BGN 9: Techniques for rapid measurement of elongated coleoptile lengths in barley BARLEY GENETICS NEWSLETTER, VOL. 9, III. GENETIC AND CYTOLOGICAL TECHNIQUES
Ries pp. 113-114

III. 1. Techniques for rapid measurement of elongated coleoptile lengths in barley.

M.N. Ries, Margaret Patten Scoles, and R.T. Ramage. Department of Plant Sciences, University of Arizona, Tucson, Arizona 85721 U.S.A. "R"

In our studies of coleoptile length, techniques for accurate, rapid and repeatable measurement of individual coleoptile lengths are needed. We are using two techniques that satisfactorily meet our requirements. These techniques are also being used in studies where different nutrient or chemical solutions are absorbed by the growing seedlings.

Jones and Cobb (1963) reported a technique for laboratory germination testing that involved inclined substrate planes covered with moist thin cellulose tissue. They named their method the Laliberte or Cobb-Jones method. Their technique was designed to increase the speed of germination of small seed. An analogous technique was used by Ries (1977) to measure coleoptile lengths in barley. The technique reported by Ries (1977) was one developed by R. F. Eslick, Montana State University, Bozeman, Montana.

The technique of Eslick-Ries, as we use it, consists of positioning seed, embryo end down, with the seed apex at the top edge of a 4 x 15 cm strip of moist blotter paper. A second moistened blotter strip, of the same dimensions as the first, is gently positioned over the seed. The second blotter strip is firmly pressed around each seed. Blotters with seed in position are fastened with aluminum clips or staples at both ends and along the bottom. The secured blotters, with the seed at the top, are placed vertically into slotted plastic racks. The racks are placed in trays of distilled water, submerging the bottom edge of the blotters (Figure 1). The apparatus is then placed in the designated environment for the specific experiment.

Measurement of each coleoptile is fast and simple when the blotters with the elongated coleoptiles are removed from the rack and aligned on a plastic-covered sheet of milimeter graph paper scaled in 50 mm units (Figure 2).

Figure 1. Assembling blotters with seeds for placement in rack.
Figure 2. Growth pouch containing blotter and seedlings, placed on graph paper for measurement of coleoptiles.

We have modified the Eslick-Ries technique by inserting the strips moist blotter paper, with the seed in position, into the top fold of a Scientific Products diSPo Seed-Pak growth pouch. Pouches are held in a vertical position by holes punched in each side margin near the top of the pouch. The pouches are suspended by the holes on two small rods held in a frame of appropriate dimensions. This method requiresconsiderably less space in the germination chamber. It also results in increased germination percentages. There is less mess involved when measuring because the blotters are enclosed in the growth pouch.

We have found both techniques satisfactory tor coleoptile measurements. We are also using both techniques fcr experiments where different nutrient or chemical solutions are absorbed by growing seedlings.

References:

Jones, L.G. and R.D. Cobb, 1963. A technique for increasing the speed of laboratory germination testing. Proc. Assoc. Off. Seed Anal. 53:144-160.

Ries, M.N. 1977. Differences in seedling emergence, plant morphology, soil moisture removal by cropping, yield and quality components and allelism of several Betzes barley (Hordeum vulgare L.) "brachytic" isotypes. M. S. Thesis. Montana State University, Bozeman, Montana.

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