Photoperiod affects reproduction in seasonal breeders in both plants and animals why
Photoperiod affects reproductio in seasonal breeders, both plants and animals. In animals photoperiod affects the seasonal breeder through changes in melatonin secretion by the pineal gland. The reproductive axis is controlled by melatonin which is secreted at night only and therefore relays day length to the body. Photoperiod also affects testis size which ultimately causes causes gonad regression. Animals generally reproduce during spring and summer to take advantage of the warmer temperatures.
In plants photoperiod directly affects flowering by regulating the secretion of florigen and vernalin. Plants flower in response to the relative lengths of day and night. Plants produce pollen when pollinators will be active and help in transfer of pollens.