A statistical karyotype analysis of European black pine (Pinus nigra Arn.) seed sources

Graduation date: 1983A comparative intraspecific karyotype analysis was performed on European black pine (Pinus nigra Am.) seed sources (countries) by examining root tip meristemic cells of young seedlings (two weeks old). By a combination of Feulgen and Aceto-carmine staining methods, metaphase chromosomes range (12.93 ± 1.33) seedlings from two to three seed collections each of French, Austrian, Yugoslavian, Greek and Turkish seed sources were studied. Variables including chromosome number, short arm length (SL), long arm length (LL), total chromosome length (TL), arm ratio (AR), relative chromosome length (RL), centromere\ud index (CI), morphological index (MI), and secondary constriction and satellite occurrences for each cell were measured. The chromosome number was 2n = 24 for all seed sources. However, aneuploidy 2n = 18 was observed in one seedling of each of the Yugoslavian and Greek seed sources. Analyses of variances for the means of chromosonial variables (F-tests were conducted for the variables SL, LL, TL, CI and MI) indicated\ud that there were significant (P < .05 or P < .01) differences among the seed sources. Chromosomes XI and XII were especially\ud variable among seed sources, with significant (p < .01) variation found for SL, LL, TL, AR, CI and MI. The frequency of secondary constriction occurrences was relatively higher on the long arms of\ud chromosomes and on the longer chromosomes. At low frequency, satellite occurrences were only observed in the Yugoslavian and Greek\ud seed sources, especially on their longer chromosomes. French and Austrian seed sources had only one submetacentric chromosome (chromosome-XII) while the others had two (chromosome-XI and XII). By integrating all the variables measured on all haploid chromosomes, a cluster analysis of the seed collections was performed. Seed sources from Austria and France appear clustered close together, as did Greece and Yugoslavia. The Turkish seed source, however, was the least similar to any of the other sources. Seed collections generally clustered within seed sources