Investigation of Cowpea (Vigna unguiculata (L.) Walp.)–Insect Pollinator Interactions Aiming to Increase Cowpea Yield and Define New Breeding Tools

Impact of pollination on the agri-food sector is of paramount importance. Pollinators contribute to the maintenance of ecosystems, the reproduction and survival of many plants, and their presence usually leads to increased yield and quality of agricultural products. Breeding and selecting for plant traits for enhancing pollinator visits could therefore lead to more resilient farming systems. In stating the advantages of enhancing pollinators in agricultural systems, this study was designed aiming to assess six cowpea accessions for their flower traits and their effect on insect-pollinators. Pollinators species abundance and foraging activity was recorded and their impact on yield was investigated. Twenty-five of the twenty-seven flower traits studied differed statistically significantly among cowpea accessions. The main pollinators recorded belonged to the genus Xylocopa (Latreille, 1802). Seed and fresh pod yield was not affected by pollinators. The floral traits related to pollinators abundance and foraging activity were flower color, inflorescence position and the hours that the flowers per plant remained open during the day. However, they were not related linearly to pollinators abundance and foraging activity; therefore, they did not constitute safe traits for selection aiming to increase pollinators visitation. The findings suggested that other traits, such as pollen and nectar reward, probably perform a more important role in attracting pollinators compared to flower traits

Enhancing legume ecosystem services through an understanding of plant–pollinator interplay

Legumes are bee-pollinated, but to a different extent. The importance of the plant– pollinator interplay (PPI), in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: (1) optimal productivity, based on an efficient use of pollinators, and (2) biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the “pest control service” and pollinators in legume crops. The final section addresses general approaches to encourage the synergybetweenfoodproductionandpollinationservicesatfarmerfieldlevel.Twobasic approaches are proposed: (a) Farming with Alternative Pollinators and (b) Crop Design System

State of Crop Landraces in Arcadia (Greece) and In-Situ Conservation Potential

Genetic erosion of landraces is increasing worldwide, however there are still regions rich in landrace biodiversity, such as islands and mountainous isolated areas. Defining the reasons of landrace abandonment in these areas, as well as collecting and preserving landraces, is of outmost importance. In this context, the Agricultural University of Athens organized missions in 53 villages of Arcadia, a prefecture rich in floral biodiversity and variable climatic conditions and topography. The aim was to collect samples of the on-farm (in-situ) conserved annual crop landraces and record the location of perennial crop local varieties. Since traditional knowledge and practices have been playing a vital role in the survival of landraces and local varieties, information was obtained through personal interviews with locals using semi-structured questionnaires. Even though the number of accessions collected from Arcadia has been reduced (141 samples) compared to previous collections and genetic erosion is advancing dramatically for cereals and pulses, a significant number of landraces is still cultivated by the locals. The reasons of landrace abandonment were other sources of occupation than agriculture, such as public service jobs, mechanization, and commercialization of agriculture. Gastronomic and agro-tourism along with European Union trademarks and policies can support locals in landrace/local varieties in-situ conservation

Vegetable Grafting; Principles and Practices

Although grafting has been practised on fruit trees for thousands of years, thecommercial application of grafting on vegetables constitutes a relatively recentinnovation in most countries. After more than 50 years of vegetable crop improvement,dedicated principally to selecting for above-ground traits, scientistsnow perceive root system engineering as an opportunity for integrating dynamicnovel approaches in fostering sustainable vegetable production under changingenvironmental conditions, while minimizing the demand for new resources.Introduction of excellent rootstocks possessing multiple resistances and efficientgrafting systems will greatly encourage the extended application of vegetablegrafting all over the world. Although the benefits of using grafted transplantsare now fully recognized worldwide, the need to enlighten the scientific basis ofrootstock–scion interactions under variable environmental pressures remainsvital for extracting grafting-mediated crop improvement. This has promptedthe COST Action FA1204 entitled ‘Vegetable grafting to improve yield and fruitquality under biotic and abiotic stress conditions’ aimed at systematizing researchfindings (http://www.vegetablegrafting.unitus.it). The COST action allowed thedevelopment of a multidisciplinary network of partners targeting the root systemand employing rootstock breeding to unravel the mechanisms behind rootstock-mediatedcrop improvement: the enhancement of productivity and fruit quality,and the sustainability of vegetable crops under multiple and combined stresses.The current book is the major output of the COST Action and contains ninechapters drawing on the 2012–2016 activities of four Working Groups (WGs)dealing with ‘Genetic resources and rootstock breeding’ (WG1), ‘Rootstock–scioninteractions and graft compatibility’ (WG2), ‘Rootstock-mediated resistance tobiotic and abiotic stresses’ (WG3) and ‘Rootstock-mediated improvement of fruitquality’ (WG4). While recent advances of scientific knowledge constitute thecore of this COST book, valuable practical information is also provided on rootstock–scion combinations, on applicable grafting methods, on the establishment of grafted transplants and on recommendations for the use of grafted plants as aneffective tool for sustainable vegetable production.This book could not have been produced without the dedication and help ofmany, and we would like to thank the authors and co-authors who contributed tothe compiled chapters. However, we would also like to express our appreciation toa large number of scientists and experts who served as reviewers and contributedto improving the quality of the book. Finally, we would like to thank the COSTAssociation in Brussels (Belgium) for funding COST Action FA1204 and providingadditional financial support for publishing the current book.We planned and compiled this book as a collection of scientific informationand as a practical tool aimed at both the people involved in the commercial productionand cultivation of grafted plants, as well as researchers interested in anunderstanding of the science and technology behind a grafted plant. We hope allreaders benefit from this book and we remain open to ideas and proposals on howto amend a future edition.</p

Crop Wild Relatives: A Valuable Source of Tolerance to Various Abiotic Stresses

Global climate change is one of the major constraints limiting plant growth, production, and sustainability worldwide. Moreover, breeding efforts in the past years have focused on improving certain favorable crop traits, leading to genetic bottlenecks. The use of crop wild relatives (CWRs) to expand genetic diversity and improve crop adaptability seems to be a promising and sustainable approach for crop improvement in the context of the ongoing climate challenges. In this review, we present the progress that has been achieved towards CWRs exploitation for enhanced resilience against major abiotic stressors (e.g., water deficiency, increased salinity, and extreme temperatures) in crops of high nutritional and economic value, such as tomato, legumes, and several woody perennial crops. The advances in -omics technologies have facilitated the elucidation of the molecular mechanisms that may underlie abiotic stress tolerance. Comparative analyses of whole genome sequencing (WGS) and transcriptomic profiling (RNA-seq) data between crops and their wild relative counterparts have unraveled important information with respect to the molecular basis of tolerance to abiotic stressors. These studies have uncovered genomic regions, specific stress-responsive genes, gene networks, and biochemical pathways associated with resilience to adverse conditions, such as heat, cold, drought, and salinity, and provide useful tools for the development of molecular markers to be used in breeding programs. CWRs constitute a highly valuable resource of genetic diversity, and by exploiting the full potential of this extended allele pool, new traits conferring abiotic-stress tolerance may be introgressed into cultivated varieties leading to superior and resilient genotypes. Future breeding programs may greatly benefit from CWRs utilization for overcoming crop production challenges arising from extreme environmental conditions

The Relation between Flower Traits of Bitter Vetch Landraces and Potential Insect Pollinators’ Visitation

Plant–pollinator interactions research can assist in the development of more ecologically friendly crop breeding methods, leading to enhanced global food security. In the present study, we have aimed to assess fifteen floral traits as insect attractancies of six bitter vetch (Vicia ervilia (L.) Willd.) landraces, a neglected crop. Four traits related to seed yield were also measured. Abundance and foraging behavior of potential insect pollinators on bitter vetch flowers were recorded, and their species were identified. Differences among landraces regarding floral and yield traits were statistically significant in most cases. A total number of four insect species were recorded as positively visiting flowers and constituting potential pollinators of bitter vetch. At a landrace level, there was a positive correlation between potential insect pollinators’ foraging activity and the number of open flowers, especially for the landrace ERV65-Kastania, Korinthia (p ≤ 0.01). Floral tube length, as well as standard petal length, was also positively correlated in some cases with potential insect pollinator species abundance and their visitation frequency. A positive correlation was also recorded between seed yield-related traits, which varied among landraces, and potential insect pollinators’ foraging activity. The results showed that bitter vetch flowers can attract and receive positive visits from insects, despite their mainly self-pollination reproductive system. Bitter vetch flower traits, such as the number of open flowers, floral tube length, and standard petal length, could, therefore, be useful as breeding tools, aiming to develop varieties with insect pollinator-friendly traits that could lead to enhanced seed yield production and help to conserve wild insect species biodiversity in the context of sustainable agriculture