Current Issues

ABSTRACT: Hairiness on cowpea pods is a morphological obstruction to piercing and sucking insect pests. Possession of this attribute will afford a healthy pod that can translate to healthy grains, thus, improving grain yield per hectare. Breeding experiments were conducted in Bauchi environment between 2015 and 2018 to study the inheritance of pod hairiness in Cowpea. Thirty genotypes of cowpea obtained from collections and hybridisation trials were evaluated using complete randomised block design with three replications. The results showed that hairiness on cowpea pods was dominant in all the F1 crosses. Segregation pattern of 3:1, a monogenic inheritance, was observed in all the F2 crosses, except for Achishiru x Wild and NGB 00765 x Wild where there was no segregation, because both had similar pod attributes with the wild. The segregation pattern obtained in this study implies that pod hairiness is a heritable trait and can be transferred easily from the wild to the cultivated landrace cowpeas, where selection for the trait can be achieved on early segregating generations for improved and sustainable grain yield.

Keywords: Cowpea genotype, Landrace, Inheritance, Pod hairiness, Agroecology.

ABSTRACT: Cassava is an important staple, food security, income-generating, and industrial crop in Nigeria. Despite its importance, cassava production in North-east and North-west faces challenges such as limited information on the genetic diversity of available accessions. Field experiment was conducted during 2022/2023 growing season with the aim to assess the extent and pattern of genotypic variation among cassava accessions cultivated in North-west and North-east, Nigeria. Two hundred and ninety-six (296) cassava accessions were sourced from the two regions through germplasm field survey and were assessed on the phenotyping experimental field of Central and West African Virus Epidemiology-Abdullahi Fodio University of Science and Technology, Aliero (WAVE-AFUSTA). The experiment was laid out using Augmented Randomized Block Design (ARBD). Descriptive statistics and multivariate analysis of the 296 x 14 qualitative data were conducted. Cassava accessions assessed showed low to high variation in relation to the qualitative traits. Accessions were grouped into four clusters (I, II, III and IV) based on qualitative traits. The distribution of the 296 accessions showed that nine (9) accessions were in cluster one (1), one (1) in cluster two (2), six (6) in cluster three (3) and 280 in cluster four (4). The grouping of 280 accessions in a cluster indicate that, the accessions are likely duplicates but with different names in different localities. The Factor Analysis of Mixed Data (FAMD) revealed that the variation observed among the studied accessions is driven predominantly by plant architectural and leaf morphological traits. The observed soma-clonal variation in this research highlights the potential of these accessions as valuable genetic resources for cassava improvement programmes. This study provides a foundation for molecular characterization that will screen the duplicates and reduce the germplasm size in Nigeria. This will ensure that accessions with high diversity are retained.

Keywords: Accessions, Soma-clonal variation, Qualitative traits, Northern Nigeria.

ABSTRACT: Morphological evaluation of tomatoes accessions is important for breeding and improvement programme on the crop. The lack of understanding on the genetic variation on tomato accession has led to little progress in breeding and improvement of the crop. The experiment was conducted at College of Agriculture, Science and Technology Lafia, Nasarawa State. Five tomato cultivars (Mona F1, Topaze, Boomerang F1, Riogrande + and Cirea) were used for the study in a randomized complete block design (RCBD) with three replications. Data were collected on traits such as plant height, number of branches, number of leaves, leaf area, stem girth, number of fruits, fruit weight, days to maturity, fruit girth and shelf life. All the data collected were subjected to Analysis of Variance (ANOVA). Mean separation was carried-out using LSD at probability 5% (p<0.05). The mean performance analysis revealed a significant genotypic difference across all traits. The coefficient of variation (CV) of 11.10% indicated moderate experimental precision. For plant height, Mona F1 (105.2 cm), Riogrande+ (115.3 cm), Boomerang F1 (116.7 cm), and Cirea (114.0 cm) formed a statistically similar tall group, while Topaze (88.0 cm) was significantly shorter. Boomerang F1 produced significantly more leaves (80.9) than all other genotypes, whereas Cirea produced the fewest leaves (28.8). Mona F1 and Boomerang F1 exhibited the largest leaf areas (39.77 cm² and 37.6 cm², respectively). Riograde (+) has longer shelf life (17.67 days), while Cirea had the shortest SL (8.33 days). This showed that the 112% difference is important for post-harvest management. The strongest negative correlation occurred between days to maturity and fruit girth (r = -0.868), indicating that late-maturing plants produce significantly smaller fruits. Days to maturity also showed strong negative correlations with fruit weight (r = -0.743) and shelf life (r = -0.694). Boomerang F1 showed superior fruit weight and fruit girth, Mona F1 performed well in fruit number, early maturity, and leaf area, while Riogrande + was outstanding for shelf life and high fruit count, which are useful for breeding and improvement of the crop.

Keywords: Accessions, Characterization, Heritability, Phenotypic diversity, post-harvest.

ABSTRACT: Genetic variation is essential for designing crop breeding programmes that achieve desired breeding objectives. This study evaluated variations in pod, seed, and leaf characteristics among F? hybrids derived from five purebred cowpea (Vigna unguiculata (L.) Walp.) lines. The experiment was conducted at the Federal University of Agriculture, Abeokuta (FUNAAB) using a completely randomized design with five replicates, giving a total of 25 experimental units. Both qualitative and quantitative traits were assessed. Qualitative traits were classified into phenotypic categories, while quantitative data were analyzed using analysis of variance (ANOVA) at ? = 0.05. No maternal or cytoplasmic effects were detected in the inheritance of seed coat texture, petiole formation, peduncle type, pod shattering, or the inverted V-shaped leaf mark. However, maternal effects significantly influenced quantitative traits, including seed weight, number of seeds per pod, ovules per pod, pod length, and leaf size, with seed weight showing the strongest maternal influence. No significant differences were observed between parental lines and F? progenies for ovules per pod, pod length, 100-seed weight, seeds per pod, and leaf size. Smooth seed coat, dehiscent pods, non-branching peduncles, and petiolate leaves exhibited dominance over their respective alternative traits. The findings highlight the importance of considering maternal effects when developing cowpea breeding strategies for improved quantitative traits.

Keywords: Reciprocal crosses, Maternal effect, Branching peduncle, Cowpea lines, Pod length.

ABSTRACT: Thirty-nine accessions of Cynodon dactylon collected from southwestern Nigeria were characterized using morphological traits and Random Amplified Polymorphic DNA (RAPD) markers to assess genetic diversity and identify germplasm with potential for breeding and conservation. Morphological evaluation was conducted at Akure and Ado-Ekiti using 23 traits. Principal component analysis showed that the first five components explained 71.90% and 66.36% of the total phenotypic variation, respectively, with leaf ratio, leaf width, stolon length, plant height, raceme length, and number of racemes contributing most to accession differentiation. Cluster analysis grouped the accessions into five clusters in Akure and three in Ado-Ekiti, while mixed-model analysis identified substantial variation in flowering and vegetative traits, with accession A2 (IRUN) showing superior performance for several agronomically important characteristics. RAPD analysis generated 53 loci, of which 43 were polymorphic (81.13%), and resolved the accessions into four genetic clusters. Analysis of molecular variance indicated that 63% of the genetic variation occurred within populations and 37% among populations. Accession A18 (IBOKUN) was genetically distinct, highlighting its conservation value. The combined morphological and molecular analyses revealed substantial diversity, providing valuable germplasm for conservation, parent selection, and the development of improved forage and turf cultivars.

Keywords: Cynodon dactylon, Genetic diversity, Germplasm characterization, Morphological diversity, RAPD markers.

ABSTRACT: Six maize lines × tester hybrids generated from three provitamin A-carrier maize inbred lines and two testers were evaluated across two contrasting agroecologies in Nigeria (Makurdi and Zaria) to determine combining ability and genetic variation for yield and other agronomic traits. The three inbred lines (AWSYN-Y2, BRLNTP-YC6, PVASYN13) and two testers (BR50-414, BR50-419) were crossed in a 3 × 2 design to generate six hybrids, which were evaluated alongside three commercial checks. Combined analysis of variance showed significant (p < 0.05–0.01) differences among genotypes for most agronomic traits including flowering time, leaf traits, cob weight, and 100-seed weight, while grain yield (t ha?¹) was not significant at the overall genotype level. Despite this, clear numerical differences were observed, with BRLNTP-YC6 × BR50-419 (6.52 t ha?¹) and AWSYN-Y2 × BR50-419 (6.38 t ha?¹) outperforming the best check (OBA SUPER 6, 5.51 t ha?¹). Combining ability analysis showed that BRLNTP-YC6 exhibited strong positive GCA effects, indicating a high frequency of favorable additive alleles for yield-related traits while AWSYN-Y2 contributed to earliness and plant architecture. Among testers, BR50-419 favored grain filling and kernel traits, whereas BR50-414 contributed to ear structural traits. Additive gene action predominated for several traits including leaf dimensions and grain yield, while non-additive effects were important for reproductive traits. Broad-sense heritability ranged from moderate to high for most traits, including grain yield (H² = 65.82%). Correlation analysis identified cob weight, stover yield, and 100-seed weight as the strongest contributors to grain yield. The results revealed BRLNTP-YC6 × BR50-419 and AWSYN-Y2 × BR50-414 as promising hybrids, while BRLNTP-YC6 and AWSYN-Y2 emerged as valuable parental lines for developing early and high-yielding provitamin A maize adapted to Nigerian agroecologies.

Keywords: Agroecology, Biofortification, Carotenoids, Heterosis, Heritability.

ABSTRACT: The field trial was conducted across two locations to examine the correlations among three cowpea varieties (IT-04K-321-2 1460, Ex Borno, and Ife Brown) as well as several key morphological traits, including days to 50% flowering, leaf area, branching, nodulation, and grain yield. The primary objective of this study was to offer valuable guidance for selecting the most appropriate variety for intercropping systems in the wet savanna zone of Nigeria. Employing the Pearson correlation coefficient (r) at a p-value of 0.0000, the relationships between the traits were assessed. A notable correlation of 0.7430 was observed between days to 50% flowering and branching, indicating a moderately strong and highly significant positive linear relationship. Conversely, the correlation coefficient of -0.1397 between grain yield and branching suggests a very weak and statistically insignificant relationship, implying that branching may not play a significant role in enhancing yield. Encouragingly, we found a robust Pearson correlation coefficient (r) of 0.6700 between nodulation and flowering, signifying a strong and statistically significant positive linear relationship. Additionally, the correlation coefficient (r) of 0.5385 indicates a fairly strong positive association between variety and grain yield in cowpea. These findings suggest that grain yield is a complex, heritable trait significantly influenced by positive interactions among vegetative growth traits (including leaf area and branching), physiological traits (such as nodulation), and reproductive development traits (like flowering). To optimize yields, we recommend the implementation of agronomic practices that promote the effective expression of these traits. This approach will aid in selecting cowpea varieties that are well-suited for new farming systems and ecological contexts, ultimately contributing to enhanced productivity and sustainability in agricultural practices.

Keywords: Agronomic traits, adaptability, cowpea variety, farming system. Correlation.

ABSTRACT: Marker-assisted backcrossing (MABC) strategy was used to introgress brown planthopper (BPH) resistant genes/quantitative trait loci (QTLs) from Rathu Heenati rice variety into the genome of Putra-2. A bi-parental mating design was used to develop F1 plants and subsequent backcross generations. The primary objective of this research was to develop high yielding and BPH resistant rice variety for cultivation in Malaysia, and also to determine the percentage recurrent parent genome (RPG) recovery of Putra-2 rice variety in BC1F1, BC2F1 and BC2F2 generations. Foreground and background selections were conducted at each generation of backcrossing in order to select progenies having desired genes/QTLs and maximum percentage RPG recovery. In respect of this, out of 316 simple sequence repeats (SSRs) markers screened for polymorphism between the two parents, 79 were found polymorphic, and these markers were used to screen the plants in BC1F1, BC2F1 and BC2F2 generations. The RPG recovery analysis ranged from 80.3 to 84.9% with a mean of 82.1% and from 93.0 to 95.2% with an average of 94.1%, in BC1F1 and BC2F1 generations, respectively. In the BC2F2 selected improved lines, the RPG analysis ranged from 96.4 to 97.2% with an average of 96.4%. Unlike conventional backcrossing, the utilisation of MABC accelerated RPG recovery and reduced the number of backcross generations required to incorporate BPH resistance genes/QTLs into genetic background of Putra-2 rice variety. Thus, marker-assisted selection (MAS) saves energy and time, cost effective, more efficient and reliable in the selection processes compared to traditional breeding methods.

Keywords: RPG recovery, Rice, MABC, BPH resistance genes/QTLs, foreground selection, background selection

ABSTRACT: A field experiment was conducted at the Teaching and Research Farm of the Michael Okpara University of Agriculture, Umudike, during 2024 and 2025 cropping to evaluate some hot pepper varieties. The treatments were laid in a randomized complete block design (RCBD) with three replications. The plot size was 2.0m x 3.0 m (6m2). Sowing of seed at nursery took place in March while the seedlings were transplanted into the field at two months after sowing. The data collected were subjected to analysis of variance (ANOVA). The treatment means were separated using least significant difference at 5% probability level and Pearson Correlation coefficient were used to compare association of characters. The results from the analysis of variance revealed that the number of branches, plant height, number of days to first flowering, number of days to 50% flowering, number of flowers per plant and fruit yield characteristics of pepper varieties were significantly (P ? 0.05) affected by variety. The variety Shombor produced highest plant height (101.20 cm). The earliest to flower was Star pepper that flowered at 51.3 days after transplanting (DAT), followed by Shombor that flowered after 56.0 DAT. The variety with the longest fruit was Shombor (8.1cm), followed by Atarodo (7.1cm). Shombor also produced the highest number of fruits per plant (219.6), while the least number of fruits per plant was obtained from Effia (9.8). Shombor produced the highest fruit yield per hectare (8407.0 kg/ha). This was followed by Star pepper that had fruit yield per hectare of 5624.4kg/ha. Atarodo and Effia had the least fruit yield per hectare with the values of 558.1 and 944.4 kg/ha, respectively. Result from correlogram showed that highly significant and positive correlation was observed between fruit yield per hectare and number of branches (r = 0.76**), number of leaves (r = 0.82***), weight per fruit (r = 0.74**) and fruit length (r = 0.73**) and significant negative correlation with number of days to 50% flowering (r = -0.71**), number of days to fruiting (r = -0.73**) and days to 50 % ripening (r = -0.62*). A highly significant and positive correlation was observed between plant height and fruit yield per hectare (r = 0.85***), number of branches (r = 0.86***), number of leaves (r = 0.87***) and weight per fruit (r = 0.72**).

Keywords: hot pepper, pepper varieties, yield, Correlogram, growth

ABSTRACT: Climate change is altering the ecosystems, affecting crop production, posing challenges on food security. Hence, the need to identify suitable environment for crop adaptation and production. Twenty-four soybean genotypes sourced from International Institute of Tropical Agriculture (IITA), Ibadan were planted using randomized complete block design (RCBD) with three replicates at three locations (Abeokuta, Lagos and Ibadan) to determine the responses of seed yield parameters across the environments. Data collected on number of days to 50% flowering, plant height at flowering, number of pods per plant, number of seeds per plant, 100 seed weight and yield per plant were subjected to analysis of variance (ANOVA), significant means were separated using Duncan Multiple Range Test (DMRT) at 5% probability level. Principal component analysis and genotypic correlation were done. The result showed that the three environments differed with respect to agrometeorological data collected, hence, affected the response of soybean yield traits evaluated. In terms of yield, Lagos and Ibadan are the ideal environments for soybean production. TGx 2004-10F remains a stable genotype with high yield, thus recommended for soybean improvement programme. Also, number of pods and seeds per plant contributed to yield observed. However, yield being a complex trait; further studies should be conducted to determine other characters contributing to soybean yield improvement.

Keywords: climate change, environment, seed yield, soybean, Genotype × Environment (G × E) interaction

ABSTRACT: Current world challenges in Bambara groundnut cultivation remained investigative with climatic change, limiting the agronomic and yield potentials. There is need to determine the optimal seed rate per hill for Bambara groundnut improvement. This becomes imperative to ensure efficient utilization of genetic resources, as request for seeds from genebanks come with limited seeds. Ten accessions were sourced from IITA, Ibadan. The experiment was laid out in a 10 × 2 factorial arranged in Randomized Complete Block Design (RCBD), replicated 3 times. Two (2) seeds and One (1) seed were planted per hill in a raised bed. The data was subjected to GLM procedure in Statistical Analysis Software (SAS), and significant difference was determined using Tukey HSD at P<0.05 and 0.01. Number of pods per plant and pod length were significantly different for one seed per hill. These two traits were significantly higher for one seed per hill indicating an efficient genetic resources utilization, and the need for further investigation. Principal Components 1–5 constituted 71.10% of the total relatedness. This study showed that nine traits are key traits to relatedness and diversity, and should be considered in the selection of parents in future research.

Keywords: Accessions, Climate change, Morphology, Seed rate, and Variation.