Ideotypes of forage pea (pisum sativum) cultivars

Abstract

Pea (Pisum sativum L.) is one of the most important grain legume crops in temperate regions worldwide. In many countries of Europe, West Asia and North Africa, it is also used in feeding ruminants in the form of fresh forage, forage dry matter, forage meal, silage, haylage and straw. The goals of breeding pea for forage significantly differ from those in breeding pea for grain. A large majority of currently ongoing breeding programmes on forage pea develop cultivars completely or mostly from local or introduced populations of P. sativum L. subsp. sativum var. arvense (L.) Poir. Such cultivars are characterised by long stems with indeterminate growth, long internodes, great number of nodes, large stipules and three pairs of leaflets, purple flowers and low seed yields in comparison to typical feed pea cultivars. They also have prominent winter hardiness, late maturity and large forage losses due to an extremely poor lodging tolerance, being the reason why these cultivars are mostly grown intercropped with cereals. Much of said traits, such as large aboveground biomass resulting from long stems or large leaves are important segments of the ideotypes of a forage pea cultivar. More recent improvements include determinate stem growth and moderately great stem length, in order to reduce withering of at least a whole lower half of leaves on the plant, as well as a leaf proportion in the aboveground biomass higher than 0.50, improved earliness and a forage dry matter proportion of about 0.25, increasing crude protein content and decreasing both neutral and acid detergent fibre and lignin content in forage dry matter. A successful combination of all these desirable traits may result in a forage pea cultivar producing about or slightly more than 10 t ha−1 of forage dry matter and about 2 t ha−1 of forage crude protein, able to easily fit into diverse cropping systems. The latest trends in forage pea cultivars brought forth the first semi-leafless cultivars with excellent standing ability and enhanced seed production, where numerous and large stipules successfully replace the missing leaflets in providing quality forage.