a flowering Induction. Quantitative distinctions in flowering

you are: a flowering Induction

At some plants sensitive by the photoperiod, reaction to length of night not interrupted with light represents a type phenomenon ' all or anything '. Without appropriate inducing temnovyh the periods such plants remain in a vegetative condition vaguely long. at korotkodnevnogo plants durnishnika for an induction of some reproductive activity enough one long period of darkness though bolshee the number of photoinductive cycles can give more vigorous reaction of flowering (fig. 12.15). Other plants of short day, such as a soya, require for initsiatsii flowerings approximately four consecutive photoinductive cycles, and some kinds - even in bolshem their number.

At other plants reaction to the photoperiod can be quantitative, instead of qualitative. Such plants can blossom both at long, and at a short bottom, but at the certain photoperiods form better developed tsvetki or bolshee number tsvetkov. At other variant of quantitative reaction - at a Christmas cactus and of some others korotkodnevnyh plants - zatsvetanie accelerate low temperatures (in a combination to long night or as its replacement). The certain sequence of the photoperiods - approach of long days after short (clover) or on the contrary (many kinds Bryophyllum) is necessary to some plants. The Such mechanism allows a plant to perceive distinctions between lengthening of day in the spring and its shortening in the autumn. it is obvious, various reactions to the complex photoperiodic and temperature modes which are giving the chance to plants to adapt for special ecological niches were developed.