Study of geotropism versus hydrotropism in green bean radicles (Vigna radiata L.) by Oblique Olfactometer method

Plants respond to external stimuli which often involve constant movement of the plant. The movement of plant organs in response to external stimuli is responsible for the production of energy sources. Research on the nature of the radicle tropics aims to find out whether the roots actually grow downwards due to geotropism or hydrotropism. The mung bean species (Vigna radiata L.) is used because the germination process of this species does not require a long time and the seeds of this species are suitable for growing on olfactometer planting media and are suitable for growing in the climatic and geographical conditions in Indonesia. The method chosen in this research is the tilted olfactometer method, which is a planting method carried out using an aquarium hose and olfactometer connector which is tilted 30 degrees because this research aims to see the direction of growth of the radicles of mung beans (Vigna radiata L.) so this method was chosen; because the seeds can be positioned in the three-pronged olfactometer at an angle so that the final growth results can be distinguished between the tendency of the geotropism factor or the hydrotropism factor. It is proved that radicles tips would growth upward to wet cotton, against the geotropic effect.