AFLP-based genetic diversity assessment among wheat cultivars from the Pacific Northwest

Assessing genetic diversity among adapted, elite germplasm may expedite crop improvement. The objectives of this study were to (i) assess genetic diversity among a representative sample of spring and winter wheat (Triticum aestivum L,) cultivars adapted to dryland production in the Pacific Northwest by amplified fragment length polymorphisms (AFLPs), and (ii) compare genetic diversity estimates (GDEs) generated by methylation sensitive and methylation insensitive restriction enzymes for AFLP analyses, Fifty-four cultivars and two diploid relatives were included in the study. Sixteen AFLP primer pairs detected 229 polymorphic bands. Mean GDEs (0.51 and 0.58, respectively) detected by PstI:MseI (methylation sensitive) and EcoRI:MseI (methylation insensitive) AFLP analyses were significantly different (P < 0.0001), indicating greater diversity was detected for methylated sequences. Mean GDEs, based on data from both restriction enzyme combinations, were highest (0.58) for spring vs. winter type pairwise comparisons, intermediate (0.53) within winter type, and lowest (0.49) within spring type. Cluster analysis, ordination analysis, and the analysis of molecular variance suggested genetic diversity among cultivars was hierarchically arranged as cultivars nested within market class, and market classes nested within growth habit. AFLP analysis is an efficient technology for assessing genetic diversity among wheat cultivars.