A STUDY OF GENETIC DIVERSITY IN POPULUS-NIGRA SUBSP BETULIFOLIA IN THE UPPER SEVERN AREA OF THE UK USING AFLP MARKERS

A survey of amplified fragment length polymorphism (AFLP) was conducte d to examine genetic diversity in 146 individuals of British, native b lack poplar (Populus nigra subsp. betulifolia) and three individuals c onsidered by collectors to be non-betulifolia poplars. Using two prime r pairs, a total of 147 bands were detected of which 82 (56%) were pol ymorphic in at least one individual. Cluster analysis and principal co ordinates analysis of the calculated similarity matrix revealed a low level of genetic diversity, although a loose clustering into five grou ps could be identified, one of which contained the non-betulifolia ind ividuals. Examination of the spatial distribution of the other four gr oups (all betulifolia) revealed a general correlation between geograph ic proximity and genetic similarity. On the basis of the polymorphism observed, it was possible to identify a small number of individual pla nts which exhibit maximum diversity and might therefore be suitable fo r inclusion in a replanting programme designed to maintain at least th e existing low level of polymorphism observed within British black pop lar.