CURRENT STATUS AND FUTURE STRATEGY IN BREEDING PEA TO IMPROVE RESISTANCE TO BIOTIC AND ABIOTIC STRESSES

The economic importance and current progress made in studies of the ho st-parasite relationship and identification of sources of resistance a nd breeding strategies of some important biotic diseases of pea are re viewed in this paper. The root rot complex caused by Rhizoctonia solan i, Fusarium solani, Aphanomyces euteiches, Pythium ultimum and Fusariu m oxysporum f. sp. pisi, race 1 and 2 has been reported from all comme rcial pea growing areas of the world. Adequate sources of resistance h ave been identified and there has been impressive success in the contr ol of the Fusarium wilt pathogen following the introduction of wilt-re sistant cultivars. Leaf and stem diseases of pea caused by the Ascochy ta complex, Peronospora viciae and Erysiphe pisi are prevalent in most temperate pea growing regions of the world. Several sources of resist ance are available, some of which are surprisingly durable. The bioche mical genetic parameters of phenolic content used for assaying resista nce to Erysiphe pisi offers an alternative method of evaluating breedi ng material. Wild relatives of pea (Pisum fulvum and P. humile) are va luable additional sources of genetic variation and provide good source s of resistance to pests and diseases. In temperate rainfed pea growin g areas of southern Australia, pea seed yield is more closely related to dry matter production than harvest index. Tall and leafy cultivars proved more productive than afila types.