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, intermediate and peduncular) ovule positions were harvested serially during development and characterized with physiological and cellular markers. Seed moisture contents declined to 30% approx. 35 d after pollination (DAP) and remained constant thereafter. At 42 DAP the maximum dry weight was acquired in seeds except those from peduncular segments, whose dry weight accumulation lagged 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 improved after the completion of seed development. Cell cycle activities (DNA per nucleus and beta -tubulin content) ceased by 28 DAP, whereas the degradation of seed chlorophyll continued during the entire maturation period. Seeds from the top fruit and from the peduncular fruit segments were delayed in reaching maximum quality compared with seeds from other positions, and this was correlated with a slower decline of chlorophyll fluorescence.