Regeneration of plants from protoplast of winged Bean (Psophocarpus tetragonolobus L. DC.)

Abstract

The winged bean (Psophocarpus tetragonolobus L. DC.) has been traditionally grown as a backyard crop by subsistence farmers in the humid tropics of Southeast Asia and the West Pacific. They harvest the characteristic long four-winged pods when they are immature and use them as a green vegetable. In addition, ripe seeds are sold in local markets, whereas the green leaves and dried haulms are frequently used as animal feed. The properties and uses of the winged bean have recently been reviewed by Valicek (1989). In 1975 the features of the winged bean were brought to the notice of a wider range of agriculturists and scientists by the publication of a report of a special panel of the US National Academy of Sciences entitled “The winged bean, a high protein crop for the humid tropics”. Analysis revealed that the seed is similar in composition to soybean and the ripe seed can be processed to yield a milk, which is said to taste better than soy milk. The leaves are high in protein and vitamin A and can be eaten rather like spinach, and young shoots can be used like asparagus. Furthermore, some accessions produce substantial tubers, which are rich in protein and can be milled to produce a flour. The fact that the winged bean can nodulate in association with Rhizobium to fix nitrogen, thus dispensing with the need for expensive nitrogenous fertilizer, is a further major attribute. Recognition of the value of the winged bean has prompted efforts to extend the area of cultivation from the hill regions of Burma, India, and Papua New Guinea to other suitable regions.