Identification of new sources of resistance to Striga gesnerioides in cowpea Vigna unguiculata accessions

Abstract

The parasitic weed, Striga gesnerioides, is a major threat to cowpea productivity throughout the savannas of West and Central Africa. The identification of sources of S. gesnerioides resistance and their incorporation into breeding programs would be a beneficial strategy to combat the devastation caused by the parasite in cowpea fields. In this study we examined one hundred and ninety-four (194) accessions, four commercial varieties and two controls collected from a mini core collection of cowpea held at the International Institute of Tropical Agriculture genebank for resistance to S. gesnerioides race 3 (SG3), the most prevalent race in Nigeria, using phenotypic screening and molecular marker analysis. Our studies identified two cowpea accessions, Tvu-1272 and Tvu-16514, that are resistant to S. gesnerioides SG3. Resistance in these lines is associated with the molecular marker SSR1, known to segregate with the gene conferring resistance to SG3 in the cultivar B301. Phenotypically, resistance in Tvu-1272 and Tvu-16514 is expressed as a hypersensitive response at the site of infection on the roots. Allelism tests indicated that the gene that conferring SG3 resistance in Tvu-1272 is independent of that conferring resistance in B301. Tvu-1272 and Tvu-16514 will provide additional new sources of resistance to Striga and races prevalent in Nigeria.

Screening of cowpea (Vigna unguiculata (L.) Walp.) lines for resistance to three Aphids (Aphis craccivora Koch) strains in Burkina Faso

“…These results are in accordance with those of Laamari et al (2008); Obopile and Ositile (2010) and Aliyu and Ishiyaku (2013). The difference among lines with regard to the area under the infestation progress curve is due to the capacity of some lines to slow down the development and multiplication of aphids by "antibiosis" (Teetes, 2007;Alabi et al, 2012;Omoigui et al, 2017). Thus, IT97K-556-6 has exhibited the highest level of antibiosis.…”

Screening for resistance to Striga gesnerioides and estimation of yield loss among Cowpea (Vigna unguiculata (L.) Walp.) progenies in the Upper East Region of Ghana

“…Parasitic plants are a major constraint to today"s agriculture with most crop species being potential hosts (Westwood et al, 2010). Striga gesnerioides, is a key threat to cowpea production throughout West and Central Africa (Omoigui et al, 2017). It is one of the greatest devastating parasitic weed in most parts of the world.…”

“…In general, S. gesnerioides control is difficult to achieve due to the close association with its host (Lane et al, 1997). The identification of sources of S. gesnerioides resistance and their incorporation into breeding schemes would be a useful approach to combat the damage caused by the parasite in cowpea fields (Omoigui et al, 2017).…”

Tracking agronomic diversity in land races of cowpea [Vigna unguiculata (L.) Walpers] collected from Pakistan

“…For strengthening gene pool one way is to collect material from geographically diverse origins from proposed centers of diversity in case of individual samples. Authentic samples from the complete geographical range of the crop species can help maintaining conservation of co-adapted genes [13][14][15]. Cowpea is an important summer pulse crop and widely cultivated under rainfed areas.…”