Total phenolics and condensed tannins in field pea (Pisum sativum L.) and grass pea (Lathyrus sativus L.)

Abstract

Seed samples of seventeen field pea cultivars grown at five locations, and nine grass pea lines grown at two locations, in western Canada during 1993 and 1994 were analysed for total phenolics and condensed tannins. Each location in each year was considered as one environment. Total phenolics in field pea differed significantly among cultivars, ranging from 162 mg/kg DM (dry matter) (CE, catechin equivalents) for AC Tamor to 325 mg/kg DM (CE) for Richmond. Field pea had barely detectable levels of condensed tannins. Total phenolics in grass pea ranged from 868 mg/kg DM (CE) for L880388 to 2059 mg/kg DM (CE) for LS89110. Condensed tannins in grass pea ranged from 0.89 g/kg DM (CE) for L880388 to 5.18 g/kg DM (CE) for LS89125. Cultivar had a larger relative contribution to total phenolic levels in field pea and to total phenolic and condensed tannin levels in grass pea than environment. Total phenolic and condensed tannin levels were not correlated with seed yield and seed protein content in field pea or grass pea. Levels of total phenolics and condensed tannins were positively correlated in grass pea. Grass pea seeds with darker seed coat colour contained higher levels of condensed tannins.