within the same local population, and outcrossing with the mates outside the local population. Research on mating patterns in forest trees has been accelerated in recent years. In clonal seed orchards, more than half of cross-fertilized seeds are due to pollens coming from outside sources (gene flow). In natural populations, however, there is no enough information as to the proportions of viable seeds resulting from either selfing, cross-fertilization among different individuals within a local population, or foreign gene flow. This article presents information on how mating patterns and related parameters in conifer species could be determined through genetic markers.

Keywords:

isoenzymes, forest trees, gene flow,

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