Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



Selection for high levels of freeze resistance in winter barley (Hordeum vulgare L.) has resulted in development of cultivars which: 1) contain low RNase I activity in young shoot tissue and 2) a single RNase activity band in expanding leaf tissue at Rf 0.08. By contrast, seedlings of less-hardy cultivars typically have; 1) two RNase polymorphs (Rf=0.54 and 0.58) in young shoot tissue and 2) fours polymorphs (Rf-054, 0.58, 0.64 and 0.81) in expanding leaf samples. All enzymes migrate toward the anode (ph 7.9) and only the fastest moving band is common to expanded leaves in both groups of plants. Enzyme activity comparisons were made in the presence of EDTA. A technique is described which requires minimal preparation of tissue extracts for electrophoresis on 3 mm diameter x55 mm length acrylamide gels. RNase assays on leaf samples as small as 30 mg fresh weight can be made. The technique is capable of rapidly determining the number of RNase polymorphs within a population and also detects variation in levels of activity of component enzymes. It appears to be an adequate procedure of studying inheritance of RNase in barley leaf tissue.

Library of Congress Subject Headings

Barley -- Genetics



Number of Pages



South Dakota State University