Flower Bud Atrophy in Baccara Roses

Abstract

Changes in gibberellin content and of the production of ethylene in the two upper shoots of roses were measured as affected by decreasing temperature and light intensity, factors which encourage flower atrophy. Decreases in temperature or light intensity to the whole plant reduce the endogenous content of gibberellin in the leaves of the two shoots. The decrease is more rapid and occurs earlier in leaves of the second shoot from the top, where "blindness" is more common. There was also a drop in the gibberellin content, when individual shoots were shaded, although the decrease was more moderate. A lowered light intensity reduced the production of endogenous ethylene by the two shoots, but in the second shoot this production increased after a number of days, before atrophy of the flower bud took place. It is suggested that gibberellin participates in the endogenous control of rose flower development, and the possibility is discussed that it acts by directing the translocation of metabolites to the flower bud.

Relationship between gibberellin and cytokinin activity and flowering in Rosa damascena Mill.

“…In Baccara roses it has been demonstrated that the content of GA-like substances was high in the leaves of flowering shoots as compared to abortive shoots [7,9,191. When GA3 was applied to Baccara roses it reduced the atrophy of flowers while kinetin applied to the apex did not affect flowering [19]. However, BA promoted growth and flowering of lateral shoots [7], reduced the incidence of flower bud abortion and enhanced sink strength [8].…”

“…Therefore the effect of GA3 and kinetin on flower yield was investigated. In some species of Rosa differences in plant hormones have been reported between flowering and nonflowering plants [19] but such studies have not been conducted with Rosa damascena. In this study, levels of GA and cytokinin-like substances in flowering and non-flowering plants and hormone changes associated with GA3 and kinetin treatment were measured in an attempt to illucidate the mechanisms of these bioregulators on growth and development of the plant.…”

Effect of Harvesting at Different Heights on Growth and Flower Yield of Carnation (Dianthus caryophyllus L.) in Second Season Crop

“…Severe pruning where most of the photosynthetic area was removed resulted in decreased number of flowers per plant. This could be a result of high respiration rate and loss of food reserves in the plant, finally flower yield reduced in severely pruned plants [20].…”

Relationship between Respiratory Change and Temperature on Flower Bud Blasting in Cymbidium

“…Some workers ascribe it to hormone imbalance and/or carbohydrate shortage (Mae and Vonk, 1974;Mastalerz, 1965;Moe, 1971;Vonk and Ribot, 1982;Zieslin and Halevy, 1976 (Fig. 1).…”