Conservation Of Plant Genetic Diversity Research Articles

Wild Seed Conservation in National Botanical Garden, Lalitpur, Nepal

Seed banks are the important means for the ex-situ conservation of plant genetic diversity. Though the seeds of domesticated varieties have been preserved for a long time, wild seed conservation is a noble concept in Nepal. Seed Bank of National Botanical Garden, Godawari, Lalitpur (NBG) is a major initiative for the conservation of wild plant seeds in Nepal. In the present study, a standardized seed banking procedures practiced at the Seed Bank of NBG, from seed collection to storage including germination test has been included. Currently, seeds of 84 wild species belonging to 77 genera of 47 families are preserved in the NBG. Alongside preserving wild genetic resources, NBG Seed Bank also provides materials for restoration, reintroduction and research that supports broader plant conservation goals, as well as contributes to education and public awareness about plant conservation.

Physiological and molecular aspects of seed longevity: exploring intra-species variation in eight Pisum sativum L. accessions.

Conservation of plant genetic diversity is fundamental for crop improvement, increasing agricultural production and sustainability, especially in the face of climatic changes. Although seed longevity is essential for the management of seed banks, few studies have, so far, addressed differences in this trait among the accessions of a single species. Eight Pisum sativum L. (pea) accessions were investigated to study the impact of long‐term (approximately 20 years) storage, aiming to reveal contrasting seed longevity and clarify the causes for these differences. The outstanding seed longevity observed in the G4 accession provided a unique experimental system. To characterize the biochemical and physical status of stored seeds, reactive oxygen species, lipid peroxidation, tocopherols, free proline and reducing sugars were measured. Thermoanalytical measurements (thermogravimetry and differential scanning calorimetry) and transmission electron microscopy combined with immunohistochemical analysis were performed. The long‐lived G4 seeds neither consumed tocopherols during storage nor showed free proline accumulation, as a deterioration hallmark, whereas reducing sugars were not affected. Thermal decomposition suggested a biomass composition compatible with the presence of low molecular weight molecules. Expansion of heterochromatic areas and reduced occurrence of γH2AX foci were highlighted in the nucleus of G4 seeds. The longevity of G4 seeds correlates with the occurrence of a reducing cellular environment and a nuclear ultrastructure favourable to genome stability. This work brings novelty to the study of within‐species variations in seed longevity, underlining the relevance of multidisciplinary approaches in seed longevity research.

Molecular genetic bases of seed resistance to oxidative stress during storage.

Conservation of plant genetic diversity, including economically important crops, is the foundation for food safety. About 90 % of the world’s crop genetic diversity is stored as seeds in genebanks. During storage seeds suffer physiological stress consequences, one of which is the accumulation of free radicals, primarily reactive oxygen species (ROS). An increase in ROS leads to oxidative stress, which negatively affects the quality of seeds and can lead to a complete loss of their viability. The review summarizes data on biochemical processes that affect seed longevity. The data on the destructive effect of free radicals towards plant cell macromolecules are analyzed, and the ways to eliminate excessive ROS in plants, the most important of which is the glutathioneascorbate pathway, are discussed. The relationship between seed dormancy and seed longevity is examined. Studying seeds of different plant species revealed a negative correlation between seed dormancy and longevity, while various authors who researched Arabidopsis seeds reported both positive and negative correlations between dormancy and seed longevity. A negative correlation between seed dormancy and viability probably means that seeds are able to adapt to changing environmental conditions. This review provides a summary of Arabidopsis genes associated with seed viability. By now, a significant number of loci and genes affecting seed longevity have been identified. This review contains a synopsis of modern studies on the viability of barley seeds. QTLs associated with barley seed longevity were identified on chromosomes 2H, 5H and 7H. In the QTL regions studied, the Zeo1, Ale, nud, nadp-me, and HvGR genes were identified. However, there is still no definite answer as to which genes would serve as markers of seed viability in a certain plant species.

Twenty Four Approaches for Conservation of Non-Orthodox Agricultural Plant Genetic Resources in Nepal

The conservation of plant genetic diversity underpins the future of agriculture, food and nutrition security and is critical to ensure the ability of future generations to cope with global environmental changes. The conservation efforts were more focused on orthodox crop species in Nepal before 2010. About 40% of agricultural plant genetic resources are non-orthodox, either recalcitrant/ intermediate type or vegetatively propagated plant species. Approaches for conservation of non-orthodox plant species differ from that of orthodox crops. Different conservation approaches have been established by National Agriculture Genetic Resources Center, Nepal for conserving non-orthodox agricultural plant species. We applied household survey, literatures survey, field survey, key informant survey and organized focus group discussion for assessing the different conservation approaches. A total of 24 approaches are being considered for conservation of non-orthodox plant species. Approaches under the ex-situ strategy are field genebank, botanical garden, city park, government farm, religious place, in-vitro culture and evolutionary plant breeding; under on-farm strategy are community field genebank, school field genebank, household field genebank, community/ public orchard, village level field genebank, geographical indication and participatory landrace enhancement, and under in-situ strategy are protected area, Ramsar site, world heritage site, community forest and legal protection for conserving non-orthodox plant species in Nepal. Field genebank is the very good approach, and it has been established in about 20 research stations. It should be extended to government farms and agriculture offices to conserve the local APGRs available in their respective command areas. Databases (passport and characterization) have been generated and will be available online to enhance the utilization in breeding, research and production. 

Organic acids, sugars, antioxidant activity, sensorial and other fruit characteristics of nine traditional Spanish Citrus fruits

The knowledge of the beneficial health properties of underutilised varieties of fruits is very valuable for the conservation of plant genetic diversity and agricultural development. The colour, weight, morphological parameters and total antioxidant activity (TAA) of the edible tissues of nine traditional Citrus fruits, three mandarin varieties, three lemon varieties, ‘Dulce’ lime, ‘Cimboba’ and ‘Blanco’ grapefruit was quantified. In addition, other fruit quality properties, such as organic acids and sugar concentrations in the Citrus juices were analysed, and the evaluation of organoleptic attributes, such as sweetness, aroma, firmness, lack of bitterness, overall impression and notable feature of fruits, was performed by a sensory panel. Results show significant differences among Citrus species and varieties of the analysed parameters. Analysis of the weight of the whole fruit and its edible tissues showed that the relative proportion of each fruit tissue was similar for all the studied Citrus species and varieties. on the other hand, ‘Autoctona’ mandarin and ‘Fino’ and ‘Sanguino’ lemons showed the highest TAA, while the ones most appreciated by consumers according to the sensory panel results were ‘Dulce’ lime followed by ‘Sanguino’ lemon, which could be due to their high fructose concentration and original colour, respectively. The utilisation of certain traditional Citrus species and varieties, such as’Mandarin’ and ‘Autoctona’ mandarins, ‘Sanguino’ lemon and ‘Dulce’ lime, of the south-east of Spain in future breeding programmes to increase agricultural biodiversity. In addition, the consumption of traditional varieties of Citrus fruits with high antioxidant activity would improve the beneficial effect of fruits in human health.

In Vitro Proliferation and Cryoconservation of Banana and Plantain Elite Clones

Abstract Agriculture and modern biotechnology are increasingly becoming interdependent, and many new techniques have brought new opportunities for enhancing production and marketing. Germplasm storage is an alternative for the conservation of plant genetic diversity, contributing to the improvement and maintenance of propagation programs for species of interest. In this work, banana corms were collected as plant material from relatively young commercial plantations of three different cultivars: ‘Williams’, Valery (AAA genome; Cavendish subgroup), and ‘Barraganete’ (AAB genome; Plantain subgroup). Their shoot tips were introduced into in vitro conditions, and subcultured monthly to obtain the required number of shoots. The shoots were subsequently rooted and stimulated to invigoration in order to extract apical meristems (0.8–1.0 mm), which were prepared for cryopreservion in liquid nitrogen (−196 °C) following pre-conditioning in PVS2 vitrification solution. Thereafter, the explants were rapidly thawed and then recovered and regenerated using two different methods – by Panis (2009) and Korneva et al. (2009) – consisting of two different sets of recovery and subsequent regeneration media. Statistical analysis of the results showed that the banana cultivar ‘Williams’ demonstrated higher survival and regeneration rates after cry-opreservation using the Korneva method, whereas in cultivars ‘Valery’ and ‘Barraganete’, there were no significant differences between the tested methods. The ‘Barraganete’ cultivar had the lowest survival and regeneration rates, regardless of the applied method.

Consequences of in-situ strategies for the conservation of plant genetic diversity

Conservation biologists have drawn up a range of guidelines for the conservation of genetic diversity—to maximise the chances that populations of threatened species persist, and to conserve this variation for its potential utility. However, our understanding of the effectiveness of conservation guidelines for maintaining genetic diversity in situ is limited. Furthermore, we lack information on how species-level variation in mating system affects these genetic conservation strategies. We used the British geographical ranges of eight widespread but declining plant species, varying in breeding system, as a model to assess the effectiveness of guidelines for the in-situ conservation of neutral genetic diversity. By applying simulated in-situ conservation scenarios to amplified fragment length polymorphism data, we show that the conservation of one population (the “minimum-set” approach) would retain ~70% of common allelic variation, but few or no rare alleles (alleles with frequency≤0.05). Our results indicate that the conservation of >35% of populations would be needed to reach the Convention on Biological Diversity's recommendation to conserve 70% of genetic diversity in situ, as applied to rare alleles (~10 populations within each species' British range). The capture of genetic variation in simulated conservation networks was insensitive to breeding system. However, a spatially stratified approach to population selection led to significantly greater capture rates for common alleles in two of our study species, relative to a spatially random strategy. Our study highlights the challenges of conserving genetic variation, and emphasises the vulnerability of genetic biodiversity to reductions in the extent of species' ranges.

An Application of Molecular Tools in Plant Genetic Diversity Conservation

The conservation and use of plant genetic diversity are essential to the continued maintenance and improvement of agricultural and forestry production and thus, to sustainable development and poverty alleviation. The dramatic advances in molecular genetics over the last decade years have provided workers involved in the conservation of plant genetic diversity with a range of new techniques. Molecular tools, such as molecular markers and other genomic applications, have been highly successful in characterizing existing genetic variation within species, which generates new genetic diversity that often extends beyond species boundaries. The objectives of this article are to review the molecular basis on plant genetic diversity conservation and summarize the continuously rising and application of molecular tool. Then, we look forward and consider the significant of application of molecular tools in plant genetic diversity conservation.

From Villous Strawberry Shams to Hairy Huckleberries: The Wild Side of Berry Exploration

The U.S. Department of Agriculture (USDA), Agricultural Research Service, National Clonal Germplasm Repository in Corvallis was established as the U.S. National Plant Germplasm System's berry genebank in 1981. Since then, the USDA has sponsored numerous explorations throughout the United States and foreign countries to obtain berry plant genetic resources. Species of Fragaria L. (strawberries), Ribes L. (currants and gooseberries), Rubus L. (raspberries and blackberries), and Vaccinium L. (blueberries and cranberries) are native to both domestic and international localities. With limited gene pools for cultivated strawberries, raspberries, and blackberries, expeditions have provided a wealth of genetic resources to expand opportunities for breeders to develop new cultivars. Particularly given the diverse species inherent in the development of cultivated blueberries, these trips have discovered unusual new blueberry relatives and forms available for expanding the range of production, increasing plant yields, and improving fruit antioxidant content. Along the way, new fruit species and new uses for known species were observed. Gathering the bounty of the world's berries resulted in encounters with diverse fauna, from snakes, bears, and bison to butterflies, mosquitoes, ticks, and chiggers. Avenging Toxicodendron species have added their mark on intrepid explorers. Remote sites with nothing but clear night stars and the satellite markers on the global positioning system offer radiant beauty and an abiding hope for the conservation of plant genetic diversity for all people for all time.

Centaurea species in Turkey (A): Centaurea odyssei Wagenitz (Asteraceae) in Kazdagi (Mt. Ida) National Park

Kazdagi (Mt. Ida: 1774 m) is in northwestern Turkey. The rock type is mainly schist, and the soil is brown forest soil without lime. For these reasons, Kazdagi is one of the most important floristic areas in Turkey. With regard to genetic resources, this area is of major importance for in situ conservation of plant genetic diversity. Centaurea odyssei Wagenitz is a threatened very local endemic species, growing only in three small areas on Kazdagi. These populations are under heavy grazing stress. Morphological, anatomical and palynological studies are described and autecological and conservation aspects of the species are discussed.

Benefits of Conservation of Plant Genetic Diversity to Arthropod Diversity

Abstract:  We argue that the genetic diversity of a dominant plant is important to the associated dependent community because dependent species such as herbivores are restricted to a subset of genotypes in the host‐plant population. For plants that function as habitat, we predicted that greater genetic diversity in the plant population would be associated with greater diversity in the dependent arthropod community. Using naturally hybridizing cottonwoods ( Populus spp.) in western North America as a model system, we tested the general hypothesis that arthropod alpha (within cross‐type richness) and beta (among cross‐type composition) diversities are correlated with cottonwood cross types from local to regional scales. In common garden experiments and field surveys, leaf‐modifying arthropod richness was significantly greater on either the F1 (1.54 times) or backcross (1.46 times) hybrid cross types than on the pure broadleaf cross type ( P. deltoides Marshallor P. fremontii Watson). Composition was significantly different among three cross types of cottonwoods at all scales. Within a river system, cottonwood hybrid zones had 1.49 times greater richness than the broadleaf zone, and community composition was significantly different between each parental zone and the hybrid zone, demonstrating a hierarchical concentration of diversity. Overall, the habitats with the highest cottonwood cross‐type diversity also had the highest arthropod diversity. These data show that the genetics of habitat is an important conservation concept and should be a component of conservation theory.

Conservation of plant genetic diversity in India: The role of Botanic gardens in the new millennium

At present we are passing through a global biological extinction due to various factors. Plants are one of the key constituents of the ecology. Human life is dependent on plants for fulfilling basic needs- food, shelter and medicine. We are losing tropical forests at a rate of 50 hectares per minute and, as a result, one plant species is becoming extinct every day on an average. Flora of Indian subcontinent is very rich in diversity and endemism. India has an estimated 16,000 vascular plants; 5,000 endemic species distributed into different biogeographic zones. These zones have a unique diversity climatically, geographically and biologically which are the habitat of tropical evergreen and alpine-arctic vegetation. But paradoxically, 10-15% of the Indian flowering plants are under various degrees of threat. Nevertheless, 25% will become rare by the turn of the century unless proper conservation measures are taken. Botanic Gardens serve as a repository of germplasm collection and ex-situ conservation of plants especially rare and endangered ones of indigenous and exotic origin. Each Botanic Garden should play a significant role in preserving genetic diversity and to ensure sustainable utilization of the species as spelt out by IUCN, IABG, and BGCI. Cumulative efforts are to be initiated for providing required microclimate to the individual plant species for their conservation. Surveys should be carried out for ascertaining the population of the threatened species in nature from time to time. Ex-situ conservation of the rare and endangered species in the Botanic Garden, their multiplication and, ultimately, rehabilitation in the nature would be the most effective strategy for the conservation of the plant genetic diversity in the new millennium.

Property rights issues involving plant genetic resources: implications of ownership for economic efficiency

The economic theory of property rights is applied to the issue of the conservation of plant genetic diversity, an issue often discussed in terms of benefit sharing, in order to demonstrate that the assignment of property rights is important for reasons of efficiency as well as for equity. Given the existence of transaction costs within an industry, the location of a property rights assignment is a crucial factor determining the incentives for efficient levels of investment at various levels of that industry. In the context of plant genetic resources, this means that property rights that are located at the retail end of the pharmaceutical and plant breeding industries may not have sufficient effect to generate the incentives to supply adequate amounts of plant genetic resources to the research and development sectors at the base of these industries.

Mapping the geographical distribution of genetic variation in the genusLensfor the enhanced conservation of plant genetic diversity

Plant genetic resource conservation strategies, informed by an understanding of the geographical distribution of genetic variation within species, are likely to result in a wider representation of conserved diversity inex situgene banks andin situgenetic reserves. The main objective of this study was to map the geographical distribution of genetic variation, as revealed by randomly amplified polymorphic DNA (RAPDs), in four wild relatives of the cultivated lentil, namelyLens culinarisssp.orientalis, L. odemensis, L. ervoidesandL. nigricans. Areas of high diversity and unique diversity were located for each taxon, and regions where further germplasm collection was most likely to yield novel genetic variation were identified. There were centres of diversity forL. culinarisssp.orientalisin southeast Turkey and northwest Syria, and in south Syria and Jordan. A centre of diversity was found to exist in Sweida province, south Syria, forL. odemensis, and forL. ervoidesalong the coastal border region between Syria and Turkey stretching down along the Syrian coast. There was a centre of diversity forL. nigricansin west Turkey. Analytical techniques previously used at the species level were found to be useful at the genotypic level to objectively target areas for future collection missions, to increase diversity inex situcollections and to target areas forin situconservation.