Name the effect in which there is an immediate effect of one plant's pollen on the endosperm of a different plant's seed.

Correct option is A

The correct answer is (A) Xenia effect

Explanation:
• Xenia refers to the immediate influence of pollen genotype on the characteristics of the developing endosperm and sometimes the embryo of the seed in the same generation.
• Normally, pollen contributes genetically to the next generation, but in xenia, visible effects appear directly in the seed tissues such as color, size, or composition.
• This phenomenon is common in crops like maize, where kernel color or sweetness may change depending on the pollen source.
• The effect occurs because the endosperm is triploid and receives genetic material from both the male and female parents during double fertilization.
• As a result, pollen genes express immediately rather than waiting for the next generation.

Information Booster:
• First described in maize breeding experiments.
• Important in hybrid seed production and crop improvement.
• Helps breeders identify pollen influence quickly without waiting for progeny testing.
• A related term, metaxenia, refers to pollen effects on maternal tissues like fruit pulp.

Additional Knowledge:
• Xerophytic effect (Option B): Relates to plant adaptations to dry environments and is unrelated to pollen influence.
• Transpiration effect (Option C): Concerns water loss through stomata and has no connection with seed genetics.
• Photosynthetic effect (Option D): Deals with carbohydrate synthesis in chloroplasts and does not involve fertilization processes.
• Therefore, only xenia correctly describes the immediate genetic impact of pollen on endosperm traits.
• Understanding xenia is important in plant breeding, genetics, and seed technology because it explains rapid trait expression and assists in developing improved hybrids. Farmers and scientists use this knowledge to enhance yield, quality, and uniformity of crops. The concept highlights the significance of double fertilization in angiosperms and demonstrates how male gametes can influence seed characteristics directly, making the xenia effect a classic and frequently tested principle in plant science examinations.