a flowering Induction. Distribution and preservation of the factor causing flowering

you are: a flowering Induction

The Bodies perceiving the photoperiod, and the bodies reacting to it, at plants are often separate. As an example can serve korotkodnevnoe a plant durnishnik which blossoms if continuous temnovoj the period lasts more than 9 ch. We will assume that we create for any part of a plant of a condition of short day, placing it in the lightproof container while other plant is in conditions of long day. If there was no effect of transfer, it would be possible to expect that the site existing at a short bottom will blossom. However actually tsvetki are formed of all kidneys, even what were in conditions of long day. It is obvious that any signal is transferred from one part of a plant in another.

This experience can be made even more demonstrative, placing in the dark container only the one and only sheet so all other plant will be in conditions of long day; tsvetki and in this case are formed on all plant (fig. 12.16). It means that the sheet serves as body photoperiodic retseptsii and can influence the kidneys removed on some distance. Such influence almost is for certain caused by transfer of any substance formed in small amounts in photoinduced sheet.

This substance-hypothetical a hormone of flowering of plants - has been named florigenom. Florigen yet it was not possible to allocate and chemically to identify, but in its existence specify various experiments. If the plant And is induced to flowering, and - is not present, flowering could be caused by its inoculation on And (fig. 12.17). Such action can render even one imparted sheet. Similar experience is possible even in the event that And - korotkodnevnoe a plant, and B-dlinnodnevnoe. Thus, florigeny should be identical or at least functionally equivalent in plants of both types. Using a method koltsevanija steam killing cages floemy and blocking movement florigena, it is possible to show that the stream of hormones from privoja to a stock goes, probably, on live cages, it is probable on floeme, approximately with the same speed from what the great bulk of organic substances is transported.

Influence gibberellinom on dlinnodnevnye plants in the conditions of short day usually causes (though and not in all cases) an exit in an arrow which flowering (fig. 12.18 often follows).

To Similarly it we have now data that abstsizovaja acid promotes zatsvetaniju some korotkodnevnyh plants whereas auksin, stimulating formation etilena, can cause the same reaction at bromelievyh, for example in pineapple. Thus, florigen can and not to be any one substance; various hormones, nutrients or their suitable combinations, capable to cause flowering at certain plants in certain conditions can play its role.

One of the surprising facts, concerning a flowering induction, is that it at some plants can be prolonged beyond all bounds, even in case of return by the adverse photoperiod. Then the induced plant can be a source of stimulus for flowering - its donor in experiences with an inoculation - much longer of time of an initial induction. The stocks induced by an inoculation, can be donors florigena for other plants, even after branch from the primary donor. Thus, transition from vegetation to reproduction, apparently, is connected from any sort by the proof metabolic transformation conducting to long (and, perhaps, vaguely long) to formation of the factor causing flowering. Some authors came out with the assumption that is latent samoreplitsirujushchijsja the factor probably similar to an inactive virus which passes in the active form at the corresponding photoperiod. In this case initsiatsiju flowerings could be compared to infection with the illness extending from one individual to another until business will not come to an end spontaneous recover of the owner. For example, at korotkodnevnogo plants Perilla the minimum induction leads in the beginning to flowering, but then at the adverse photoperiod there is a gradual return to vegetative growth - the plant as though spontaneously recovers from ' illnesses ' flowerings. The question on the nature florigena and a flowering induction remains intriguing secret.