GENETIC-ANALYSIS OF PUNGENCY AND SOLUBLE SOLIDS IN LONG-STORAGE ONIONS

Pungency and soluble solids are important quality attributes of onion. An eight-parent diallel over two years indicated a preponderance of additive genetic variation for both attributes. Variation among years was significant for pungency but not solids. No reciprocal cross differences were noted for pungency or solids. Generation means analysis for four crosses over two years had a good fit with a simple additive-dominance model to explain the inheritance of both traits in most cases. Both diallel and generation means analyses demonstrated some dominance for low pungency. Broad sense heritability estimates averaged 0.64 for pungency and 0.83 for soluble solids. Selection was effective for increasing and decreasing pungency in derivatives of five crosses. Pungency and soluble solids were correlated among parental inbreds and hybrids but not within F-3's. The additive control and heritability suggest that onion pungency and soluble solids can be effectively and independently selected.