Breeding Innovations in Underutilized Temperate Fruit Trees

The recent growing interest in minor species (i.e., fig, pomegranate, feijoa, etc.) has recently driven new research on breeding and genetics to address producer and consumer traits. Since these species have received little attention from the scientific community, they were less improved via conventional breeding, and lacked detailed genomic information on important traits. This lack of data, together with a general poor genetic knowledge of these species, has limited a wider cultivation of varieties with improved characteristics. For these reasons, and with the objective to increase the interest of scientists, farmers, and consumers for these fruits, this Research Topic “Breeding Innovations in Underutilized Temperate Fruit Trees” comprises biochemical, morphological, and genetic studies on some minor species regarding fruit trait variation, resistance, evolution, or sex determination. In this context, Marcotuli et al. examined the mechanisms behind the bud evolution toward breba or main crop in fig (Ficus carica L.), since this aspect remains unclear. The X-ray images of buds showed a great structural similarity between breba and the main crop during the initial stages of development, but breba inflorescence differentiation was completed in two seasons whereas that of main crop started at the end of winter and was completed within 2–3 months in the same season. The higher expression of floral homeotic protein AGAMOUS in breba compared to the main crop may indicate a role of these fruits on staminate flowers’ production for pollination of the main crop, as profichi act in the caprifig. Within the same species (Ficus carica L.) and for sexual determination, Ikegami et al. analyzed the FcRAN1 gene (during a breeding program for the selection of female plants) strongly associated with the sex phenotype. A male-biased segregation ratio distortion was obtained in 12 F1 populations, suggesting some genetic factor(s) affecting it. A comparison between the annotated genes and the genes required for normal embryo or gametophyte development and function identified several candidate genes responsible for the segregation distortion in fig. Following the same topic, Wang et al. hypothesized an early sex-identification method to improve breeding efficiency. The use of a deletion as a forward primer, a newly established AG-Marker, was as accurate as the RAN1-Marker, and provided the identification of male plants, giving new clues to understanding Ficus sex determination. Moving toward another attracting species, i.e., pomegranate (Punica granatum L.), Trainin et al. investigated the black peel color of some pomegranate varieties. Biochemical analysis revealed that delphinidin is highly abundant in the peel of black varieties and the pattern of anthocyanin accumulation is different from that of other pomegranates with red or pink colors of the peel. Genetic analysis of an F2 population segregating for the black phenotype revealed that it is determined by a single recessive gene. Pomegranate was also studied by Goudappa Patil et al. with regards to the SSR of “Tunisia” pomegranate variety. There was a positive trend in chromosome length and the SSR abundance, as marker density, enhanced with a shorter chromosome length. Examination of the distribution of SSR motif types within a chromosome suggested the abundance of hexanucleotide repeats in each chromosome followed by dinucleotides. A comprehensive set of highly polymorphic genome-wide SSRs was successively developed and tested. These chromosome-specific SSRs could serve as a powerful genomic tool to leverage future genetic studies, germplasm management, and genomics-assisted breeding in pomegranate varieties. Some evolutionary aspects of pear were investigated by Kumar et al. who put a light on runs of homozygosity (ROH) in self-incompatible plants, in particular Asian pears, European pears, and interspecific hybrids using genotyping-by-sequencing. The observed ROH patterns suggested that systematic breeding of European pears would have started earlier than Asian pears. Fruit trait variation in Persian walnut (Juglans regia L.) was addressed by Bernard et al. who conducted a genome-wide association study (GWAS) using multi-locus models in a panel of 170 accessions of J. regia to elucidate the genetic determinants of fruit quality traits in walnut toward the breeding of new varieties. The authors proposed several candidate genes involved in nut characteristics, such as a gene coding for a beta-galactosidase linked to several size-related traits and known to also be involved in fruit development in other species. With regards of fruit traits, Kyratzis et al. investigated the germplasm of an ancient species, the carob (Ceratonia siliqua L.), on the island of Cyprus. The domestic germplasm varies both in terms of pod morphology and composition, reflecting the genetic and physiological characteristics of both grafted and non-grafted accessions, and possibly the impact of agro-environmental conditions. Morphological traits, such as seeds-to-pod weight ratio, pod width, and thickness, were principally under genetic control. Contrarily, chemical compounds, particularly total phenolic content, including condensed tannins, in vitro antioxidant capacity, and to a lesser extent gallic acid, organic acids, sugars (glucose and fructose), and minerals were more under agro-environmental control. In the Southern Hemisphere, Quezada et al. worked on feijoa (Acca sellowiana Berg.), a fruit tree species native to Uruguay and Brazil. A high-density composite genetic linkage map of feijoa was constructed using two genetically populations. Genotyping by sequencing (GBS) approach was successfully applied for developing single nucleotide polymorphism (SNP) markers. They used both the reference genome of the closely related species Eucalyptus grandis and a de novo pipeline to construct a composite map. A novel approach for the construction of composite maps where the meiosis information of individuals of two connected populations is captured in a single estimator is described. The topic of resistance was carried out by Alves et al. in order to find sources of genetic resistance to Huanglongbing (HLB)-associated “Candidatus Liberibacter asiaticus” (Las), one of the most destructive diseases of citrus. Some genotypes from subtribe Citrinae, sexually incompatible but graft-compatible with Citrus, may provide new rootstocks able to restrict bacterial titer in the canopy. Authors tested for Las resistance a wide collection of graft-compatible Citrinae species using an aggressive and consistent challenge-inoculation and evaluation procedure. Eremocitrus glauca and Papua/New Guinea Microcitrus species as well as their hybrids resulted in full resistance, opening the way for using these underutilized genotypes as Las resistance sources in breeding programs

Deficit irrigation and emerging fruit crops as a strategy to save water in Mediterranean semiarid agrosystems

Water scarcity in Mediterranean climate areas will be progressively aggravated by climate change, population increase and urban, tourism and industrial activities. To protect water resources and their integrity for future use and to improve biodiversity, besides following advanced deficit irrigation strategies in fruit cultivation, attention could well be directed towards what are at present underused plant materials able to withstand deficit irrigation with minimum impact on yield and fruit quality. To this end, the state of the art as regards deficit irrigation strategies and the response of some very interesting emerging fruit crops [jujube (Zizyphus jujuba Mill.), loquat (Eriobotrya japonica Lindl.), pistachio (Pistacia vera L.) and pomegranate (Punica granatum L.)] are reviewed. The strengths and weaknesses of deficit irrigation strategies and the mechanisms developed by these emerging fruit crops in the face of water stress are discussed. The response of these crops to deficit irrigation, with special attention paid to the effect on yield but also on fruit quality and health-related chemical compounds, was analysed in order to assess their suitability for saving water in Mediterranean semiarid agrosystems and to analyze their potential role as alternatives to currently cultivated fruit crops with higher water requirements. Finally, the factors involved in establishing an identity brand (hydroSOS) to protect fruits obtained under specific DI conditions are discussed

Medicinal plants from the Himalayan region as potential novel antimicrobial and anti-inflammatory skin treatments

Background and Objectives: Adequate treatment of wounds remains one of the major medical needs globally, most notably in the regions with poor or limited access to health care. In many local and traditional systems of medicine, plants are often widely used for treating infected wounds. / Aim and objectives: The overarching aim of this project was selection of potential species for use in a future treatment by combining with plant resources with aspects of antimicrobial photodynamic therapy (aPDT). Specifically, we focussed on species used locally in the Himalayan region for the treatment of skin disorders and then assessed the existing pharmacological evidence for key species based on the published evidence available. / Methods: Database searches were performed to identify relevant publications describing local and traditional uses of plants in the Himalayan region of Bhutan, PR China, India, Nepal and Pakistan. Using the Global Biodiversity Information Facility (GBIF), species were researched in terms of their distribution including in different climatic regions, focussing on species mostly found in higher climatic zones (based on the Köppen–Geiger climate classification). For species used in three or more countries and restricted to the higher altitudes, data on safety, pharmacology, as it relates to dermatological conditions, and phytochemistry were retrieved. / Key findings: The study identified a total of 606 species that are used in the treatment of various skin conditions often associated with infections reported in 84 articles. Common weeds like Ageratum conyzoides and Bidens pilosa, widely used and cultivated species like Centealla asiatiaca and Prunus armenica were excluded. This ultimately led to the identification of a core group of five widely used species restricted to the Himalayan region (Cedrus deodara, Nardostachys jatamansi, Pinus wallichiana, Pinus roxburghii and Valeriana jatamansi). / Conclusions: Here we apply a novel approach comprising an assessment of the published information on the use of medicinal plants (i.e. local and traditional knowledge) in the context of their potential to be used in a biomedical form of clinical treatment – aPDT. Then, once sustainable sourcing based on access and benefit-sharing arrangements is in place, these species are investigated for their potential in wound treatment. Ultimately, the goal is to develop a new baseline for primary health care in some of the regions of the world with poor or limited access to health care

Authenticity of Honey: Characterization, Bioactivities and Sensorial Properties

Honey is a very complex food that requires multiple analytical, statistical and mathematical methods to guarantee honey authentication. This Special Issue contains innovative research on different analytical procedures for the determination of chemical compounds, functional properties, sensory characteristics and pollen profiles for the interpretation of the botanical and geographical origin of honey. This book compiles twelve original studies that address these issues and improve the knowledge of honeys of multiple botanical and geographical origins

Site Suitability Assessment for Irrigating Urban Landscapes with Water of Elevated Salinity in the Southwest. Consolidated Final Report. Part 1. Water Quality and Plant Tolerance

With increasing population and the demand for potable water, water with elevated salinity and reclaimed water are now commonly used for irrigating urban landscape in many communities in the arid Southwest. It not only saves potable water, but also provides the stable supply of irrigation water for maintaining urban greenery and recreational facility, usually at a discounted price. There are many examples of successful use of water with elevated salinity, such as shown in Fig. 1-1. At the same time, there have been reported cases of landscape quality degradation in some of these use sites. The degradation includes foliar damage, stunted growth, premature defoliation, and in some cases, tree mortality. Thinning of turf covers is also reported, especially in sports fields irrigated with water of elevated salinity. In order to reduce the incidences of landscape quality degradation, Texas AgriLife Research Center at El Paso, in cooperation with both water providers and water users, has been investigating salt tolerance of various landscape plants, and the levels of salt accumulation in different types of soils. The main source of funding came from the Rio Grande Basin Initiative through the Texas Water Research Institute, matched by a local fund from El Paso Water Utilities. The Bureau of Reclamation USDI provided a fund through the Water Conservation Field Service Program to develop soil suitability guidelines, which is shown in a companion report. This report covers spray and soil salinity tolerance of landscape plants, and describes how the information can be used for assessing site suitability. Management capabilities of water users undoubtedly affect quality of landscape, and for this reason, it is an important factor in assessing site suitability. However, it is beyond the scope of this guideline. This project was assisted by a number of student workers from the University of Texas at El Paso. The task of preparing this report was assisted mainly by Doriana Torres and Yvette Pereyra, student workers. David Ornelas and David Tirre from El Paso Water Utilities have cooperated with our investigation of salt tolerance of landscape plants

Plant-Based Bioactive Natural Products: Insights into Molecular Mechanisms of Action

Medicinal plants have been used for the maintenance of human health since ancient times, in the form of food, spices, and traditional medicines. Medicinal plant-based traditional medicines serve as the primary healthcare systems in various countries even in recent times. Alongside this, medicinal plants have also served as the one of the main sources for the discovery of new therapeutic agents. At present, various plant extracts and their isolated phytochemicals are screened and evaluated for their diverse pharmacological activities related to both communicable and non-communicable diseases. However, comparatively little focus is given to the detailed mechanism of action of these agents on the molecular level. Molecular mechanism-based studies are essential for the development of evidence-based traditional medicines as well as for the development of isolated natural products as the lead candidates for novel drug discovery. This main focus of this Special Issue “Plant-based Bioactive Natural Products: Insights into Molecular Mechanisms of Action” is to cover the recent advances in science related to the molecular mechanisms of action of natural products. A total of nine articles were published in this Special Issue, including two original research articles and two review articles. This Special Issue has provided some new experimental data on bioactive natural products and their detailed mechanisms of action for biological activities. Similarly, review articles have provided state-of-the-art information on the related topics. I would like to thank all the authors for submitting their manuscripts and the reviewers and editors for their contribution to this Special Issue. Furthermore, I am also grateful to the handling editors and staffs of Applied Sciences for their support during the preparation and finalization of this Special Issue

Plant Biodiversity and Genetic Resources

The papers included in this Special Issue address a variety of important aspects of plant biodiversity and genetic resources, including definitions, descriptions, and illustrations of different components and their value for food and nutrition security, breeding, and environmental services. Furthermore, comprehensive information is provided regarding conservation approaches and techniques for plant genetic resources, policy aspects, and results of biological, genetic, morphological, economic, social, and breeding-related research activities. The complexity and vulnerability of (plant) biodiversity and its inherent genetic resources, as an integral part of the contextual ecosystem and the human web of life, are clearly demonstrated in this Special Issue, and for several encountered problems and constraints, possible approaches or solutions are presented to overcome these

Herbs and Spices

This edited volume, “Herbs and Spices”, is a collection of reviewed and relevant research chapters, offering a comprehensive overview of recent developments in the field of agricultural and biological sciences. The book comprises single chapters authored by various researchers and edited by an expert active in the medical research area. All chapters are complete in itself but united under a common research study topic. This publication aims at providing a thorough overview of the latest research efforts by international authors on herbs and spices, and opening new possible research paths for further novel developments