A symbiont, isolated from root nodules of Crotalaria saltiana Andr., was identified as Rhizobium sp. It produced large amount of extracellular polysaccharides (EPS) in broth culture in yeast extract mannitol (YEM) medium. The EPS production and growth started simultaneously, though they have different stationary phases. The symbiont produced maximum EPS (16 μg/mL) when the medium was supplement...

During a 6-year study of 1-, 2-, and 3-year crop rotations, population densities of Pratylenchus brachyurus, Trichodorus christiei, and Meloidogyne incognita were significantly affected by the choice of crops but not by length of crop rotation. The density of P. brachyurus and T. christiei increased rapidly on milo (Sorghum vulgate). In addition, populations of P. brachyurus increased significa...

Crotalarias are tropical legumes grown as cover crops or as green manure to improve soil fertility. As an understory plant in plantation systems, these cover crops receive low levels of irradiance and are subjected to elevated levels of CO2 and temperatures. A greenhouse experiment was conducted to evaluate the independent short-term effects of photosynthetic photon flux density (PPFD), externa...

Legumes of the genus Crotalaria contain appro ximately 550 species dispersed throughout the world, the great majority well adapted to the tropical climate. Only a limited number occurs in temperate regions. They are annual erect herbs or woody shrubs, originated from India, Africa, and Madagascar, and have been used in the paper and animal feed industry as a source of fi bers and silage, in gre...

Infection of legume hosts by rhizobial bacteria results in the formation of a specialized organ, the nodule, in which atmospheric nitrogen is reduced to ammonia. Nodulation requires the reprogramming of the plant cell, allowing the microsymbiont to enter the plant tissue in a highly controlled manner. We have found that, in Crotalaria (Fabaceae), this reprogramming is associated with the biosyn...

When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high re...