Changes During Early Seed and Axes Deterioration: I. Seed Quality and Mitochondrial Respiration
- J. M. Ferguson ,
- D. M. TeKrony and
- D. B. Egli
Understanding the cause of soybean [Glycine max (L.) Merr.] seed deterioration during storage will assist in the development of accurate laboratory tests to evaluate seed vigor. This study was designed to investigate the changes that occur in mitochondria! respiration during the early stages of soybean seed deterioration. High-quality seed lots of ‘Desoto’ and ‘Union’ soybean were stored at 25 °C and 115 g kg-1 seed moisture. Seed quality (germination and vigor) and conductivity of leachate from embryonic axes were measured at monthly intervals during storage. Mitochondrial State 3 (ST 3) respiration rates and respiratory control ratios (RCR) were measured from excised axes of samples after 24 h of imbibition. Germination remained high for seeds of both cultivars throughout storage; however, seed vigor (as measured by accelerated aging) declined significantly after 7 and 10 months for Union and Desoto, respectively. Conductivity of the leachate from excised axes for both cultivars increased early during storage prior to detectable changes in whole seed vigor. State 3 respiration rates of mitochondria from axes decreased throughout storage and RCR values declined after 2 months for Union and after 4 months for Desoto. Decreases in ST 3 respiration rates and RCR in both cultivars preceded measurable declines in whole-seed vigor and correlated with increases in the conductivity of axes leachate.
Copyright © 1990.