|AYNALEM, HAILU - OREGON STATE UNIV
Submitted to: International Association for Plant Tissue Culture & Biotechnology Congress
Publication Type: Proceedings
Publication Acceptance Date: 1/15/2002
Publication Date: N/A
Interpretive Summary: We wanted to see if tissue cultured shoots of Bermuda grass could survive cold storage. If so, tissue culture would be an efficient way to preserve Bermuda grass for conservation efforts. We evaluated a diverse group including seven species for storage at refrigerated temperatures. Shoot cultures were transferred to plastic tissue-culture bags, grown for 1 week, then cold acclimated in a growth chamber for 1 week before storage at refrigerator temperatures. Shoots evaluated after 4 months storage were all in excellent conditions with green color and some roots. From 6 to 12 months some accessions declined significantly while others showed little or no change. Cold-stored shoot cultures can provide backup storage for Bermudagrass germplasm, however the length of viable storage varies with the plant type and may range from 6 months to several years.
Technical Abstract: Genetic resources of vegetatively propagated plants are safeguarded by medium-term storage of micropropagated plants. These procedures provide cost effective backups for field or greenhouse germplasm collections. Cynodon (Bermudagrass) germplasm stored as growing plants provides a number of challenges to curators. In-vitro backup collections increase security for existing plant collections. We evaluated a diverse group of Cynodon species and selections for 4oC storage including: Cynodon barberi; C. dactylon vars. dactylon, elegans and polevansii; C. nlemfuensi var. robustus; C. radiantus; C. transvaalensis. Actively multiplying shoots were transferred to 5-cell tissue-culture bags of MS medium with no growth regulators, 2 bags per accession. Shoots were planted, sealed in bags grown in the growth room for 1 week (25o C, 16 hr photoperiod, 25 uM/m-2.s-1), cold acclimatized (8 hr 22o C day/16 hr -1oC night) for 1 week, then stored at 40C with a 12 hr photoperiod (10 uMm-2s-1). Cold-stored shoots were evaluated at 4 months, then at 8 months, 1 month by visual analysis. All accessions maintained their green color and produced roots during the first 4-month storage period. From 6 to 12 months some accessions declined significantly while others showed little or no change. Cold-stored shoot cultures can provide backup storage for Bermudagrass germplasm, however the length of viable storage is highly genotype dependent.