Abstract Moringa ( Moringa oleifera Lam.) is cultivated globally for leaf powder, fruit, seed oil and pharmaceuticals, yet germplasm characterization remains limited, constraining its use and improvement. We characterized 148 individuals from 32 families across seven countries/programmes in a two-season randomized complete block trial in Hawaii, USA, measuring 12 morphological, phenological and agronomic traits. Significant family-level variation (p < 0.05) was detected for nine traits. Genetic correlations between 1-year and 6-month post-coppice regrowth ranged from rg = 0.544 (leaf count) to rg = 0.776 (tree height), indicating trait-dependent rank stability; coppice shoot production was highly consistent between 1- and 6-month regrowth (rg = 0.896). Trait antagonisms between market classes were evident, with tree height positively correlated with leaf production ( r = 0.61) and flowering time negatively correlated with seed weight ( r = −0.41). Selection indices identified 80 individuals specialized for either leaf or fruit/seed markets, with none excelling in both, documenting complete market specialization not previously reported in moringa. These stable traits underpin principal markets, making this characterized, public-domain germplasm immediately valuable for market-targeted evaluation and breeding.
Abstract In the early 20th century, agricultural production was mostly focused on traditional, low-input systems where seed was actively selected by farmers and then frequently saved on-farm for sowing in subsequent seasons. More recently, the replacement of diverse landraces (LR) with fewer genetically homogeneous, commercially bred cultivars has led to considerable genetic erosion and loss of valuable plant genetic resources. Without appropriate in situ and ex situ conservation, it is inevitable that genetic erosion will continue at an undesirable rate until the loss of these unique resources. Earlier projects to document and inventory LR cultivation in the United Kingdom (UK) provide some insights but were incomplete, leaving research gaps that still need to be addressed. This research provides information on the current status of UK wheat LR diversity and identifies the significant challenges associated with cultivating LR on-farm. A total of 50 farmer interviews were conducted between January and June 2024. It was found that the number of wheat LR maintained on-farm, and the scale at which these varieties are grown, has increased since 2009. There are now 27 varieties maintained over 700 hectares. However, lack of market demand and seed availability have been shown to limit the conservation of these varieties, and therefore, strategies should be implemented to overcome some of the challenges associated with the cultivation of LR. Recommendations are put forward to encourage their continued growing on-farm, and to safeguard important plant genetic resources for future generations.
Abstract This review synthesizes six decades of research on native Himalayan rice (NHR) (Oryza sativa) – encompassing cold-tolerant high-altitude landraces, drought-tolerant upland rice, Basmati, aromatic and glutinous varieties. The aims of the review were to assess NHR diversity and richness, analyze genetic erosion, evaluate their roles in farming systems and value chains, identify research gaps and explore opportunities for improvement and commercialization. We discuss genetic erosion, their adaptive traits and commercial potential. Drawing on three major national assessments (1970s, 1990s and 2015), a comparative analysis revealed an alarming rate of genetic erosion: in 2015, only 10% of those recorded in the 1990s were found, and only 6% of the landraces were reported in the 1970s. Over 93% of existing NHR landraces are classified as endangered or critically endangered, with relatively lower erosion among Basmati (73%) and speciality types (81%). Molecular studies indicated high genetic diversity determined by altitude, farming systems and culinary traditions. A few coarse-grained aerobic upland rice landraces were found to have aroma. Nepal’s speciality rice, cultivated under chemical-free management in ecologically pristine environments irrigated by Himalayan rivers and snow melt, possesses significant potential for domestic and export markets. However, inadequate nutritional profiling, absence of geographical indication frameworks, fragmented seed systems and weak value chains constrain commercialization. The review identifies priority areas for research, including targeted genomic mapping, rigorous nutritional profiling, true-to-type seed systems and strengthened value chains, all of which can contribute to conserving this important genetic resource through utilizing diversity in breeding and commercialization.
Abstract Traditional conservation monitoring often relies on morphological abundance, which can mask critical underlying genetic erosion. This study investigates the ‘Abundance Paradox’ in Southwest Nigeria through a combined morpho-molecular assessment of the Piper and Pterocarpus genera – taxa of significant ethno-medicinal and timber value. We employed a robust integrated approach combining 31 vegetative descriptors with chloroplast Simple Sequence Repeat ( SSR) , nuclear SSR and Amplified Fragment Length Polymorphism ( AFLP) markers to assess genetic diversity across a Lowland Rainforest-Derived Savanna gradient. Sampling covered five distinct land-use types: Primary forest reserves, degraded secondary forests, smallholder farmlands, institutional gardens and sacred groves. Analysis revealed that while Piper guineense appears locally abundant in farmlands, it suffers a significant 12% reduction in expected heterozygosity ( He ) and shows clear signs of a recent bottleneck ( P < 0.05). In contrast, Pterocarpus erinaceus demonstrated high genetic differentiation ( F ST = 0.24), leading to the identification of three distinct evolutionarily significant units aligned with regional ecological zones. Sacred groves were found to maintain biodiversity levels comparable to primary forests, outperforming degraded areas. These data demonstrate that high phenotypic frequency is a misleading proxy for genetic health, and that morphological plasticity in disturbed habitats masks underlying genomic erosion. We provide actionable recommendations for the National Biodiversity Strategy and Action Plan 2025–2030, emphasizing the need for molecular auditing to safeguard the adaptive potential of underutilized tropical genetic resources.
