A method is described for isolating mitochondria from nodules of cowpea (Vigna unguiculata [L.] Walp.) under completely anaerobic conditions. The mitochondria were immediately active when incubated aerobically with substrates, and their respiration rates were higher than mitochondria prepared in air. The mitochondria lacked fumarate reductase and were not inhibited by 5% CO(2). When incubated u...

Yardlong bean (Vigna unguiculata subsp. sesquipedalis) plants with virus-like systemic mottling and leaf distortion were observed in both experimental and commercial fields in Aragua State, Venezuela. Symptomatic leaves were shown to contain carlavirus-like particles. RT-PCR analysis with carlavirus-specific primers was positive in all tested samples. Nucleotide sequences of the obtained ampli...

Dehydrins (DHNs, LEA D-11) are plant proteins present during environmental stresses associated with dehydration or low temperatures and during seed maturation. Functions of DHNs have not yet been defined. Earlier, we hypothesized that a approximately 35-kDa DHN and membrane properties that reduce electrolyte leakage from seeds confer chilling tolerance during seedling emergence of cowpea (Vigna...

The economy of C and N in nodulated cowpea (Vigna unguiculata [L.] Walp.) was described in terms of fixation of CO(2) and N(2), respiratory losses of C, and the production of dry matter and protein.Net daytime gain of C by the shoot (net photosynthesis) rose to a maximum at flowering and then declined sharply due to abscission of leaves. Maximum N fixation occurred 10 days prior to maximum net ...

Previous genetic studies in cowpea [Vigna unguiculata (L.) Walp] have shown that an active bipartite transposable element (TE) is responsible for a range of mutant phenotypes of its leaf, stem and flower. Since type II TEs have not been characterized at the molecular level in cowpea, this study was initiated to survey the presence of type II TEs in the cowpea genome. Type II TEs: Enhancer/Suppr...

A concentration as low as 1 microM lead (Pb) is highly toxic to plants, but previous studies have typically related plant growth to the total amount of Pb added to a solution. In the present experiment, the relative fresh mass of cowpea (Vigna unguiculata) was reduced by 10% at a Pb2+ activity of 0.2 microM for the shoots and at a Pb2+ activity of 0.06 microM for the roots. The primary site of ...

Cowpea bruchid is a major constraint to cowpea production. Easy identification of resistant/tolerant accessions infestation has been challenge in resistant breeding programmes. Hence, the study was aimed evaluate variations some morphological characters between and susceptible accessions, correlating them with their tolerance status hope identifying pointer character(s) that can facilitate easy...

The effect of some processing techniques (germination boiling and dehulling) on the soluble sugar contents and the emulsion property of processed flour were studied. Results show that germination significantly reduced the raffinose level from the third to the fifth day sprouting period (P<0.05). Boiling and dehulling also reduced the content of this flatus oligosaccharide (raffinose) but not to...

Mitochondria were isolated from nodules of cowpea (Vigna unguiculata (L). Walp.) and purified on a Percoll gradient. They were only slightly contaminated by bacteroids (an average of 3.5%), and had low lipoxygenase activity. Compared to mitochondria from hypocotyls the nodule mitochondria had similar O(2) uptake rates and respiratory control ratios. The ADP/O ratios for both preparations were 1...

Five greenhouse-grown cowpea [Vigna unguiculata (L.) Walp] cultivars were tested in a generalized random complete-block design to determine the effect of early leaf harvest on dry weight and protein concentration of plant parts at maturity. The most recent, fully expanded leaves on each branch from one group of plants were harvested at 5 and 7 weeks after planting. On the other groups of plants...