The studies that have shown a correlation between ATP content and vigor in seeds of several unrelated species (Ching and Danielson, 1972; Ching, 1973; Lunn and Madsen, 1981) have been confounded by others that have indicated that ATP levels are not good indicators of vigor (Styler et al., 1980; Mazor et al-, 1984).
Similarly, the fact that embryos that have been rendered nonviable by accelerated aging still have the capacity
to reduce tetrazolium salts may be taken to indicate that viability loss may occur without concomitant loss of dehydrogenase activity in (at least some of) the mitochondria.
While these observations are in keeping with our current findings (see above), it must also be emphasized that the internal seed-associated mycoflora will survive the seed itself and greatly confound biochemical and metabolic interpretation.
This underscores the necessity for multifaceted investigations on the same seed sample if results are to be interpreted
unequivocally.