Plant Science Resource

Gibberelin on flowering                                               Flowering is a cascade reaction consisting of several steps.Flowering signal is first received by phytochrome in the leaf and transmitted from the leaf to shoot apex.Upon arrival of the flowering stimulus, the growth mode of the meristem is changed from vegetative to reproductive. The shoot apical meristem produces primordia of floral organs; sepals, petals, stamens and carpels. Among the naturally occurring growth hormones, Gibberelins can have a strong influence on flowering.It has been experimentally proved that gibberellin can substitute for the longday or cold requirement for flowering in many plants.                        Reknowned plant physiologist Lang(1960) first demonstrate that added gibberelin could substitute for the poper environmental condition in Hyocyamus niger ,which usually require a long day for flowering.The flower-inducing activity of exogenously applied gibberellins is also clear in

  Instruments for Aeroponics                          Aeroponics is defined by the International Society for Soilless Culture as “a system where roots are maintained in an environment saturated with fine drops (a mist or aerosol) of nutrient solution” . In other words, instead of planting crops directly into the soil or media or growing them in a nutrient rich liquid solution, aeroponics relies upon applying a fine mist of nutrients and water directly onto the roots themselves. The plant is typically suspended or supported in some manner and the roots allowed to grow freely in the air inside a closed chamber without contact with any substrate.                              In these containers roots can find the best condition regarding oxygenation and moisture. These conditions allow for better plant nutrition assimilation in a more balanced way, with consequential faster development of the cultivated plants .                                             An aeroponic system was

  1) What turgor pressure? In plant cells the pressure component arises from the force exerted out wardly against the cell wall by expanding protoplast is called Turgor pressure. 2) What are diffusion and diffusion pressure deficit? Diffusion   is the net movement of molecules or atoms from a region of high concentration(or high chemical potential) to a region of low concentration (or low chemical potential).This is also referred to as the movement of a substance down a concentration gradient.   The difference   in the diffusion pressure between a solution and its solvent is called diffusion pressure deficit   (DPD).It was coined by B.S Meyer in 1938.The DPD of a solution is always lesser than its pure solvent.   3) What is plasmolysis? Give an example. The shrinkage of protoplast of cells due to exosmosis when the cell is placed   in hypertonic solution is called plasmolysis.   When a living plant cell is placed in a sufficiently concentrated solution of a suitabl