Floral induction

In many fruit trees, especially apple, pear, and peach, the the extent of floral induction is increased by spraying them with inhibitors such as succinic acid-2,2-dimethyl hydrazine (sold by Uniroyal as Alar) and 2,3,5-triiodobenzoic acid. 

Pharis RP, Evans LT, King RW, Mander LN (1989) In Lord E, Bernier G (eds) Plant reproduction from floral induction to pollination. Am Soc Plant Physiol Symp Ser 1 29... 

Beever JE, Woolhouse HW (1973) Increased cytokinin from root system of Perilla and flower and fruit development. Nature 246 31-32 Beever JE, Woolhouse HW (1974) Increased eytokinin export from the roots of Perilla frutescens following disbudding or floral induction. In Bieleski RL, Ferguson AR, Cresswell MM (eds) Mechanism of regulation of plant growth. Roy Soc N Z, Wellington, pp 681-686... 

Light has a direct effect on floral induction. Grape cultivar fertility depends greatly on bud light exposure during this induction period. 

Bernier, G. Cellular and molecular aspects of floral induction. Longman, London 1970. 

Previous biosynthetic information indicates that following floral induction, squalene-oxide (SO), the common precursor of sterols and PT, is shunted into PT pathways effectively decreasing the availability of SO for sterol production. These data, along with kinetic studies with t2- H]acetate (viz. 4, 6, 9, 24, 48 hr feeds to leaf blades of 66 day plants) indicated that 24-alkyl sterols were synthesized at a low rate (data not shown). The results of the [2- H] and (24- H)lanosterol and [2-3H]cycloartenol feeds (Table 1) would indicate that... 

Since the level of cholesterol was highest in the vegetative apices before their transition to flowering (Table 1), and cholesterol levels actually decreased during floral differentiation, it is also possible that cholesterol is in some way associated with the process of floral initiation. For instance, there is some evidence in the literature that the flower-inducing hormone may be an isopentenoid or steroid-like compound Various steroids occur in plants, and cholesterol has been shown to be a key intermediate in their biosynthesis Ojll. Thus, it is possible that cholesterol was being used to make steroids, which may be involved in floral induction. 

Karege, E., Penel, C., and Greppin, H., 1982, Floral induction in spinach leaves by light, temperature and gibberellic acid Use of the photocontrol of the basic peroxidase activity as a biochemical marker, Z. Pflanzenphysiol., 107 357-365. 

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