Relationship between Position on the Parent Plant and Dormancy Characteristics of Seeds of Three Cultivars of Celery (Apium graveolens)

Abstract

Germination and seedling emergence studies were made on seeds harvested from four different umbel positions of three cultivars of celery (Apium graveolens L.). Although heavier seeds were produced from primary umbels than from other umbels, these were less viable as measured by the germination percentage at I8°C in the light. However, germination of viable seeds from quaternary umbels was lower than that of seeds from primary umbels at 18°C in the dark when incubated with GA4, (2 × 10 −4M) and seed from secondary and tertiary umbels tended to be intermediate in response. All viable seeds germinated when N6‐benzyladenine (10−2M) was used in combination with GA4. Seeds from quaternary umbels of two of the cultivars had a lower high‐temperature limit for germination in the dark than did seeds from other umbels. In glasshouse experiments the emergence of viable ‘quaternary’ seeds of these cultivars was higher than that of ‘primary’ seeds. Under these conditions the time to 50% of the final emergence as determined after 42 days was similar for seeds from all umbel positions within each cultivar. In two varieties seedling weights were greater from seeds of primary as compared to quaternary umbels, and in general, the largest seedlings arose from the heaviest seeds and the smallest from the lightest seeds in all three cultivars.

Spatial and Developmental Variation in Seed Dormancy Characteristics in the Fire-responsive Species Anigozanthos manglesii(Haemodoraceae) from Western Australia

“…3C). Some studies of the germination responses of seeds along a maturation gradient within an in¯orescence have shown the same trend in several nonAustralian species (Datta et al, 1970;Gonza lez-Rabanal et al, 1994), whereas the reverse eect has been demonstrated for other species (Thomas et al, 1979;Thomas, 1996). There may be several reasons for these dierences in germination pattern.…”

“…As basipetal seeds are older, they may be slightly more after-ripened and may germinate at a higher level than acropetal seeds. Lower dormancy of basipetal seeds may also be the result of higher levels of nutrients and phytohormones (Thomas et al, 1979), as resources may be allocated preferentially to basipetal seeds. Decreasing germination from the base to apex of the in¯orescence was demonstrated in the response of A. manglesii seeds to smoke and heat.…”

“…Intra-population variation in seed germination of A. manglesii Germination of seeds from dierent positions on the in¯orescence is known to vary in celery (Thomas et al, 1979) (Thomas, 1996). In A. manglesii, the prolonged and sequential maturation of individual¯owers (a 6±8 week period) (Hopper, 1993) within the in¯orescence may also lead to variation in seed quality and/or seed dormancy states.…”

Effects of seed cryopreservation and priming on germination in several cultivars of

“…Celery seeds show low and gradual germination (Thomas, Biddington and O'Toole, 1979). This has great economic implications in horticulture and hence several techniques have been assayed to synchronize and reduce the time of germination.…”

Effect of Nitrogen Fertilizer and Fruit Positions on Fruit and Seed Yields of Okro (Abelmoschus Esculentus L. Moench)

“…For Northern Nigeria Majanbu et al, (1986), Ahmed and Tullock-Reid (1980) and FAO (1992) recommended 100 kg N/ha. Thomas et al (1979) stated that the position at which a carrot or celery seed is produced on the plant can markedly affect its size, germination characteristics and size of the ensuing seedling. In both species the lowest percentage seed germination and seedling emergence were obtained from seeds produced on primary umbels A similar result was also recorded in tomato by Dias et al (2006).…”