The phytochrome was discovered by

Given below are two statements.
Statement $I$: If the long dark period is interrupted by a brief flash of light,short day plants will not flower.
Statement $II$: When the long dark period is interrupted by a brief flash of light,long day plants can flower.
In the light of above statements,choose the most appropriate answer from the options given below:

The pigment phytochrome is involved in:

In short day plants $(SDP)$,flowering is induced by

Vernalisation can be reversed by

The phenomenon where flowering is dependent on exposure to low temperatures is known as: