The heat-resistant — plants of deserts and dry habitats (succulents, some cactuses, the representatives of family of Tols-tyankova maintaining heating by sunshine to 50 — 65 "S. Zharoustoychivost of succulents in many respects the increased viscosity of cytoplasm and the content of water in cages lowered by a metabolism.
This conclusion in turn suggests an idea that yarovization is transmitted through some samoreplitsiruyu-shchissya cytoplasmatic organellas, but it is equally also possible that in the course of a yarovization there is an of certain genes, and the happened change is transferred on affiliated kernels during division.
Need of cooling for a zalozheniye of a flower cannot be mixed with need of cooling for removal of rest of kidneys. So, many wood plants blossom in the spring, but the flower zalozheniye in a kidney occurs during the last summer, and they need cooling not for a flower, and for removal of rest of a kidney.
Heat tolerance (heat resistance) — ability of to transfer action of high temperatures, an overheat. These are the caused sign. Types and grades of plants differ on endurance to high temperatures.
Not heat-resistant — mezofitny and water plants. Mezofita of open places transfer short-term action of temperatures 40 — 47 "With, the shaded places — about 40 — 42 °C, water plants maintain temperature increase to 38 — 42 °C. From the thermophilic plants of southern latitudes are most heat-resistant (a sorghum, rice, a cotton, a castor-bean tree, etc.).
With increase in the period of cooling the of effect is at a loss and at a full yarovization high temperatures have no impact. Deyarovizirovanny grains can be yarovizirovat the subsequent influence of a again.
Many plants needing cooling are similar to long-day plants that in a vegetative stage have rozetochny and show characteristic lengthening of tsvetonosny escape during blossoming.