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ARS Home » Pacific West Area » Corvallis, Oregon » National Clonal Germplasm Repository » Research » Publications at this Location » Publication #308199
Title: Increased CaCl2, MgS04 and KH2P04 improve the growth of micropropagated red raspberries

Author
item POOTHONG, SUKALYA - Oregon State University
item Reed, Barbara

Submitted to: In Vitro Cellular and Developmental Biology - Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2015
Publication Date: 10/21/2015
Citation: Poothong, S., Reed, B.M. 2015. Increased CaCl2, MgS04 and KH2P04 improve the growth of micropropagated red raspberries. In Vitro Cellular and Developmental Biology - Plants. 51:648–658. doi: 10.1007/s11627-015-9720-y.

Interpretive Summary: Red raspberries are difficult to successfully grow in tissue culture on standard growth medium. The most commonly used growth medium for commercial red raspberry cultivar micropropagation does not work well for many. Some display stunting, discoloration, callus, leaf spots or necrosis, and these disorders are likely caused by non-optimum concentrations of essential minerals. An initial study modeling mineral components concluded that three chemical (CaCl2, MgSO4 and KH2PO4) components significantly affected red raspberry quality and growth. Results varied by cultivar for some characteristics, but modeling indicated that all cultivars required much more of all three minerals for improved growth and quality compared to those found in the common medium. The optimal composition for improving overall quality and mineral status of the five cultivars was 2.5-3.0 times the original concentration of the three components.

Technical Abstract: The amount of genetic variation in red raspberries makes it difficult to successfully apply a standard in vitro growth medium to all cultivars and selections. Murashige and Skoog medium (MS) is commonly used for commercial red raspberry cultivar micropropagation. However, many cultivars grown on MS medium display stunting, hyperhydricity, discoloration, callus, leaf spots or necrosis, and these disorders are likely caused by non-optimum concentrations of essential minerals. An initial study modeling MS medium mineral components concluded that the mesos (CaCl2, MgSO4 and KH2PO4) components significantly affected red raspberry quality and growth. The present study investigated the effects of the individual mesos components and optimized the concentrations using a 3-dimensional experimental design based on response surface methodology. Five red raspberry cultivars were tested with 29 computer-selected treatments chosen from all possible combinations of five concentrations of each component. Shoot cultures were evaluated for quality, multiplication, shoot length, leaf characteristics and plant mineral content. High concentrations of CaCl2 and KH2PO4 significantly increased shoot length for most cultivars. Cultivars differed in their response for the number of shoots, leaf color and leaf size. Results varied by cultivar for some characteristics, but modeling indicated that all cultivars required significantly higher (p =0.05) concentrations of all three mesos components for improved growth and quality compared to those found in MS medium. The optimal mesos composition for improving overall quality and mineral status of the five cultivars was 2.5-3.0× the MS concentration of the three salts.