ARS | Publication request: GENETIC DIVERGENCE IN A META-POPULATION OF THE HOURANI DURUM WHEAT LANDRACE

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2004
Publication Date: November 4, 2004
Citation: Jaradat, A.A. 2004. Genetic divergence in a meta-population of the Hourani durum wheat landrace [CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. Madison, Wisconsin.

Technical Abstract: The Hourani durum wheat landrace was cultivated for millennia in the Houran plateau of northern Jordan and southern Syria. Recently however, it became highly fragmented due to the introduction of high yielding varieties. Its genetic divergence was assessed in 289 populations collected from ten villages in four ecogeographical regions in both countries. Ten agronomic and 10 polymorphic qualitative descriptors in addition to polymorphism at two high-molecular-weight (HMW) glutenin loci were used in this study. Polymorphism in agronomic traits was apportioned among populations (13.54%), among villages (56.39%), among ecogeographical regions (21.05%) and among countries (9.02%). The respective values for qualitative descriptors were 8.23, 20.74, 47.95 and 23.08%. Population differentiation at the HMW glutenin loci was 24.85% for the whole collection and no significant differences were detected among or within countries. Geographical distances among villages were correlated with genetic distances based on agronomic (r=0.59, p=0.05) and qualitative (r=0.43, p=0.08) traits; genetic distances of the last two, however, were highly correlated (r=0.92, p=0.000). Based on agronomic traits, only 20% of the populations had all 10 principal components (CPCs) in common; almost half (53.0%) shared six-eight, whereas the remaining 27% shared zero-three CPCs. Average correct classification of germplasm by country (82.0%), region (70.0%) village (51.0%) and population (35.7%), based on the discriminant power of different agronomic traits and trait combinations, confirms the existence of a highly divergent germplasm in this landrace.