Understanding the relative contributions of genetic and environmental effects is essential for effective crop improvement. This study evaluated 38 cassava genotypes across multiple locations to assess genetic variability, genotype × location interaction (G×L), and selection efficiency for agronomic, yield, and quality traits. Analysis of variance revealed significant genotypic effects for cassava green mites, cassava mosaic disease, vigor, plant height, and all yield and quality traits (P < 0.001), indicating substantial exploitable genetic variation. Location effects were highlysignificant for all traits, confirming strong environmental influence, particularly on growth, dry matter content (DMC), and yield. Significant G×L interactions occurred for cassava bacterial blight, cassava green mites, cassava mosaic disease, arch, and DMC, indicating differential genotype responses across environments. In contrast, vigor, plant height, fresh root yield, fresh shoot weight, and harvest index showed relatively stable performance. Phenotypic coefficients ofvariation exceeded genotypic coefficients for all traits, confirming environmental effects. Broadsense heritability ranged from moderate (0.33 for DMC) to very high (0.94 for plant height). High heritability and genetic advance for plant height, fresh root weight, and fresh shoot weight indicated strong selection potential, whereas lower estimates for dry yield and DMC suggested greater environmental or non-additive effects. Principal component analysis showed that yieldtraits contributed most to PC1, while quality and resistance traits were associated mainly with PC2. A multi-trait selection index identified superior genotypes combining high yield, acceptable DMC, vigor, and low CMD severity. Overall, integrating multi-environment testing, genetic parameters, multivariate analysis, and selection indices can accelerate genetic gain and support the development of broadly adapted, high-performing cassava cultivars.
The sole prospect for a sustainable identification capability lies in the construction of systems that employ DNA sequences as Taxon barcodes. Clarification of phylogenetic relationships of rice species is critical for effective utilization of the rice germ plasm. To make adequate classification we obtained DNA sequences of a chloroplast gene. The sequence of 2,455 base pair of the large sub-unit of riboluse-b-phosphate carboxylase gene (rbcl) was determined fromthree species of rice; Faro 44, 52, and 60 respectively. Phylogenetic trees were inferred by the neighbor joining method and the trees produced topology that provided insights concerning the general evolutionary trends in the Oryza. The rbcl species profile was 100% successful in identifying the rice verities, the phylogeny revealed the presence of domestication of two rice species; Asian rice (Oryza sativa) and African rice (Oryza glaberrima). Other varieties (Faro52 and 60) formed a monophyletic clade in line with Zhang etal, (2020) who reported that haplotyptes of the same genome types formed monophyletic clades. However, faro 44 rather formed a paraphyletic clade and is supported up to 100% in boostrap value-indicating that they shared the same maternal parent from the AA genome type. Unique taxa tend to differ at the nucleotide level, due to a few mutations. Evolutionary divergence values were generally low (0.0018 – 0.4899). Morphological characteristics should be evaluated as being phylogenetically informative and will be pertinent to estimating the phylogenetic position of extinct/ mutagenically affected DNA sites. In addition, further studies will be needed to examine the origin and speciation of some glaberrima seen in the phylo-tree.
The study investigated the effect of different substrates (log of dead wood (LDW); a mixture of rice husk and sawdust (RH+SD) on the chemical compositions of oyster mushroom (Pleurotus ostreatus). The mushroom samples were prepared in flour, and their proximate, mineral, vitamin, antioxidant, and antinutrient compositions were analysed using standard methods. The data obtained were analysed using an Independent T-Test at a 5 % level, revealing significantdifferences (p<0.05) in the values of proximate, mineral, vitamin, antioxidant, and antinutrient contents of the oyster mushroom. LDW-grown mushroom had higher protein (23.47 %) and fibre (15.51 %), while RH+SD-grown mushrooms had higher ash (8.01 %) and carbohydrate (56.36 %). LDW and RH+SD-grown mushrooms had higher magnesium (7.97 mg/100g) and calcium (4.97 mg/100g); zinc (7.97 mg/100 g) and iron (7.38 mg/100 g), respectively. Similarly, RH+SD and LDW-grown mushrooms had higher concentrations of vitamin A (4.23 mg/100g), vitamin D (216.82 mg/100 g) and vitamin E (4.08 mg/100 g), respectively. Antioxidant levels indicated that RH+SD-grown mushrooms had higher flavonoid (2.01 %) and total phenolic content (22.75 mg/100 g), while LDW had higher beta-carotene (13.39 mg/100 g). LDW-grown mushroom also had higher trypsin inhibitor (11.19 mg/100 g) and haemagglutinin (3.26 mg/100 g), while RD+SDgrown mushrooms had higher phytate (38.54 mg/100 g). These findings highlighted that substrates have significant effects on the chemical compositions of oyster mushroom, which offer promising nutritional and health benefits, supporting sustainable food production and dietary supplementation. Incorporating both LDW and RH+SD-grown oyster mushrooms into diets to provide a range of nutritional benefits while also supporting sustainable food production practices is highly recommended.
Saturated hydraulic conductivity (Ksat) is an important indicator of soil physical quality, influencing water infiltration, drainage, runoff, groundwater recharge, and nutrient movement. This study evaluated the effects of selected soil physical properties on Ksat under five contrasting land-use systems in Imo State, southeastern Nigeria. Five communities which includes, Agbala, IMSU, Orogwe, Umuelu Ohaji, and Umueze Ohaji were selected, with five land uses (cassava farmland, secondary forest, oil palm plantation, plantain plantation, and block industry) assessed in each community. Composite and undisturbed soil samples were collected at 0–15 and 15–30 cm depths using a Completely Randomized Design with three replications. Particle size distribution, bulk density, total porosity, moisture content, and Ksat were determined using standard laboratory procedures. Data were subjected to analysis of variance, Duncan’s Multiple Range Test, Pearson correlation, and regression analysis. Results showed significant (P < 0.05) variations in soil physical properties and Ksat across land uses and depths. Plantain plantations and secondary forests generally recorded higher moisture content, lower bulk density, greater porosity, and higher Ksat than oil palm plantations and block industry sites. Correlation results indicated weak to moderate relationships between Ksat and individual soil properties, suggesting that hydraulic conductivity was controlled by the combined effects of texture, bulk density, porosity, soil structure, and pore continuity. Vegetation-based land uses promoted better soil structure and water transmission, whereas intensive disturbance increased compaction and reduced hydraulic performance. The findings emphasize the need for sustainable land management practices that maintain vegetation cover, improve organic matter, and minimize soil disturbance to enhance soil hydraulic functioning and agricultural productivity in humid tropical environments.
Cassava (Manihot esculenta Crantz) productivity is strongly influenced by genotype × environment interaction (G × E), which complicates the identification of superior and stable genotypes for cultivation across diverse environments. This study evaluated fifteen cassava accessions across three environments using combined analysis of variance (ANOVA) and the Additive Main Effects and Multiplicative Interaction (AMMI) model to determine the effects of genotype, environment, and their interaction on agronomic and quality traits. Traits assessed included root number, shoot weight, total root weight, fresh root yield (FRY), dry yield, dry matter content (DMC), starch content, and harvest index (HI). Combined ANOVA revealed significant genotypic variation for root number, shoot weight, total root weight, DMC, starch content, and HI, indicating the presence of exploitable genetic variability among accessions. Environmental effects significantly influenced shoot weight, total root weight, FRY, DMC, starch content, and HI, demonstrating the importance of environmental conditions in trait expression. Genotype × environment interaction was significant for FRY and DMC, suggesting differential genotype responses across environments, but was non-significant for root number, shoot weight, total root weight, starch content, and HI, indicating relatively stable performance for these traits. AMMI analysis identified F22P001 as the highest-yielding genotype (19.62 t ha⁻¹), although it exhibited low stability (ASV = 1.81). Conversely, F135P001 and F9P0002 were the most stable genotypes (ASV = 0.54). TMEB7 combined desirable yield performance (11.47 t ha⁻¹) with good stability (ASV = 0.65), making it a promising genotype for broad adaptation. The findings highlight the value of integrating yield, quality, and stability assessments to enhance cassava breeding andcultivar recommendation across diverse agroecological environments.
