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Comparison of the staining method with actual
pollen germination tests In order to determine the accuracy and reliability of the staining method, a pollen germination media was developed for actual germination tests. Correlation studies were then made between the two methods of determining pollen viability. The germination media is prepared in the following manner: One gram of agar and 30 gms. of cane sugar are added to 100 ml. of boiling distilled water. Mix constantly. After the sugar and agar are dissolved, 2 ppm of MnSO4 and 5 ppm of H3BO3 are added. The hot media is placed on deep depression slides and allowed to cool to a semi-solid form. Viable pollen dusted on the media and covered begins to germinate immediately. A protrusion is formed as the germ tube develops. Protrusions can be observed under the microscope at 450 x to determine the occurrence of protoplasmic streaming. Viable pollen is identified by the rapid protoplasmic streaming in the protrusion; non-viable pollen forms only very small protrusions with no protoplasmic streaming. There is no further development of the germ tube. Viable pollen grains, on the other hand, form relatively long germ tubes before the cell bursts. Most pollen grains burst soon after the germ tube begins to develop. Correlations were made using the two methods for determination of pollen viability, viz., actual germination by the agar method and staining by MTT. Samples of pollen grains from the same anther were tested for viability by the two methods. Twenty tests were conducted on pollen grain samples in which the viability ranged from nearly 0 to 100%. A highly significant correlation coefficient of 0.99 was calculated. It is concluded that the MTT staining method is both accurate and reliable in determining the viability of wheat pollen. Since the MTT staining method determines the number of viable pollen grains at the time of dusting on the media, this method can be used to determine wheat pollen longevity under varying environmental conditions. Literature Cited (I) ASLAM, M., M. S. BROWN, and R. J. KOHEL. 1964. Evaluation of seven tetrazolium salts as vital pollen stains in cotton, Gossypium hirsutum L. Crop Sci. 4 : 508-510. (2) HECKER, R. J. 1963. Use of tetrazolium salts in determining viability of sugar beet pollen. Amer. Soc. Sugar Beet Tech. 12(6) : 521-528. (3) NORTON, J. D. 1966. Testing of plum pollen viability with tetrazolium salts. Amer. Soc. Hort. Sci. Proc. 89 : 132-134. (4) OBERLE, G. D., and R. WATSON. 1953. The use of 2, 3, 5-triphenyl tetrazolium chloride in viability of fruit pollen. Amer. Soc. Hort. Sci. Proc. 61 : 299-303. (5) SMITH, F. E. 1951. Tetrazolium salt. Science 113 : 751-754. (Received Jan. 23, 1968) |
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