To understand the genetic mechanism of host specificity in the interaction between rhizobia and their hosts, it is important to identify genes that influence both early and late steps in symbiotic development. This paper focuses on the little-understood genetics of host-specific nitrogen fixation. A deletion mutant of Bradyrhizobium japonicum, strain NAD163, was found to induce effective, nitro...

Zabrotes subfasciatus larvae possess three alpha-amylase isoforms as determined by in gel assays following SDS-PAGE. The two minor isoforms present lower electrophoretic mobility than the major form, and seem to occur as a heterodimer. When developed inside Vigna unguiculata (cowpea) seeds, fourth instar larvae have minor quantities of the slow-migrating forms, but when reared on seeds of Phase...

Eleven isolates of cowpea severe mosaic virus (CPSMV), a member of the genus Comovirus, were selected from 50 samples collected of nine cowpea fields in Northeastern Brazil (Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe, Bahia, and Distrito Federal) and partially sequenced. The RNA1 partial sequence, corresponding to the helicase, viral genome-linked protein, pic...

The root knot nematodes (RKN), Meloydogine spp., particularly Meloidogyne incognita and Meloidogyne javanica species, parasitize several plant species and are responsible for large annual yield losses all over the world. Only a few available chemical nematicides are still authorized for RKN control owing to environmental and health reasons. Thus, plant resistance is currently considered the met...

The use of microorganisms to improve the availability of nutrients to plants is of great importance to agriculture. This study aimed to evaluate the effect of triple inoculation of cowpea with arbuscular mycorrhizal fungi (AMF), plant growth-promoting bacteria (PGPB) and rhizobia to maximize biological nitrogen fixation (BNF) and promote plant growth. The experiment was conducted in a greenhous...

Male sexual aggregations are a common territorial, mating-related or resource-based, behaviour observed in diverse organisms, including insects such as thrips. The influence of factors such as plant substrate, time of day, and geographic location on aggregation of thrips is uncertain, therefore we monitored the dispersion of male and female bean flower thrips (BFT), Megalurothrips sjostedti (Tr...

Isofemale lines (IFL) from single egg masses were studied for genetic variation in Meloidogyne incognita isolates avirulent and virulent to the resistance gene Rk in cowpea (Vigna unguiculata). In parental isolates cultured on susceptible and resistant cowpea, the virulent isolate contained 100% and the avirulent isolate 7% virulent lineages. Virulence was selected from the avirulent isolate wi...

in order to evaluate the competitive ability of legume cover crops on interference of weeds in corn, an experiment was carried out in sari agricultural sciences and natural resources university during 2011 growing season. this research was carried out based on complete block design with three replications. treatments consisted of three cover crops including: soybean (glycine max l.), fenugreek ...

Water deficit and phosphate (Pi) deficiency adversely affect growth and biological nitrogen fixation (BNF) of legume crops. In this study, we examined the impact of interaction between soil water conditions and available soil-Pi levels on growth, nodule development and BNF potential of nine cowpea varieties grown on dry savanna soils. In our experimental design, soils with different available s...

to study the effect of strip intercropping pattern with cowpea and soybean on sorghum fodder yield an experiment was conducted at research farm of university of tehran (karaj) during 2005. the experiment was arranged in a randomized complete block design of four replications. the plant proportions included pure culture of sorghum (sss); cowpea (ccc) and soybean (ggg) each in 12 rows; vs differe...