References

Over de houdbaarheid van snijbloemen. Medede-lingen Landbouwhogeschool Wageningen, 57 (9), 1-62. Aarts, J.F.T. (1957b). De ontwikkeling en houdbaarheid van afgesneden bloemen. Mededelingen van de Directeur van de Tuin-bouw, 20, 690-701. Aarts, J.F.T. (1962). The keepability of cut flowers. XVI International Horticultural Congress, Brussels, Vol. 5, 46-53. Ballantyne, D.J. (1965). Senescence of daffodil (Narcissus pseudonar-cissus L.) cut flowers treated with benzyladenine...

The possible mechanism of sporopollenin polymerisation

The hypothesised relatedness of sporopollenin with cutin, suberin and lignin would suggest that monomer polymerisation is also mediated via a common mechanism. However, the mode of cutin and suberin lignin polymerisation is different (Fig. 2). Cutin polymerisation is catalysed by a hydroxyacyl-CoA cutin transacylase, which transfers activated cutin monomers to the growing polymer (Kolattukudy, 1980 Kolattukudy & Espelie,1985). Although there is little direct evidence, it is envisaged that...

References Reproduction In Plants

Flower behaviour in Linum lewisii some ecological and physiological factors in opening and abscission of petals. American Midland Naturalist, 97, 321-32. Arditti, J., Hogan, N.M. & Chadwick, A.V. (1973). Post-pollination phenomena in orchid flowers. IV. Effects of ethylene. American Journal of Botany, 60, 883-8. Burdon, J.N. & Sexton, R. (1990). The role of ethylene in the shedding of red raspberry fruit. Annals of Botany, 66, 111-20. Burdon, J.N. & Sexton, R....

Longevity of flowers

The longevity of the flowers of many species has been reported by several authors. The time to wilting in the monocots Table 1 varies from less than 60 minutes after anthesis in the orchid Desmotrichum appendicula- Society for Experimental Biology Seminar Series 55 Molecular and Cellular Aspects of Plant Reproduction, ed. R.J. Scott amp A.D. Stead. Cambridge University Press, 1994, pp. 215 237. Table 1. Time to wilting in monocotyledonous flowers showing perianth wilting as the first sign of...

The sensitivity factor

Since tissue sensitivity to ethylene is an important factor in the control of flower senescence, an appreciation and understanding of the nature of the 'sensitivity factor' is central to our understanding of the mechanisms involved in the control of ethylene action. The involvement of ethylene in senescence varies greatly amongst the flowers of different species. Mature flowers of species such as carnation and petunia are sensitive to ethylene and exposure to ethylene will accelerate their...

Physiological and structural aspects of petal senescence

Amongst the species having very short-lived flowers there are examples where the flowers wilt or abscise. For example, in Linum perenne the petals abscise within a day of flower opening Wacker, 1911 whilst those of Ipomoea purpurea Matile amp Winkenbach, 1971 and Hemerocallis fulva Lukaszewski amp Reid, 1989 wilt within one day. a Flowers showing petal wilting The physiological mechanisms which control these processes are diverse Hemerocallis flowers, for example, are ethylene-insensitive...

Pollen mitosis I a key developmental switch during pollen formation

One of the most striking features of pollen development is the highly asymmetric mitotic division of the microspore, pollen mitosis I PMI , which results in the formation of two unequal cells, the vegetative and generative cells, which possess dramatically different structures and developmental fates. PMI by definition signifies the initiation of pollen development as opposed to microspore development and is a prerequisite for the correct maturation of the male gametophyte. Experimental...

Tapetumspecific promoter in tobacco

Having demonstrated the developmental pattern of A6 expression throughout floral development in B. napus, the next aim was to assay the A6 protein directly for glucanase activity. In addition to confirming the sequence data which suggests that A6 is a glucanase, assays could also allow exo- and endoglucanase activity to be distinguished. To this end, the entire coding region of the A. thaliana G62 genomic clone was linked to the A9 tapetum-specific promoter Paul et al., 1992 and transferred...