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Meadowfoam (L. alba) seeds are a source of long-chain fatty acids which are stable under diverse conditions. The fatty-acid composition makes this seed oil valuable for use in cosmetics, lubricants, rubber additives, and plastics. While a few meadowfoam cultivars have been developed, high-yielding germplasm is required for further crop improvement. The objective of this study was to evaluate potential seed production and associated morphological and phenological characteristics of 24 L. alba germplasm accessions maintained by the U.S. National Plant Germplasm System. The average seed yield varied from 39.3 to 221.3 g [plot.sup.-1] and was significantly different among years in this evaluation. The average number of seeds [floret.sup.-1] under pollination by naturally occurring insects was similar to the number of seeds developed without presence of pollinators. The number of days from sowing to first 10 and 50% bloom, as well as to the first and last seed maturity, varied significantly among years and accessions. Seed yield was positively correlated with 100-seed weight, the interval between first 10 and 50% bloom, and longest seed-bearing stem. The number of seeds [floret.sup.-1] was not significantly correlated with seed yield. Significant interaction between accessions and years was observed for number of seeds [floret.sup.-1] developed without insect pollinators, the interval between first 10 and 50% bloom, longest seed-bearing stem, number of days from sowing to first and last harvest, and harvest spread. Some germplasm accessions evaluated in this study had a higher seed yield than yields reported in the literature and exhibited advantageous characteristics applicable in meadowfoam improvement.

Short term gas exchange measurements and long term field trials have confirmed the several fold greater water to dry mailer conversion efficiency of cactus than C3 and C4 plants. The protein and dry matter digestibility of Opuntia typically are in the 60 to 70% range and are on par with other high quality forages. While the protein content is low (ca. 6%), as is usually observed in unfertilized rangeland, fertilization can increase the protein to 10 to 15%. The high mineral content (4.2% Ca and 2.3% K) would appear to be beneficial to lactating animals. The high water content, maintained in drought periods, is useful in meeting animal water requirements. In both Mexico and the USA spiny varieties have been utilized by burning offspines in the field with propane torches, or by use of stationary forage choppers at the dairy/ feedlot. Spineless varieties require intensive fencing for protection against wildlife and uncontrolled livestock. Spineless varieties generally have less tolerance to freezing weather than spiny varieties. It has been estimated that about 400 000 ha of spineless varieties have been planted in Brazil, from 700 000 to 1 000 000 ha in northern Africa and that cactus was an important forage component on 3 million ha of grazing lands in northern Mexico. The majority of the spiny and spineless types used worldwide for forage are preserved in the USDA NPGS germplasm collection. This paper reviews the environmental adaptability and most important nutritional characteristics of major forage clones. Spineless clones are described that are adaptable to USDA cold hardiness zones 7, 8, and 9.

An important method for plant germplasm conservation is offered by a biotechnology-based approach of cryopreservation. Cryopreservation refers to the storage of plant material at ultralow temperatures in liquid nitrogen. A procedure for cryopreservation of polyembryonic seeds was improved for selected citrus cultivars from Turkey. Seed dehydration was performed at different exposure times, in sterile conditions of a laminar flow-hood. The tested cultivars showed the highest tolerance to low temperature storage when the seeds were first dehydrated to a moisture content of 21.8% for Poncirus trifoliata Raf. x Citrus sinensis Osb. and to 17.6% for Citrus limonia Osbeck. The postcryopreservation germinability ranged from 73.3% (Poncirus trifoliata Raf. x C. sinensis Osb. and Fortunella margarita (Lour.) Swingle) to 93.3% (C. jambhiri Lush.). Dehydration was beneficial for germination of seeds from all of the tested citrus species after the liquid nitrogen exposure. Seedlings derived from cryopreserved seeds had well-formed shoots and roots and were easily acclimated to greenhouse conditions. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta) is the only commercial species of the Manihot genus, cultivated for its starchy tuber roots. However, cassava seeds are known to be rich in oils and fats, there are scant reports on the content and properties of oil from cassava seeds and its wild relatives. Wild Manihot species usually produce a higher number of seeds with a large diversity in shape and weight. Seeds of 106 accessions belonging to 12 species of Manihot from the collection of Embrapa Cassava and Fruits were evaluated for oil content by NMR and fatty acids composition by gas chromatography. The oil content ranged from 17.2% (M. caerulescens) to 30.7% (M. flabellifolia) and the species clustered into eight different groups based on the oil content. Five fatty acids were found in all species with the average content of the fatty acids being: linoleic (C18:2) 61.5%; oleic (C18:1) 20.0%; palmitic (C16:0) 12.3%; stearic (C18:0) 4.5%; and linolenic (C18:3) 1.7%. The content of fatty acids varied significantly between species as well as between accessions within a species. The highest content of linoleic acid was in seeds of M. peruviana, M. pseudoglaziovii, M. cecropiaefolia, M. flabellifolia, M. glaziovii and M. carthaginensis (average of 65%); and the highest level of oleic acid was in M. caerulescens, M. esculenta, M. anomala, M. dichotoma and M. tomentosa (average of 23%). The collection of Embrapa's Manihot germplasm is a valuable source for cassava breeding programs, containing a large variability in seed size, oil content and fatty acid composition. The oil from seeds of wild Manihot species may be equally valuable for industrial uses as oil from seeds of other Euphorbiaceae species. [ABSTRACT FROM AUTHOR]

Rubus L. species are pan-global in their distribution and used as food throughout the world. Their fruits, collectively called brambles, come in a variety of colors from black, through various shades of red and yellow to white. The USDA-ARS, National Plant Germplasm System maintains >2250 accession seed- and screenhouse-based Rubus collection in Corvallis, OR and the USDA-ARS, National Laboratory for Genetic Resources Preservation in Fort Collins, CO has cryopreserved and maintains 200 accessions in liquid nitrogen (LN). We investigated regrowth of 25 selected Rubus accessions cryopreserved by droplet vitrification and stored cryogenically for 15 to 20 years, to determine the need for possible repropagation and reprocessing. The initial regrowth of the stored accessions after 24 h in LN ranged from 50 to 100%. After long-term LN storage, overall regrowth was significantly lower than the initial regrowth (on the average for the 25 accessions by 8.7%). However, except for one accession with recovery of 23% (R. laciniatus PI 553651), the regrowth of the other 24 accessions ranged from 40 to 100%, with 16 accessions at >73% regrowth. High initial viability was important for recovering large numbers of living shoots after long-term storage. Extending regrowth of five accessions from six to 12 wk did not significantly increase the regrowth, suggesting that a six-wk cultivation is sufficient for regrowth assessment. Knowledge of changes in viability over time in cryopreserved collections is vital information for curators to determine what repropagation intervals are needed for specific germplasm collections. These studies also provide large-scale information on changes that might be needed in the cryopreservation protocol for the next storage cycle., Competing Interests: Declaration of Competing Interest None, (Copyright © 2024. Published by Elsevier Inc.)

The United States of America collection of mountain mint (Pycnanthemum Michx.) is held at the USDA-ARS National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon as seed, potted plants and tissue cultures and a long-term storage collection is preserved at the USDA-ARS National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, Colorado. The clonal collection is comprised of 34 accessions as potted plants that are duplicated with 31 accessions stored as in vitro cultures at 4 degrees C in tissue culture bags for medium-term storage at NCGR and as cryopreserved shoot tips in liquid nitrogen at NCGRP for long-term storage. This study reports on these two models of preservation of mountain mint at the U.S. National Plant Germplasm System. In vitro plants required 2 to 7 months for propagation on MS medium without growth regulators before storage at 4 degrees C. Plants remained in storage with good vigour in bags on 1/2x nitrogen MS medium without growth regulators for a mean of 2.08 y. An encapsulation-dehydration protocol was successful for cryopreservation of shoot tips from cold acclimated in vitro plants. Post-cryo viability, indicated by shoot tips with developed leaves and roots, ranged from 60 to 100 % for 27 accessions and 40 to 50 % for the other four. The encapsulation-dehydration cryopreservation method proved suitable for long-term preservation of the 31 Pycnanthemum accessions. These alternative storage forms allow for active use of the collection as well as base storage for clonally propagated accessions.