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

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

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

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

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