CONTROL OF SEED PROTEIN ACCUMULATION IN FIELD BEAN (VICIA-FABA L)

A study was made of the changes during development in the total amino acid and dopa content of bean pod phloem sap, employing EDTA to aid phloem exudation. Two field bean lines, Dacre B and D, selected for their low and high seed protein content, respectively, were compared. Throughout development, the sap samples of Dacre D had a greater amino acid concentration than those from Dacre B. The sap of Dacre B contained a higher proportion of dopa than that of Dacre D. These 2 lines of Dacre were also studied with respect to accumulation of protein and uncombined amino acid in cotyledons grown in both in vitro and in vivo. Dacre D accumulated more total protein than Dacre B but contained a similar amount of uncombined amino acids when grown in vivo. However, the amount of total protein accumulated was similar when the cotyledons were grown in vitro. The supply of nutrients to the pod may be the basis of the different protein concentrations in the mature seed of these lines.