Pollen Viability under a Stress Condition

Abstract

RATIONALE: Experiments have suggested that pollen viability could be an indicator of air pollution. This testing could potentially replace the pesticides and heavy metals measurement currently performed to evaluate that parameter. The purpose of this exploratory study was to ascertain the efficacy of a stain to evaluate the viability of different pollen species under an artificial stress condition.METHODS: Timothy grass, short ragweed, and white oak pollen species were stored at 35oC for one month. Pollen viability was measured at time 0 and after 1, 5, 10, 20, and 30 days of storage using p-phenylenediamine to detect the presence of myeloperoxidase. A minimum of 150 pollen grains were examined by optical microscopy. Pollen grains were considered viable if they turned totally black. All samples were extracted at the end of the study. Bradford protein content was measured and qualitative protein profile was analyzed by SDS-PAGE.RESULTS: The discrimination between viable and non-viable pollen was efficient for oak and controversial for ragweed. The percents of viable Timothy grass, oak, and short ragweed pollen at time 0 were 93.1%, 58.8%, and 100%, respectively. The respective percents at the end of the study were 0.0%, 16.2%, and 18.3%. No substantial changes in total protein content and protein profile were observed at any testing time compared with the respective baseline levels.CONCLUSION: Myeloperoxidase staining could be a sensitive marker of pollen integrity for some species. This test could have potential applications in different areas. Additional experiments in the laboratory should be performed before initiating field experiments. RATIONALE: Experiments have suggested that pollen viability could be an indicator of air pollution. This testing could potentially replace the pesticides and heavy metals measurement currently performed to evaluate that parameter. The purpose of this exploratory study was to ascertain the efficacy of a stain to evaluate the viability of different pollen species under an artificial stress condition. METHODS: Timothy grass, short ragweed, and white oak pollen species were stored at 35oC for one month. Pollen viability was measured at time 0 and after 1, 5, 10, 20, and 30 days of storage using p-phenylenediamine to detect the presence of myeloperoxidase. A minimum of 150 pollen grains were examined by optical microscopy. Pollen grains were considered viable if they turned totally black. All samples were extracted at the end of the study. Bradford protein content was measured and qualitative protein profile was analyzed by SDS-PAGE. RESULTS: The discrimination between viable and non-viable pollen was efficient for oak and controversial for ragweed. The percents of viable Timothy grass, oak, and short ragweed pollen at time 0 were 93.1%, 58.8%, and 100%, respectively. The respective percents at the end of the study were 0.0%, 16.2%, and 18.3%. No substantial changes in total protein content and protein profile were observed at any testing time compared with the respective baseline levels. CONCLUSION: Myeloperoxidase staining could be a sensitive marker of pollen integrity for some species. This test could have potential applications in different areas. Additional experiments in the laboratory should be performed before initiating field experiments.