QUANTITATIVE GENETIC DIVERSITY ACID CONSERVATION STRATEGIES FOR AN ALLOGAMOUS ANNUAL SPECIES, DASYPYRUM-VILLOSUM (L) CANDARGY (POACEAE)

Dasypyrum villosum (L.) Candargy is a weedy annual diploid (2n = 14, V V genomes) allogamous grass species (Poaceae, Triticeae). Genetic vari ation for 12 traits was studied in 43 natural populations (31 from Ita ly and 12 from Croatia and Montenegro of former Yugoslavia) grown in a common field environment in California. Although 7 of12 traits follow ed the theoretical prediction that a larger proportion of genetic vari ation was distributed within populations than among populations, excep tions were found for spike length, plant height, and days to flag-leaf emergence, heading, and anthesis. Covariate analysis showed that deve lopmentally closely related characters were more likely correlated at both population and family within population levels. Geographically cl oser populations shared more genetic similarity than distant populatio ns as indicated by mean coefficients of variation and cluster analysis of the Euclidean distances among populations. As few as five populati ons, each population with five or more half-sib seeds taken randomly f rom 5 plants, is expected to capture more than 95% of the total geneti c variation of this species in the region sampled, but sampling a much larger number of seeds per population (> 1000) for long-term storage would supply research and plant breeding needs for several decades. If seed regeneration is required, populations can be sampled from cluste rs having similar genetic variation, and grown in reproductive isolati on or bulked seed samples from all populations of each cluster group c an be grown in isolation. The former is recommended if population inte grity is desired while the latter is sufficient to provide genetic res ources for plant-breeding purposes.