Which among the following is Photoblastic Seed?

Correct option is D

Photoblastic seeds are those that require light to germinate. These seeds will not germinate if they are buried too deeply in the soil or if they are in complete darkness.
Examine each option:
(a) Rice (Oryza sativa)
· Rice seeds are generally not photoblastic. They can germinate in both light and dark conditions as long as other environmental conditions (like temperature and moisture) are met.
(b) Cucumber (Cucumis sativus)
· Cucumber seeds are also not typically photoblastic. They can germinate in the dark as well, provided they have the necessary warmth and moisture.
(c) Gram (Cicer arietinum)
· Gram, or chickpea seeds, are not photoblastic. They can germinate in dark conditions, with appropriate moisture and temperature.
(d) Lettuce (Lactuca sativa)
· Lettuce seeds are positively photoblastic, meaning they require light to germinate. This characteristic is why lettuce seeds are often sown very shallowly or even just pressed into the soil surface without covering.
(e) Wheat (Triticum aestivum)
· Wheat seeds are generally not photoblastic. They can germinate in both light and dark conditions if moisture and temperature are adequate.
Conclusion:
Lettuce is the correct answer because its seeds require light for germination, making it a photoblastic seed. The other seeds listed (Rice, Cucumber, Gram, and Wheat) do not have this requirement and can germinate in the absence of light.