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Room temperature phosporescence as a marker of seed qualityтезисы доклада
- Авторы: Veselova T.V., Veselovsky V.A., Kozar V.I.
- Сборник: International Workshop on Applied Seed Biology “New Development in seed Quality Improvement
- Тезисы
- Год издания: 2003
- Место издания: Lodz, Poland
- Первая страница: 57
- Последняя страница: 58
- Аннотация: The time, during which seeds maintain their viability (average lifetime) depends on their genotype and storage conditions (temperature, moisture content, oxygen content in air, etc.). To monitor seed condition and estimate the optimum storage length, seed viability is routinely tested by measuring their germinability and vigour. However, each seed can germinate only once. Therefore, this method prohibits any procedures for determination when an individual non-germinated seeds had died, and how long an individual seed would remain alive, if it was not permitted to germinate. Investigation of the morphological, physiological and biochemical processes responsible for seed deterioration allows one to predict the average lifetime of the seeds. Thus, none of the methods can monitor the quality state of each individual seed during storage. Room temperature phosphorescence (RTP) of air-dry seeds can help in the studying of seed deterioration during their storage. This conclusion is based on the relation between RTP intensity of air-dry seeds and their germination percentage, and on the possibility of fast and repeated non-destructive measurements of RTP intensity. RTP is known to decrease with increasing seed moisture content (coefficient correlation –0.94-0.98). The method provides for detecting a change in seed moisture content of 0.1-0.2% within 4-20% range. RTP method is very sensitive and it allows RTP measuring from individual seeds as well as from seed lots. Therefore we constructed the distribution of seeds by RTP level (moisture content). Seed lot with 97-100% germinability shows a normal distribution by RTP at low average level of RTP. The distribution of seed lot with 0% germinability has a single maximum too. It is markedly shifted to high RTP levels, because after losing water, dead seeds acquire a much higher capacity to emit RTP. The distribution of seed lot with low germinability may have two or three maxima (fractions or sub-lots). The fraction I (low RTP level) is represented by viable seeds with high vigour. The fraction III (high RTP level) involved dead seeds. The fraction II (intermediate RTP level) involved viable seeds with a lowered vigour. Seeds of second fraction either produced abnormal seedlings with disturbed growth due to impaired cell division, or did not protruded because radicle of embryo axis could not protrude the seed coat. The seeds of fraction I lose the capacity to germinate more slowly with time (during accelerated ageing as well as during natural ageing) than the seeds of fraction II. RTP registration of air-dry seeds makes it possible to evaluate their quality, seed lot heterogeneity and predict seed storage capacity. A measure of improving action of various external factors can be evaluated by RTP of air-dry seeds from an increase in fraction I seed number and decrease in fraction II seed number. Literature: Veselova T.V. et al., 1999. What are the implications in the heterogeneity of a seed population upon accelerated aging? Russ. J. Plant Physiol. 46, No 3, 477-483. Veselova T.V. 2002. Assessment of individual seed vigor and seed lot heterogeneity by room temperature phosphorescence. Seed Sci. & Technol. 30, No 1. 187-196.
- Добавил в систему: Веселова Татьяна Владимировна