GERMINABILITY OF SEEDS AS A FUNCTION OF THE MATERNAL ENVIRONMENT

Day length and hormonal treatment during storage of ripe fruits of Cucumis sativus (cucumber) strongly influence the capacity of seeds later removed from these fruits to germinate in darkness.

With Lycopersicum esculentum (tomato), a day neutral flowering plant, the day length in which the mother plant grows during the period of fruit ripening influences germination within the tissues of over-ripe fruits. The germination percentage of lettuce "seeds" placed on half strength tomato juice from fruits ripened in short days was 58%, but on similarly diluted juice from fruits ripened in long days it was only 8%. The difference in germination in petri dishes between seeds from 'long' and 'short' day plants was even greater when the ripening tomato fruits were covered with aluminium foil. Similar germination results were obtained when the fruits had been stored in different photoperiods. Interestingly enough, day-length during maturation also affected ethylene release by tomato fruits, even after a single photoperiod, and the influence lasted for a number of days until the fruits were fully ripe. Application of ethepon to the tomato fruits stored in different day length regimes also emphasises the role of the photoperiod in ethylene release in addition to its effect on seed germination.

It may be suggested that a change in day length causes changes in hormonal levels which can then affect seed germination.

Download Adobe Acrobat Reader (free software to read PDF files)