Germination of trifoliate orange seed in relation to fruit development, storage and drying

Summary

Seeds extracted from trifoliate orange fruit at differing stages of development required storage at 4.5°C for about 12 weeks before achieving the fastest rates and shortest time spans of germination. Seeds from ‘yellow-ripe’ fruit germinated less well than seeds from ‘overripe’ fruit. Seeds were stored for a further 34 weeks without any deterioration and for over 3 years with only slight loss of viability. The average dry weight per seed increased from 93 to 145 mg and the water concentration decreased from 129% to about 66% dry weight during fruit maturation. Water uptake during germination was independent of fruit maturity or time in storage, being about 10-15%. There was little effect of storage for up to 17 weeks on the germination of Cleopatra mandarin seeds, but germination was reduced and completely prevented by the loss of about 17% and 47% respectively of the water originally present. This appeared to be due to direct effects on the embryo rather than to changes in the permeability of the seed coat.