Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Plant Science

First Advisor

Charles L. Lay


Limitations on seed yield of flax (Linum usitatissimum L.) are a major concern of re searchers trying to develop higher yielding oilseed cultivars (37, 71). Dybing (37) stated that comparative studies of physiological and biochemical factors could provide necessary insight into the cause of these limitations. Based on repeated observations and yield trials of lines from the world collection, CI 2522 ('Linott') and CI 1194 (Grant) were selected as an "appropriate" pair for such studies (37). The basic criteria of selection of these two cultivars were a consistent difference in seed yield cross environments tested and similarities in such categories as disease resistance, agronomic type, morphology, flowering habit, fruiting habit, and flowering date (37).

During yield trials, Linott was consistently higher yielding than Grant. Although Grant expresses susceptibility to a North American race of rust (Melanpsora lini) and Linott does not, this factor was not responsible for the yield differences observed during the yield trials (37). Yield components data have indicated that the greater yield capacity of Linott stems from its ability to maintain more sinks, either as seeds per boll or bolls per area, than Grant (71). Comparison of Linott and Grant for total dry weight, period of main boll production (71), and net CO2 exchange rate (37) failed to show any differences that would explain the different yield potentials. Seed production in flax is very sensitive to environment al factors such as temperature and soil moisture level (42). Yet the crop is grown in areas of medium to low rainfall. Therefore, it was decided that ffurther comparative studies in Linott and Grant should include water relations. Stomatal characteristics, stomatal resistance, and osmotic potential were chosen as the areas that would be studied to determine if differences exist that could help to explain the difference in yield potential of Linott and Grant.

Library of Congress Subject Headings

Plants, Motion of fluids in.



Number of Pages



South Dakota State University