Sesame is an orphan crop with little research attention in Kenya. Genetic relationship between cultivated sesame and related wild species in Kenya is not well known. The objective of this study was to determine genetic relationship between traditional landraces of sesame and related wild species using somatic chromosome counts and isozyme markers. Somatic chromosome counts of four wild species revealed a consistent chromosome number of 2n = 32, which differed from that of the cultivated sesame (2n = 26), indicating genetic variation in chromosome counts. Only esterase exhibited significant variation and accession-specific esterase bands were identified. Three cathodic and eight anodic bands were observed and the variable bands ranged from 2 to 6 per accession. Cathodic bands with varied relative migration were observed in wild species only, whereas anodic bands were observed for all the accessions. Accessions of cultivated sesame were more genetically diverse compared to wild species. Morogoro, 107UG, Indian-1 and Indian-2 recorded the highest number of esterase bands, while 103w had the lowest number of bands. Few common bands were found between cultivated sesame and related wild species indicating a distant genetic relationship. Few gene markers are available in sesame and related wild species, therefore, esterase isozymes can contribute to studies in the breeding and genetics of sesame. Key words: Genetic variation, isozyme, chromosome counts, wild species, sesame.

Community Seed Banks (CBs) can be central to seed sovereignty, agrobiodiversity conservation, and enhance farmer resilience to climate change. However, analysis of their sustainability strategies and challenges remains underexplored in Kenya, particularly at the community level. This study analyzed sustainability strategies and challenges influencing the long-term viability of 18 CSBs across selected study sites in Kenya. A participatory, field-based mixed-methods approach combining focus group discussions, key informant interviews, field observations, and desk review were applied. Results show that the sampled CSBs are governed through volunteer-driven, and culturally embedded committees, with membership rising from 901 to 2, 231 between 2018 and 2024, over 80% of whom were women. Across the studied CSBs, a wide range of neglected and underutilized crops were conserved, often reintroduced into local farming systems. More than 80% of the CSBs examined reported transitioning into agroenterprises, producing a variety of products such as composite flours, cooking oils, crisps, bio-inputs, and nutraceutical powders, thereby linking conservation to household nutrition and income generation. Solidarity groups engaged in table banking and ecological practices such as compositing, agroforestry, and biofertilizers and biopesticides, also contribute to local adaptive capacity within the study contexts. Despite these innovations, sustainability among the sampled CSBs was constrained by structural barriers, including product certification costs, unfavourable seed laws, leadership conflicts, and under-characterization of conserved crops. CSBs sustainability can be enhanced through participatory crop characterization, affordable quality assurance mechanisms, and integration into national and sub-national agricultural policies. Future research should assess long-term economic outcomes, gendered participation dynamics, and the resilience of CSBs under climate and market shocks.

Low phosphorus (P) in agricultural ecosystems limits growth of bambara. Field trials were carried out at 2 P levels (0 and 35 kg/ha) to determine the variation of 12 bambara genotypes in phosphorus efficiency, identify P-efficient and responsive genotypes for cultivation in sub-optimal P environments. Genotypes differed significantly (P ≤ .05) in plant biomass, grain and biological yields due to P levels and seasonal effects. BAM002, BAM010 and BAM011 recorded high grain yields in both seasons. Phosphorus accumulation (PA) in biomass, grain and biological yields was influenced by genotype, P levels and genotype * P levels interaction. High yielding P-efficient and responsive genotypes including BAM002, BAM010 and BAM011 also had high values of phosphorus physiological efficiency index and phosphorus harvest index at low P indicating that they are P-efficient. Genotypes were classified into four and three groups based on the relationship between total PA and grain yield at low and adequate P, respectively. Moreover, genotypes were categorised into in-efficient, medium and efficient based on total index score. Principal component analysis grouped together the genotypes BAM002, BAM010 and BAM011 at both P levels. These genotypes are adapted to P-deficient soils and utilise acquired P efficiently for optimum grain production.

Phosphorus (P) deficiency is a major constraint to crop production. Phosphate-solubilizing bacteria (PSB) offers a sustainable alternative to synthetic fertilizer application. However, the identity, efficiency, and growth-promoting potential of PSB in the rhizosphere of wild sorghum (Sorghum halepense L. Pers) remain poorly understood. This study aimed to determine the genetic diversity of rhizobacteria associated with wild sorghum, assess their ability to solubilize various insoluble phosphate sources and evaluate the potential of broad-spectrum PSB to enhance the growth of cultivated sorghum (Sorghum bicolor L. Moench) under Mijingu rock phosphate (MRP) fertilization. Rhizobacteria were characterized based on morphological, biochemical, and genetic traits. The ability to solubilize calcium phosphate, aluminum phosphate, inositol phosphate, and MRP was tested using the National Botanical Research Institute Phosphate medium. A greenhouse study was conducted to evaluate the growth-promoting potential of broad-spectrum PSB, including Citrobacter sp. SB02-1 and SB04-3, Serratia sp. SB03-1, and Raoultella sp. SB07-2, in MRP-fertilized sand. Sixteen bacterial isolates were identified, representing species such as Proteus sp., Pseudomonas sp., Raoultella sp., Citrobacter sp., Morganella sp., Serratia sp., Enterobacter sp., and Klebsiella sp. These isolates exhibited diverse abilities to solubilize insoluble phosphate sources, with Citrobacter sp. SB02-1 and Citrobacter sp. SB04-3 releasing the highest quantities of P (> 100 mg/l). Inoculation with Citrobacter sp. SB04-3 significantly improved sorghum growth, resulting in increases in the number of leaves (66.7%), shoot length (61.3%), root length (89.3%), root biomass (212.5%), and dry weight (280%) compared to non-inoculated plants. Remarkably, the performance of Citrobacter sp. SB04-3 was comparable to plants treated with balanced soluble fertilizers without inoculation. This study is among the first to demonstrate that Citrobacter sp. SB04-3, isolated from wild sorghum rhizosphere, can match the performance of synthetic fertilizers by significantly enhancing sorghum growth and biomass under MRP fertilization. This novel finding highlights its potential as a cost-effective and sustainable alternative for P management in agriculture.