Micropropagation supports reintroduction of an apulian artichoke landrace in sustainable cropping systems

Artichoke (Cynara cardunculus L. var. scolymus (L.) Fiori) is a perennial plant of the Aster-aceae’s family native to the Mediterranean basin. Italy has rich artichoke biodiversity, but many landraces are subjected to genetic erosion caused by increasing use of commercial varieties that are more homogenous in production. An Apulian landrace ‘Troianella’ was established in vitro to valorize and provide high-quality material for propagation in nurseries and, subsequently, for cultivation in production fields. The shoot proliferation was tested on four different growth media, adding cytokinin (-6-benzylamminopurine (BAP-0.05 mg L−1 ). Among these, the best results were achieved on MS519-A and BM media in which MS macronutrients were supplemented with additional doses of CaCl2 and MgSO4 (plus 120 mg L−1 and 190 mg L−1, respectively). In vitro root induction was obtained with 10 mg L−1 of Indole-3-acetic acid (IAA) and 30 g L−1 of sucrose. Plants derived from tissue culture were acclimatized in greenhouse using mycorrhizal symbiosis to increase survival during the acclimatization phase and to improve their performance after transplanting in field. Three arbuscular mycorrhizal (AM) fungi (Septoglomus viscosum, Funelliformis mosseae, and Symbivit, a commercial mix) were added to a sterile substrate and compared to a sterile control without any AM fungal inocula. After 3 months, the best growth and plant appearance were on substrates with S. viscosum fungus or the commercial mycorrhizal fungi mix. The results supported a development of an efficient micropropagation protocol and a production of high quality plant material for sustainable farming of the endangered ’Troianella’ landrace

Sterilization procedures and Plant Preservative Mixture on in vitro establishment of Miscanthus sinensis Andersson.

Information about the establishment phase of Miscanthus sinensis Andersson as sterile procedure to avoid the contamination were few reported. The aim of this study was to evaluate different immersion sterilization procedures with and without the biocide, Plant Preservative Mixture (PPM?) on in vitro contamination of two Miscanthus genotypes. The plant material were canes from adult plants of two accessions PI 668371 and PI 668375 cultivated in the germplasm bank of USDA-ARS, Griffin, Georgia. Apical meristems were submitted to immersion sterilization procedures (70% isopropyl alcohol and 1.5, 5.0 or 8.25% NaOCl for different time periods, followed by rinsing three times with autoclaved distilled water. After that, the explants were inoculated on MS basal medium in the presence or absence of 1 mL L-1 PPM?. The experimental design was fully randomized in a 2 x 5 x 2 factorial scheme (genotypes x sterilization process x PPM?) with five replicates per treatment and five apical meristems per experimental unit. Aseptic treatments showed no differences for percentage of bacterial and fungal contaminations and percentage of explant survival. In the presence of PPM ? there was less bacterial contamination in the accessions (28%) than in the absence (100%). For the percentage of fungal contamination, PPM ? had no significant effect on PI 668371 accession. However, on PI 668375 accession there was a lower percentage of fungal contamination (16%). The biocide PPM ? may be an efficient agent to prevent bacterial contamination on in vitro cultures of Miscanthus spp and fungal contamination in PI 668375 accession

Operational cryopreservation of multi-genera plant genetic resources collections at the National Center for Genetic Resources Preservation

The U.S. National Center for Genetic Resources Preservation (NCGRP) is focused on research associated with the long-term preservation of plant and animal genetic resources in conjunction with the long-term storage of these resources. The Center securely stores over 730,000 inventories of plant genetic resources, the majority consisting of the base collection for the National Plant Germplasm System (>480,000 inventories). These collections are predominately seed which is dried to between 6% - 10% moisture content and stored at -18oC. However, ~8% of this base collection is stored in the vapour phase of liquid nitrogen. The criteria of which accession to store in liquid nitrogen and which to store conventionally (-18oC) is largely made on a genus-by-genus basis and usually crypreservation is not considered for large sized see and seed with high oil content. Germination of every seed accession which is considered for liquid nitrogen storage is tested both with and without a 24 hour liquid nitrogen exposure to ensure that a particular accession can tolerate liquid nitrogen exposure. In addition to the seed accessions stored at the NPGRP, we also have a large program in the operational storage of vegetatively-propagated accessions in the National Plant Germplasm System. At present, many of these accessions are maintained in a single field site and only ~10% of the 30,000 vegetatively-propagated accessions in the National Plant Germplasm System are backed up in cryopreservation. Due to the very high labour requirements for cryopreserving clonal germplasm collections (20-40 accessions/person/year), the NCGRP has operationally developed a priority system based on existing technology to determine which crops to process for long-term storage. Practically, our efforts are concentrated on crops with developed cryopreservation methods and where support of the crop curator is available. Examples of this collaboration include: 1. Apple (and sour cherry), where a robust dormant bud cryopreservation technology exists. Over 2,500 apple accessions are in cryostorage at NCGRP yet all phases of this work are dependent on the curator doing all grafting to test post-cryo viability as well as carrying out the monitor testing over time. 2. Garlic, where shoot tips are cryopreserved from field grown bulbs. The quantity of bulbs and number of accessions cryopreserved per year is very much dependent on the curator s ability to do the field work. 3. Accessions that require tissue culture plantlets as a source of the shoot tips (mint, strawberry, currents, blackberries, hops, sweet potato, pear). The NCGRP currently does not have the resources to do the isolation and establishment of the shoot cultures and therefore the curator must be willing to do this work in order to have the crop cryopreserved. Operationally, our criteria for having an accession successfully back-up in cryostorage are a minimum of 40% viability in the cryopreserved shoot tips and a minimum 60 viable shoot tips cryostored. For most crops, we store 10 shoot tips/cryo vial and with the criteria for success mentioned above, we have a 99% chance of having at least one viable shoot tip per vial. Fortunately, for the crops we work with, vial-to-vial variability is very low. Research in our operational setting focuses on applying existing techniques to our accessions and laboratory. Often, we need to make minor modifications in techniques so that the techniques are applicable in our system. This research phase may take 1-2 years before we consider a technique for a crop ready to start on a large-scale germplasm preservation project. Banana is a crop in this category in our laboratory where very good existing techniques exist yet it takes time to fully implement them into our operational system. Another area of research in our applied preservation setting is extension of the apple dormant bud cryopreservation system to other woody crops. A major determinant for this research is the relative ease of preserving entire collections if dormant buds can be cryopreserved. This operational research approach was only initiated two years ago but we already have initial success with butternut and preliminary data indicates that material from our warmer-winter sites where vegetatively-propagated material is grown (west coast of the U.S.) can be cryopreserved as well as from colder growing regions. The focus crops for this research include a Prunus program (apricot, almond, peach, sweet cherry and plum), walnut, pear, hazelnut, blueberry, pomegranate and pistachio.vokMyynti: MTT, Tietopalvelut 31600 Jokioine

Salix

Willow (Salix L.) species have good qualities for becoming a biomass crop for production of biofuels. They grow on marginal soils, produce high yields of wood in a short period of time, and are easily propagated. Salix is one of the few genera that may be cryopreserved as dormant winter buds (DBs) instead of using tissue culture techniques. The objective of our study was to evaluate selected factors that affect cryotolerance of nine Salix germplasm accessions in the USDA‐ARS National Plant Germplasm System collection. One‐year‐old branches harvested in January over 3 yr were cut into either 6‐ to 7‐ or 10‐cm segments containing at least two DBs. Segments were treated with a slow‐cooling procedure and stored in vapor‐phase liquid N (LNV). Control segments were stored at −5 °C until planting. The LNV‐exposed and the −5 °C‐stored nodal segments were warmed and directly planted in a cold greenhouse. Six weeks later, the material was evaluated for shoot and root development. Segments that developed a shoot were considered viable. Average viability varied among years (0–35.1%) even for the same accession, species (4.2–51.4%), and segment length. Dormant buds on 10‐cm segments had higher average viability (82.2%) than did DBs on 6‐ to 7‐cm segments (43.9%), suggesting higher suitability for cryopreservation. In the material studied, Salix DB viability was correlated with branch diameter, DB density, and the ability to develop shoots and roots prior to cryopreservation

Crop Registration: The Pathway to Public Access of Plant Genetic Materials to Build Crops for the Future

Starting in 1926 and continuing for 80+ yr, 11,241 crop genetic materials have been registered as of 31 Dec. 2008. The crop registration process is an important pathway to publically describe and document new and useful genetic materials and to incorporate these into the public domain via the National Plant Germplasm System (NPGS). Crop Registration materials are now searchable via the Germplasm Resources Information Network (GRIN) and demand for registered materials remains strong with more than 9150 registered accessions distributed in the past 26 yr by the NPGS. Guidelines continue to evolve to accommodate global factors effecting germplasm exchange such as Intellectual Property Rights (IPR) and international treaties (i.e., The International Treaty on Genetic Resources for Food and Agriculture). Together with (i) the advent of the new Journal of Plant Registrations; (ii) the facilitated search capabilities of GRIN; (iii) the development and definition of genetic materials needing registration (cultivars, germplasm, genetic stocks, parental lines, and mapping populations); and (iv) the recognition and allowance of IPR rights: the registration of crops is a healthy viable dynamic registration system to meet the needs of breeders over the next 80 yr

Challenges in the development of a widely applicable method for sugarcane (Saccharum spp.) shoot tip cryopreservation.

The USDA-ARS National Plant Germplasm System (NPGS) maintains 946 accessions of sugarcane (Saccharum spp.) in the field at the Subtropical Horticult sure Research Station in Miami, Florida. These accessions are particularly vulnerable to hurricanes, diseases and other threats. We sought to identify a method whereby clonally propagated sugarcane accessions could be successfully introduced into tissue culture, multiplied, and then cryopreserved as shoot tips for long-term preservation at he National Laboratory for Genetic Resources Preservation in For Collins, Colorado. For many accessions, 70% isopropyl alcohol and 20% commercial bleach treatments, followed by three rinses of sterile water weresufficient to remove microbial contaminants during the introduction process. However, in some cases, cefotaxime was particularly effective for removing bacterial contamination. We found that antioxidant treatments of glutathione, glycine betaine, and ascorbic acid did not improve regrowth after liquid nitrogen exposure usine either PVS2 or PVS3 as cryoprotectants in droplet vitrification cryopreservation methods. Exposure durations of PVS2 and PVS3 were optimized, with and without exposure to liquid nitrogen (LN), and shoot tip regrowth levels ranged from 0 to 37% after LN exposure. Published methods for encapsulation dehydration and V-plate vitrification cryopreservation procedures were tested to determine if acceptable results could be obtained. Using these methods, shoot tip regrowth levels ranged from 0 to 50% after LN exposure. We conclude that the sugarcane cryopreservation methods that we tested are not yet ready for implementation in the NPGS.Apresentado no Acta Horticulturae, 1234. DOI 10.17660/ActaHor