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ARS Home » Pacific West Area » Corvallis, Oregon » National Clonal Germplasm Repository » Research » Publications at this Location » Publication #176305
Title: A COMPARISON OF VISUAL AND IMAGE ANALYSIS FOR THE STORAGE OF MICROPROPAGATED PLANTS

Author
item AYNALEM, HAILU - OREGON STATE UNIVERSITY
item RIGHETTI, TIMOTHY - OREGON STATE UNIVERSITY
item Reed, Barbara

Submitted to: In Vitro Cellular and Developmental Biology - Plants
Publication Type: Abstract Only
Publication Acceptance Date: 1/12/2005
Publication Date: 1/12/2005
Citation: Aynalem, H.M., Righetti, T.L., Reed, B.M. 2005. A comparison of visual and image analysis for the storage of micropropagated plants [abstract]. In Vitro Cellular and Developmental Biology - Plants. 41:52A.

Interpretive Summary: The USDA-ARS National Clonal Germplasm Repository (NCGR) stores national collections of fruit, nut and specialty crops. The primary collections are maintained as growing plants fields or greenhouses. These plants could be lost from environmental stresses and insect or diseases. As a secondary back up a subset of the field collection was established as virus-free tissue cultures stored at refrigerator temperatures. Survival of these cultures in storage at refrigerator temperatures can vary from 6 months to 5 years depending on the plant type. Stored plants are evaluated at 4 month intervals to determine their health status. In this study we tested four cultivated pears to determine if computer anlysis of digital photographs would be more effective for determining health status than a visual evaluation. Correlations between digital and visual analysis were significant for some factors. While these tests do not provide a definitive evaluation technique, they will assist in the development of digital imaging as an alternative technique for evaluation of stored tissue culture plantlets.

Technical Abstract: In vitro plants in slow-growth storage require routine evaluation for assessment of viability and timing of repropagation. Determination of plantlet health by visual assessment is difficult due to variations in growth pattern and plant structure. Developing a standardized system of plant evaluation would improve the efficiency of in vitro storage. A study was initiated to develop digital-image analysis techniques for plantlets during slow-growth storage and to compare that system with visual examinations. Pear, Pyrus communis L., cultivars were chosen for study because they have an open structure and clear position of internodes for image composition. Pear shoots stored at 4°C in tissue culture bags were evaluated monthly by visual examination and by digital image analysis. Digital images were evaluated for red, green, blue, NDVI (normalized differences of vegetation index), green/red (G/R), hue, intensity, and saturation (HIS) at the first two nodes of each plantlet. Over the first 5 months the visual ratings declined steadily for P. communis 'Luscious' and 'Bartlett-Swiss' while 'Belle Lucrative' and 'Louise Bonne de Jersey' did not begin to decline until 9 months and then reached a plateau. Regression analysis indicated that the NDVI and G/R ratios changed significantly over the 15-month rating period for most cultivars. Correlations between visual ratings and G/R and NDVI values were significant (R2 ' 0.5) for 'Louise Bonne de Jersey', 'Luscious' and 'Bartlett-Swiss'. 'Belle Lucrative' visual ratings did not correlate with any color value data. These results will assist in the development of digital imaging as an alternative technique for evaluation of stored tissue culture plantlets.