Author
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Reed, Barbara |
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Submitted to: In Vitro Cellular and Developmental Biology - Plants
Publication Type: Abstract Only Publication Acceptance Date: 5/20/2007 Publication Date: 5/20/2007 Citation: Reed, B.M. 2007. Culture and Storage Medium Iron Concentration Influence In-Vitro Cold Storage Duration of Hops (Humulus). In Vitro Cellular and Developmental Biology - Plants. 43:529-530. Interpretive Summary: The United States Department of Agriculture, Agricultural Research Service National Clonal Germplasm Repository (NCGR) at Corvallis, Oregon, preserves the global diversity of hops for the US Plant Germplasm System. To insure the safety of the collection, a part of the field collection was established as virus-free tissue culture plantlets stored in the refrigerator. Earlier studies showed that the type of iron used in the storage medium affected the length of time that plantletss could be cold stored. In this study four types of hops were first cultured on growth medium with either standard iron or standard iron with sequestrene iron for 3 weeks before storage. Plants were stored in tissue culture bags on standard iron at up to 5 X the normal concentration or on the combination of standard iron at 1X with sequestrene 138 iron. Initially the pretreatment medium produced no significant differences in plant condition ratings; however by 6 mo plantlets grown on standard iron had significantly higher ratings than those on sequestrene iron. At 8 mo of storage the plants on storage medium with lower iron concentration (0-1X) had higher ratings than did those on the high iron concentrations (2-5 X and sequestrene). Cultivar Vojvodina declined quickly in storage while 'Cascade' and 'USDA 21119' grew poorly with higher iron concentrations (>1X). 'Alpha Aroma' had much better ratings with iron in the medium (>0), and ratings were similar for all the iron concentrations (0.5-5 X or sequestrene). The overall results indicate that each of these hops should be grown on standard iron and stored on 0.5 or 1X standard iron medium for the longest duration in cold storage. Technical Abstract: The United States Department of Agriculture, Agricultural Research Service National Clonal Germplasm Repository (NCGR) at Corvallis, Oregon, preserves the global diversity of Humulus for the US Plant Germplasm System. To insure the safety of the collection, a subset of the field collection was established as virus-free in vitro cultures stored at 4 °C. Earlier studies showed that the iron formulation used in the storage medium affected storage duration. In this study four hop (Humulus lupulus L.) accessions were first cultured on MS medium with either standard MS iron or MS iron with 100 mg/L sequestrene iron 138 for 3 weeks before storage. Plants were stored in tissue culture bags on MS iron at 0, 0.5, 1, 2, 3, 4, and 5 X the normal concentration or on MS iron at 1X with 100 mg/L sequestrene 138 iron. There was a significant interaction of accession, pretreatment, and storage medium but not for pretreatment x storage medium. Initially the pretreatment medium produced no significant differences in plant condition ratings; however by 6 mo plantlets grown on 1X MS iron had significantly higher ratings than those on sequestrene iron. At 8 mo of storage the plants on storage medium with lower iron concentration (0-1X) had significantly higher ratings than did those on the high iron concentrations (2-5 X and sequestrene). Cultivar Vojvodina (Hum 155.003) declined quickly in storage while 'Cascade' (196.002) and 'USDA 21119' (410.002) showed significantly lower ratings with higher iron concentrations (>1X). 'Alpha Aroma' (627.002) had significantly better ratings with iron in the medium (>0), and there were no significant differences in ratings among the iron concentrations (0.5-5 X or sequestrene). The overall results indicate that each of these accessions should be grown on MS 1X iron and stored on MS 0.5 or 1X iron medium for the longest duration in cold storage. |
