Q.What do you understand by Photoperiodism? Give its significance (any two).
You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.
Start your 14-day free trial to unlock the full solution →Photoperiodism is the response of plants to the relative length of light and dark periods (day length), which chiefly controls the induction of flowering; its significance lies in timing flowering to the right season and in allowing artificial control of crop flowering.
Meaning. Some plants require a particular duration of daily light (photoperiod) to shift from the vegetative to the flowering (reproductive) phase. This response of plants to the periods of day length (light) and night length (dark) is called photoperiodism. It was shown that it is actually the duration of the dark period (night) that is critical, and the site of perception of the light/dark stimulus is the leaves (through the pigment phytochrome), while flowering occurs at the shoot apex - implying that a hormonal signal (florigen) moves from leaf to bud.
Types of plants based on photoperiod:
- Short-day plants (SDP): flower when the day length is shorter than a critical period (i.e. long nights), e.g. Chrysanthemum, rice.
- Long-day plants (LDP): flower when the day length is longer than a critical period (short nights), e.g. wheat, spinach.
- Day-neutral plants (DNP): flowering is not affected by day length, e.g. tomato, cucumber.
Significance (any two): …
Unlock everything free for 14 days
- Full step-by-step solutions
- Concept-first explanations
- Methods, shortcuts & mistakes
- PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.