National Germplasm Research Articles

The national germ plasm movement

Molecular Reproduction and DevelopmentVolume 79, Issue 12 p. Fm i-Fm i EditorialFree Access The national germ plasm movement Gary M. Wessel, Gary M. WesselSearch for more papers by this author Gary M. Wessel, Gary M. WesselSearch for more papers by this author First published: 11 December 2012 https://doi.org/10.1002/mrd.22140AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume79, Issue12December 2012Pages Fm i-Fm i RelatedInformation

Swimming in the Breeding Pool: Partnering for Conservation of Plant Genetic Resources through Crop Germplasm Enhancement

Substantial and sustainable increases in productivity of all crops are needed to meet the predicted demand for food, feed, fibres, flowers, fuels, fun, feed-stocks and pharmaceuticals of this 21st century bio-based economy. Plant breeding is vital for protecting the yield gains made to date, and for further increasing the genetic yield potential of all crops. As a result of the Green Revolution, global productivity of the main food staples steadily rose since the 1960s. Such achievements ensued from crop genetic enhancement partnerships. They are models for illustrating partnering for exchange, evaluation, release and use of plant genetic resources worldwide. These partnerships include national agricultural research institutes and international agricultural research centres. For many decades the global wheat yield increased due to an effective International Wheat Improvement Network (IWIN), which deployed cutting-edge science alongside practical multi-disciplinary applications, resulting in the development of bred-germplasm that has improved food security and the livelihoods of farmers in the developing world. IWIN operates field evaluation trials in more than 250 locations of 100 countries for testing breeding wheat lines across many environments. The International Network for Genetic Evaluation of Rice (INGER) has become an integral component of rice breeding programmes: every year partners provide about 1000 genetically diverse breeding lines, which have been grown in about 600 experiment stations from 80 countries. The Latin American Maize Programme (LAMP) has assessed national germplasm, facilitated the exchange of genetic resources across the continent, and its core subset has been made available to encourage further use in broadening maize genetic resources. For example, the Germplasm Enhancement of Maize (GEM) project has used LAMP-selected landraces in crosses with elite temperate maize lines provided by North American private companies, to introgress useful genetic diversity into US maize germplasm, with the aim to broaden the genetic base of “corn-belt” hybrids.

Notice of Release of Bounty Germplasm Big Bluestem: A Selected Class of Natural Germplasm

Bounty Germplasm big bluestem ( Andropogon gerardii Vitman [Poaceae]) is a selected class of natural germplasm release for use in conservation cover, erosion control, pasture and hayland, wildlife habitat, prairie revegetation, rangeland seeding, and landscaping in the Northern Great Plains and Upper Midwest of the US. Originating from native stands in Minnesota and eastern South Dakota, this selection is expected to perform well throughout Minnesota, the eastern Dakotas, and surrounding regions.

First Report of Citrus tristeza virus in National Germplasm of Citrus in Afghanistan.

Rejuvenation of the horticulture industry is a government priority in Afghanistan. With that purpose, European Commission-supported programs specifically focus on greater access to improved and appropriate planting materials to increase the quantity and quality of more competitive horticultural products. Establishment of a biotechnology laboratory was considered essential support to horticulture sector development. This laboratory has begun screening the health status of the Afghan Germplasm National Collection to ensure multiplication of not only the best selected varieties or ecotypes but also to avoid reproduction and distribution of virus-infected fruit trees. Symptom inspection and sample collection for viral diseases was carried out in the citrus orchard during survey activity at the National Collection Experimental Farm in Jalalabad (Nangarhar Province). Ninety-nine variety plots (one row of five plants) were inspected visually and samples from two plants for each plot were collected and analyzed by double-antibody sandwich (DAS)-ELISA. Plants showing vein flecking, yellowing, and plant decline symptoms were observed in several plots. Four accessions were found to be infected by Citrus tristeza virus (CTV): kumquat cv. Margarita (isolates J4 and J8), orange cv. Mahali (J61), mandarin group cv. Fruter (J76), and rough lemon cv. Mahali (J101). Identified isolates have been characterized molecularly. A 655-nt fragment, corresponding to the major coat protein gene, has been amplified from all ELISA-positive samples by reverse transcription (RT)-PCR using CTVF (5'-TAATGGACGACGAACAAAGA-3') and CTVR (5'-CCAAGCTGCCTGACATTAGT-3') primers. Sequence analysis revealed high similarity, ranging from 91.1 to 99.8%, within CTV isolates detected in Jalalabad. In accordance with the phylogenetic groups previously defined (page 8 in: Proceedings of the 15th Conference of the International Organization of Citrus Virologists, 2002), nucleotide sequences of Afghan CTV isolates investigated in the current work cluster in Group 1 (J4 and J8), Group 4 (J61 and J76), and Group 5 (J101). In particular, J4 and J8 isolates show, respectively, identity of 99.4 and 99.2% with reference isolate T36 (GenBank Accession No. M76485) from the United States (Florida). Moreover, in Group 4, isolate J61 and J76 were more similar to ANO-1 isolate (GenBank Accession No. DQ211658) from Egypt (identity of 98.5 and 98.0%, respectively) than to isolate 443-4 (GenBank Accession No. AY791844) from Croatia (97.4 and 97.5%, respectively). Finally, isolate J101 in Group 5, shows identity of 95.6% with isolates C268-2 (GenBank Accession No. AY750770) and C269-6 (GenBank Accession No. AY750775) from Argentina. To our knowledge, our results identified for the first time CTV-infected plants in Afghanistan. The presence of CTV in four accessions of the national citrus collection is of concern for Afghan horticulture. Implementation of the certification schemes is therefore necessary to guarantee the production and the employment of virus-free propagating material.

Assessing genetic diversity of perennial ryegrass (Lolium perenne L.) from four continents by inter-simple sequence repeat (ISSR) markers

In this study, inter-simple sequence repeat (ISSR) markers were used to compare genetic diversity between commercial cultivars and natural germplasm which were obtained from Europe, Africa, Asia, and North America. There was a relatively high genetic variation in the whole collection judged by the polymorphism rate (97.16%), Nei's gene diversity (0.28), and Shannon's information index (0.44). Results indicate lower genetic diversity in commercial cultivars than natural germplasm. The European group showed the highest genetic diversity. The genetic distance (GD) between cultivars ‘Exacta’ and ‘ABT-99- 4.560’ was the closest (0.19), while largest GD occurred between ‘PI 632472’ and ‘PI 547390’ (0.85). Based on Jaccard’s similarity coefficient, 12 groups were distinguished with a cut-off point at 0.44. Using the concept of core collection, we suggested ‘Headstast 2’, ‘PI 598909’, ‘Catalina II’, ‘PI 538976’, ‘PI 598440’, ‘PI 610925’, ‘PI 598877’, ‘PI 516605’, and ‘PI 619554’ be included in a core collection of germplasm to accommodate maximum genetic diversity. Key words : Genetic distance, genetic erosion, unweighted pair group method with arithmetic mean (UPGMA), cluster analysis, germplasm.

DEVELOPMENT OF IN VITRO PROPAGATION AND CONSERVATION PROTOCOLS OF THE NATIVE BRAZILIAN MANGABA TREE

DEVELOPMENT OF IN VITRO PROPAGATION AND CONSERVATION PROTOCOLS OF THE NATIVE BRAZILIAN MANGABA TREE

Collecting in Central Asia and the Caucasus: U.S. National Plant Germplasm System Plant Explorations

The USDA-ARS National Plant Germplasm System is charged with the preservation of economically important crop plants and their wild relatives. Curators in the System strive to develop collections capturing the genetic diversity of each species. One mechanism for filling gaps in collections is through plant exploration. The USDA-ARS National Germplasm Resources Laboratory, Plant Exchange Office administers funding and coordinates plant explorations for the System. In the past decade, there have been 38 collecting missions in Central Asia and the Caucasus. This area is rich in plant biodiversity and is a center of diversity for many crop species and their wild relatives. The author has had the opportunity to participate in four explorations in the area focusing on wild crop relatives. This included a trip to Kazakhstan targeting Russian dandelion, Taraxacum kok-saghyz L.E. Rodin, a source of natural rubber. In this mission, a total of 22 accessions of T. kok-saghyz and six accessions of other Taraxacum species were collected.

Intraspecific variation of physiological and molecular response to cadmium stress in Populus nigra L.

Little is known about the variability of response to heavy metal stress within tree species, although it could be a key for a better understanding of tolerance mechanisms and for breeding. The aim of the present study was to characterize the natural variation of response to cadmium (Cd) in Populus nigra L. in order to understand the mechanisms of Cd tolerance. For that, two P. nigra genotypes, originating from contrasting environments in northern (genotype 58-861) and southern (genotype Poli) Italy, were exposed to Cd stress in hydroponics for 3 weeks. The effect of stress was estimated by measuring biomass production, photosynthetic performance and accumulation and translocation of Cd at the end of the experiment. To better understand the mechanisms of Cd tolerance, the expression of some candidate genes involved in the ascorbate-glutathione cycle (ascorbate peroxidase, glutathione reductase, glutathione S-transferase) and in metal sequestration (metallothioneins) was analyzed in leaves. Biomass production and photosynthesis were affected by the treatment in both clones but the southern clone was markedly more tolerant to Cd stress than the other. Nevertheless, the Cd content in leaves was not significantly different between the two clones and was quite low compared to other species. The content of thiols and phytochelatins (PCs), associated with the transcription profile of the glutathione S-transferase gene, indicated relevant differences in the use of the PCs pathway under Cd stress, which could explain the different tolerance to Cd. The northern clone accumulated thiols but down-regulated the GST gene, whereas the southern clone accumulated PCs and up-regulated the GST gene, which can be useful to complex and detoxify Cd. These results suggest that the glutathione pathway is involved in the differential Cd tolerance of the two genotypes. The natural germplasm of P. nigra represents a valuable resource for understanding tolerance to Cd and for selection of plant material for phytoremediation.

Spatial Analysis of Avocado Sunblotch Disease in an Avocado Germplasm Collection

AbstractAvocado sunblotch viroid (ASBVd) causes an important disease of avocado, Persea americana. Symptoms of avocado sunblotch were first observed in the avocado germplasm collection at the National Germplasm Repository in Miami in the early 1980s; however, the extent of infection was unknown. An ASBVd‐specific reverse transcription polymerase chain reaction (RT‐PCR) protocol was developed in 1996 and used to screen every tree in the collection. Surveys in 1996 and 2000 found that although 23 newly infected trees were detected, the proportion of ASBVd‐positive accessions remained unchanged at 19%. However, in a 2009 survey, 50 newly infected trees were detected for an overall infection rate of 21%. Results of spatial analyses indicate that for the older plantings, the effective range of spread increased more than threefold during the 13 year span, while in the newer plantings, the pattern of infection indicates a reintroduction of the viroid rather than natural spread. Despite strict sanitization procedures in field and greenhouse operations, ASBVd infections have increased in the USDA collection. Although genetic diversity in the collection would be reduced, eliminating all ASBVd‐positive plants may be necessary to ensure that other accessions in the collection do not become infected.

Notice of Release of Majestic Germplasm and Spectrum Germplasm western prairie clover: selected class of natural germplasm

Two natural-track selected germplasms of western prairie clover (<i>Dalea ornata</i> (Douglas ex Hook.) Eaton &amp; J. Wright [Fabaceae]) have been released for use in revegetation of semiarid rangelands in the western US. Western prairie clover is a perennial leguminous forb that occurs naturally in Idaho, Washington, Oregon, California, and Nevada. Majestic Germplasm western prairie clover originates from seed collected from indigenous plants near Sherar’s Bridge in Sherman County, Oregon, whereas Spectrum Germplasm western prairie clover originates from seed collected from indigenous plants near Succor Creek Natural Area in far eastern Oregon in Malheur County, Oregon. Common-garden and DNA data for 22 collections of western prairie clover were used to develop these releases on a genetic basis. Majestic Germplasm was selected to represent the genetic diversity structure of western prairie clover from the western Columbia Plateau and western Blue Mountains Ecoregions. Spectrum Germplasm was selected to represent the genetic diversity structure from the central and eastern Columbia Plateau, central and eastern Blue Mountains, Northern Basin and Range, and Snake River Plain Ecoregions. This is a new species in the commercial seed trade, and these are the first releases of this species.

Notice of Release of Prairie Harvest Germplasm Common hackberry: selected class of natural germplasm

Prairie Harvest Germplasm common hackberry <i>(Celtis occidentali</i>s L. [Ulmaceae]) is a selected class of natural germplasm released for use in conservation plantings in the Northern Great Plains and Upper Midwest of the US. Originating from native trees located in Polk County, northwestern Minnesota, this northern selection is winter hardy with improved form and growth rates. This germplasm release is recommended for conservation use as a tall tree in windbreaks, wildlife areas, and riparian plantings. Prairie Harvest Germplasm represents the first northern source release of common hackberry for conservation use in the northern regions of Minnesota and North Dakota.

Establishment of core collection for Chinese tea germplasm based on cultivated region grouping and phenotypic data

Tea is an important economic crop in China. About 2665 accessions of tea germplasm (Camellia spp.) are conserved in the China National Germplasm Tea Repository. However, only a small fraction of the collections have been exhaustively used in tea plant improvement programs. The objective of the present study was to develop a core collection of tea plant to enhance the utilization of genetic resources in improvement programs and simplify their management. For this purpose, based on the cultivated region grouping and phenotypic trait data, a core collection of tea plant was established using logarithm proportion and Ward’s cluster method. Approximately 20% of the accessions were then randomly selected from these distinct groups to form a core collection of 532 accessions. Different statistical methods including comparison of mean using Newman-Keuls test, variance using Levene’s test, and frequency distribution using Chi-square test for the traits validated that the variation present in the initial collection was retained in the core collection. The Shannon-Weaver diversity index for different traits was also similar in the core and initial collection. The phenotypic correlations among different quantitative traits that may be under the control of coadapted gene complexes were also preserved in the core collection. This core collection will play an important role in the utilization of tea germplasms.

Notice of Release of Vintage Germplasm Common Elderberry: A SELECTED CLASS OF NATURAL GERMPLASM

A selected germplasm of common elderberry ( Sambucus nigra L. ssp. canadensis (L.) R. Bolli [Caprifoliaceae]) has been released for intended use in streambank stabilization and improvement of wildlife habitat in the Great Lakes region.

Genotypic and phenotypic diversity in Finnish cultivated sour cherry (Prunus cerasus L.)

The Finnish national sour cherry germplasm collection was established in the end of 1980s following collection missions in Southern Finland. The original plantation consisted of 122 trees representing 77 accessions of locally adapted cherry material. Cultivar names of the collected samples were not known, and they were registered according to the collection site. Phenotypical observations according to the Nordic Genebank instructions were recorded in 1992, 1993 and some repetitions were made in 2003. In 2005 leaf samples were collected from the 52 still remaining accessions for a microsatellite (SSR) DNA marker analysis. DNA analysis distinguished 28 genotypes within the studied material. Two large groups of accessions sharing identical genotype, consisting of 18 and 20 accessions, were detected, one in the amarelle and one in the morello–cultivar group, respectively. Several cultivar group specific SSR markers were found. Clustering analysis of the phenotypical characteristics supported the division into two cultivar groups. Replicate trees of one accession, or accessions representing one SSR genotype, clustered together only occasionally indicating some level of plasticity in the observed descriptors. Our findings indicate that only a few sour cherry clones have been successful and commonly distributed in Finland. The results were taken into account when selecting accessions for long term conservation in the national germplasm collection.

Pitiüsa–Ibicenca goat conservation program: Current status

The Ibicenca or Pitiüsa goat is the most endangered goat breed of Spain. This breed occurs only on the Pitiüse islands (Ibiza and Formentera), with fewer than 147 animals on 17 different farms, indicating a clear risk of extinction. In response to this condition, a program to rescue the breed was initiated, involving: (1) the characterization of morphological variables of the breed, (2) the genetic characterization of the breed and (3) the initiation of an ex situ preservation program securing the participation of farmers, linked to the germplasm bank network of Spain. This paper describes the genetic characterization and ex situ plans that have been thus far developed. Genetic characterization, based on neutral allelic variation (using 27 microsatellite markers), was conducted along with 12 other goat breeds from Spain, all with known characterization, to serve as referential breeds for assessing the status of the Ibicenca or Pitiüsa goat in the current context of goat genetic resources of Spain. The ex situ program was initiated by selecting unrelated bucks and training them to produce semen for conservation purposes. Results from the genetic characterization showed that the Ibicenca or Pitiüsa goat is a single genetic entity, and is more related to Continental breeds of Spain than to breeds from the other Balearic islands. This finding justifies its conservation by means of cryopreservation of semen. The ex situ plan obtained 384 semen doses from 3 sires collected in the Pitiüse islands, which are to be used in AI programs in the future. These samples were stored in two replicates: one at the Regional Germplasm Bank of Mallorca Island for Mallorca breeds and the second, as a backup, at the Spanish National Germplasm Bank located in Madrid. The implementation of this plan, in particular the establishment of an ex situ conservation condition, prevents the potential risk of extinction faced by this breed. The plan well accepted by farmers will be linked to research on the production and adaptive traits of the breed to identify attributes that could potentially enhance its economic value and allow its population expansion in situ.

Is ex situ Conservation Suitable for Calligonum L.? A Research Program in Turpan Eremophyte Botanical Garden

In this study, we observed the flowering phenology, breeding system, pollination and seed germination of four species of Calligonum (Polygonaceae) (C. calliphysa, C. rubicundum, C. densum and C. ebinuricum) in Turpan Eremophyte Botanical Garden, China. Our results showed that the species had overlapping flowering phenologies and were pollinated by similar pollination agents. Their breeding systems were self-compatible, and with signs of outbreeding, but not of hybridization with each other. They also had high seed germination rates. Therefore, they are suitable to ex situ conservation in the Turpan Eremophyte Botanical Garden, and can supply sufficient seeds for renewal population and conservation of germplasm resources. These results provide theoretical support to the construction of a national germplasm resource garden of Calligonum.

DATE PALM GENETIC DIVERSITY CONSERVATION FOR SUSTAINABLE PRODUCTION

DATE PALM GENETIC DIVERSITY CONSERVATION FOR SUSTAINABLE PRODUCTION

Notice of release of Catarina blend bristlegrass: selected class of natural germplasm

Four selected germplasms of bristlegrass ( Setaria vulpiseta (Lam.) Roem. & Schult. and S. leucopila (Scribn. & Merr.) K. Schum. [Poaceae]) have been released for rangeland plantings and wildlife habitat enhancement plantings in the Rio Grande Plain of Texas. Catarina blend bristlegrass is a mix of 4 bristlegrass releases (Kika648 Germplasm, Kika819 Germplasm, Kika820 Germplasm, and Kika677 Germplasm) selected from an extensive evaluation at multiple sites in south Texas. Accessions included in the blend are increased in isolation and blended prior to sale in order to maintain the genetic integrity of each release. These germplasms represent the first commercially available release of bristlegrass that has been tested and is adapted to south Texas.

Notice of release of Welder Germplasm shortspike windmillgrass: selected class of natural germplasm

John Lloyd-Reilley, Shelly D Maher, William R Ocumpaugh, Paula D Maywald and Forrest S Smith

Notice of release of Webb Germplasm whiplash pappusgrass: selected class of natural germplasm

A selected germplasm of whiplash pappusgrass ( Pappophorum vaginatum Buckley [Poaceae]) has been released for rangeland seeding, saline soil revegetation, and wildlife habitat restoration plantings in south Texas. Webb Germplasm whiplash pappusgrass is a blend of 3 accessions selected from an evaluation at multiple sites in the intended area of use. Selections were made based on visual evaluations of plant characteristics and germination tests of seed collected from each location. Following selection, components of the germplasm were increased in isolation and blended following harvest to ensure inclusion of seed of each selected accession. Accessions included in the blend originate from 3 counties and distinct soil types. This germplasm represents the first commercial release of a whiplash pappusgrass ecotype originating from south Texas.