Maximizing the crop wild relative resources available to plant breeders for crop improvement

Crop breeders are currently facing the need to continue increasing crop production to feed the growing human population, while mitigating the negative impacts of climate change on agriculture. Taxonomic and genetic diversity, which includes taxa, genes and alleles that offer novel sources of resistance to pests, disease and abiotic factors that affect crop quality and quantity, are a key tool for crop breeders to address these challenges. Lack of access to this diversity is currently limiting crop improvement. This paper focuses on how the breeder's requirement for greater diversity may be met despite the continue challenges of growing human population, and the impacts of climate change. It is argued that gene pool diversity is largely concentrated in crop wild relatives (CWR) and their more active conservation, especially focusing on in situ conservation applications, will enable the breeding challenges to be met. Further, that the science of in situ conservation is only now coming of age but is sufficiently advanced to facilitate the establishment of integrated national, regional, and global in situ CWR conservation networks. For humankind to substantially benefit from the additional adaptive diversity made available through these collaborative networks for CWR in situ conservation for the first time, breeders need to be provided with the critical resources necessary to address the negative impacts of climate changes on food production—therefore promoting greater global food security

In situ and ex situ conservation gap analyses of crop wild relatives from Northeast Africa

Crop Wild Relatives (CWR) are wild plant taxa closely related to domesticated crops that play a vital role in enhancing crop resilience. This study assessed the conservation status of 97 priority CWR in Northeast Africa through a comprehensive approach, incorporating ecogeographic data and complementarity analysis. The analysis of 4551 occurrence records from 57 CWR highlighted significant gaps in in situ conservation. Notably, the highest number of occurrence records within Protected Areas (PAs) were found in Ethiopia, particularly in Borena National Park, Kafa UNESCO-MAB Biosphere Reserve, and Bonga National Forest Priority Area. However, only 40 taxa (~ 42%) were identified within existing PAs, with Solanum campylacanthum Hochst. cx A. Rich, and Coffea arabica L. being the most prevalent. Ecogeographic Land Characterization (ELC) maps identified 45 distinct ecological zones representing the region’s diverse habitats. Ex situ analysis revealed 1295 occurrence records from 52 taxa (54%) conserved in genebanks, although only 8% of these taxa were represented by more than 50 accessions. S. camplyacanthum and Avena vaviloviana (Malz.) Mordv. had the highest number of accessions. Ecogeographical analysis indicated that ELC zones 8, 17, and 18 had the highest frequencies of occurrence in both PAs and genebanks. Complementarity analysis identified 34 potential genetic reserve areas, covering 42 taxa (43%), compared to 33 taxa conserved across 18 PAs identified by coverage analysis. These findings highlight the urgent need for a comprehensive CWR conservation strategy to protect valuable genetic diversity for future crop breeding programs, ultimately enhancing crop resilience in the face of ongoing and future agricultural challenges

Towards a practical threat assessment methodology for crop landraces

Crop landraces (LR), the traditional varieties of crops that have been maintained for millennia by repeated cycles of planting, harvesting, and selection, are genetically diverse compared to more modern varieties and provide one of the key components for crop improvement due to the ease of trait transfer within the crop species. However, LR diversity is increasingly threatened with genetic erosion and extinction by replacement with improved cultivars, lack of incentives for farmers to maintain traditional agricultural systems, and rising threats from climate change. Their active conservation is necessary to maintain this critical resource. However, as there are hundreds of thousands of LR and millions of LR populations for crops globally, active conservation is complex and resource-intensive. To assist in implementation, it is useful to be able to prioritise LR for conservation action and an obvious means of prioritisation is based on relative threat assessment. There have been several attempts to propose LR threat assessment methods, but none thus far has been widely accepted or applied. The aim of this paper is to present a novel, practical, standardised, and objective methodology for LR threat assessment derived from the widely applied IUCN Red Listing for wild species, involving the collation of time series information for LR population range, LR population trend, market, and farmer characteristics and LR context information. The collated information is compared to a set of threat criteria and an appropriate threat category is assigned to the LR when a threshold level is reached. The proposed methodology can be applied at national, regional, or global levels and any crop group

In situ and ex situ conservation gap analyses of West African priority crop wild relatives

AbstractCrop wild relatives are genetically related wild taxa of crops with unique resources for crop improvement through the transfer of novel and profitable genes. The in situ and ex situ conservation gap analyses for priority crop wild relatives from West Africa were evaluated using species distribution modelling, ecogeographic diversity, and complementary analyses. A total of 20, 125 unique occurrence records were used for the conservation gap analysis, however, 26 taxa had no occurrence data. 64 taxa (62.7%) occurred in protected areas, 56 taxa (55%) were conserved ex situ, while 76.7% (43) of the accessions are underrepresented with less than 50 accessions conserved ex situ. Areas of highest potential diversity were found in the Woroba and Montangnes districts in Cote d’Ivoire, Nzerekore, Faranah, Kindia, and Boke regions of Guinea, South-South, and North-East zones of Nigeria, and Kono and Koinadugu districts in Sierra Leone. Hotspots were found in Atlantique, Littoral, Mono, Kouffo, Atakora, Donga, and Colline provinces of Benin, Accra, and Volta regions of Ghana, North–Central Nigeria, and Lacs district of Cote d’Ivoire and Nzerekore region of Guinea. 29 reserve sites for active in situ conservation were identified, 11 occur in protected areas, while 18 are located outside protected areas. The establishment of the reserve sites will complement existing PAs and ensure long-term active in situ and ex situ conservation and sustainable utilization of priority crop wild relative to underpin food security and mitigate climate change in the region.</jats:p

DNA barcoding of the genus Verbascum (Scrophulariaceae) in the Arabian Peninsula

Verbascum and Rhabdotosperma are members of the family Scrophulariaceae. The first genus comprises approximately 360 species from almost all parts of the world, while the second contains a total of 8 species from tropical Africa and the Arabian Peninsula. Since 1977, the relationships between Verbascum and Rhabdotosperma continue to be contested. The present study aims to present the phylogenetic relationships and status among Verbascum species in the Arabian Peninsula. For phylogenetic analyses, maximum parsimony and Bayesian inference were performed. In total, 236 DNA sequences from 59 specimens of Arabian Verbascum were analysed. The phylogenetic analysis of one nuclear (ITS) and three chloroplastic (rbcL, matK, trnL) markers confirmed the monophyly of Verbascum, including the genus Rhabdotosperma. In addition to presenting novel phylogenetic relationships among the different Verbascum species in the Arabian Peninsula, our study reduced the species count of Arabian Verbascum to 16. Moreover, the phylogenetic analysis strongly supports the reinstatement of the genus Rhabdotosperma into Verbascum based on the Bayesian and maximum parsimony analyses

Rhabdotosperma saudiarabicum (Scrophulariaceae), a new species from Saudi Arabia

A new species of (Scrophulariaceae) is described from southwestern Saudi Arabia. For 75 years, the species was confused with and . The new species is illustrated with information on identification, distribution, specimens examined, habitat, conservation status, phenology, etymology, and taxonomic notes