Relationships between seed yield and chemical composition of field peas grown under semi-arid Mediterranean conditions

Relationships between seed protein, lipid, starch and sugar concentrations and seed yield of 14 pea (Pisum sativum L.) cultivars were examined under rain-fed conditions in northern Jordan. Significant differences amongst cultivars for each character were noted. The cultivar-by-environment interaction was significant for each character except lipid and starch concentrations. A negative correlation was noted between seed yield and seed protein and fructose concentrations. Positive nonsignificant correlations between seed yield and seed lipid and starch concentrations were noted. The cultivars DMR-8, P 350-1 and 8SP022-6 had similar seed yields, but varied seed chemical components. Seeds of the Praire No. 11 cultivar had the highest protein concentration amongst cultivars, although it produced the lowest seed yield. These results indicate that factors other than seed yield are important for determining the chemical composition of seeds, and that one-sided selection for high seed yield tends to reduce the nutritional quality of the pea seed.