Cucumber (Cucumis sativus L.) seed performance as influenced by ovary and ovule position

The performance of cucumber (Cucumis sativus L.) seeds in relation to ovary and ovule position was monitored during seed production. Seeds from three (first, seventh and tenth nodes) fruit positions and three (stylar, interme diate and peduncular) ovule positions were harvested serially during develo pment and characterized with physiological and cellular markers. Seed moist ure contents declined to 30% approx. 35 d after pollination (DAP) and remai ned constant thereafter. At 42 DAP the maximum dry weight was acquired in s eeds except those from peduncular segments, whose dry weight accumulation l agged behind. The onset of germinability and desiccation tolerance occurred before the attainment of maximum dry weight, whereas seed performance, as shown by laboratory germination and greenhouse emergence, was largely impro ved after the completion of seed development. Cell cycle activities (DNA pe r nucleus and beta -tubulin content) ceased by 28 DAP, whereas the degradat ion of seed chlorophyll continued during the entire maturation period. Seed s from the top fruit and from the peduncular fruit segments were delayed in reaching maximum quality compared with seeds from other positions, and thi s was correlated with a slower decline of chlorophyll fluorescence.