The influence of Arbuscular mycorrhiza fungi (AMF) (Glomus deserticola and Gigaspora gigantea) were evaluated on drought tolerance and charcoal rot disease of cowpea genotypes: IT90K-277-2, IT84S-2246-4 and IT06K123-1. IT90K-277-2 and IT84S-2246-4 were sown in 3 kg of sterilized soil for drought experiment with five treatments. Treatment was established thirty days after germination with inoculation of G. deserticola, the mycorrhizal treated cowpea withstand the water stress and produced high yield. Biocontrol experiment had 2 kg sterilized soil potted into bags with cultivars IT90K-277-2 and IT06K123-1, fourteen treatments were established with soil drenched before planting and simultaneous inoculation. Soil drenched with AMF before planting and inoculation of M. phaseolina after 10 days of germination recorded higher growth parameters, while the simultaneous inoculated plant was the most effective in reducing disease severity. However, simultaneous treatment of G. deserticola, G. gigantea and M. phaseolina were most effective for both growth parameters and reduction of disease severity.

There is limited information on the genetic response of tomato cultivars to pathogens. This study investigated the genetic mechanism of tomato that confers tolerance against Phytophthora infestans (Ph) and Aspergills niger (Asp) infection using different tomato accessions. Also, the study examined the effect of Ph and Asp infection on the morphology and the chromosome number of the infected tomatoes. Thirty tomato seed accessions were grown in a screen house, using a complete randomized design in triplicate, and evaluated for tolerance to both pathogens using a disease severity rating scale of 1 (highly tolerant) to 6 (highly susceptible), while chromosome assessment was performed using Carnoy’s protocol. Morphological data of 28 characteristics were collected using an IPGRI descriptor, while variance components, genetic advance (GA), and heritability were estimated for treated tomatoes and controls using the R statistical program. Accession NHT0254b, which was highly tolerant to Ph (1.00 ± 0.00) and Asp (1.33 ± 0.58), was diploid (2n = 2x = 24). The Ph-treated NHT0343a was moderately susceptible (3.67 ± 2.31), with 2n = 2x = 23, while NGB00711 was moderately susceptible (4.33 ± 1.16) with 2n = 2x = 22 after Asp treatment, indicating aneuploidy. In Ph treatment, cumulative fruit weight (CFW) had the highest environmental variance (1509.57), while number of seeds (NS) showed the highest genotypic variance (8.22). In Asp treatment, NS exhibited the highest genetic advance (2.97), while CFW had the highest phenotypic variance (754.91). Heritability estimates showed that fruit length (63.0%), the size of core (65.0%), and number of chambers (60.0%) were tolerant to Ph, while only fruit length (56.0%) was tolerant to Asp in terms of yield characteristics. Thus, tolerant accessions and traits are recommended for selection and genetic improvement.

Molecular Variability of Celosia Argentea Using Amplified Fragment Length Polymorphism (AFLP) Marker

This study evaluated the effect of sodium azide-induced mutagenesis on the growth performance of various Capsicum spp accessions. Significant variation was observed across growth traits: number of leaves, leaf length, leaf width, plant height, stem girth, and canopy width. While some accessions, such as NGB00622 and NGB00601, failed to germinate, others exhibited notable performance disparities. NGB00703 emerged as the top-performing accession, excelling across multiple growth traits, followed by NGB002642 and NGB00701. Conversely, NGB02626 and NGB02730 displayed consistently poor growth metrics. Sodium azide-induced variants demonstrated marked improvements in growth traits compared to their controls, particularly in plant height, stem girth, and leaf dimensions. These enhancements were observed not only in high-performing accessions but also in low-performing ones, indicating the mutagen's potential to induce beneficial genetic variability. The findings underscore sodium azide’s utility in generating genetic diversity within Capsicum spp., providing a basis for future breeding and genetic improvement programs.

Celosia argentea is an annual leafy vegetable popularly known for its dietary and medicinal values. Hence, it is important to preserve and further improve this vegetable to enhance its numerous benefits. This study therefore investigated the genetic variability among different genotypes of C. argentea using ISSR primers. A total of 15 C. argentea genotypes were sourced from National Centre for Genetic Resources and Biotechnology (NACGRAB) in Ibadan, Nigeria and 10 genotypes sourced from different markets. The open field experiment was set up in a completely randomized design. Seeds of each cultivar were grown and seedlings transplanted. Fresh young apical leaves were harvested. DNA was extracted from young frozen apical leaves. Six ISSR primers were optimized and used in PCR with a touch-down procedure in a thermocycler. Agarose gel electrophoresis was performed, and bands were visualized. Molecular data was analyzed for total gene diversity, while morphological data was analyzed using ANOVA. The genotypes of NGB recorded the highest mean performance for plant height, leaf biomass and seed weight, while the A00 genotypes were observed to have higher values of leaf length, leaf area and root biomass. The principal component analysis showed that the first component accounted for 42% of the total variation. The correlation matrix for growth, agronomic and yield characters show highly significant positive relationship among the growth characters at P<0.05. Primer UBC-866(CTC)6 was highly polymorphic. Genotype A005 performed best for growth characters while NGB00182 performed best for yield characters. Genetic assessment and improvements in C. argenta germplasm play key role in future studies and improvements of vegetable crop.