Question

Haploids can be artificially produced by -
A. Colchicine doubling
B. X-ray treatment
C. Pollen culture
D. Distant hybridization
E. Infrared radiation
Choose the correct answer from the options given below :

• A. A, B, and C Only
• B. B, C, and E Only
• C. A, D, and E Only
• D. B, C, and D Only

Hint:

The two most important methods for haploid production are anther/pollen culture (androgenesis) and ovary/ovule culture (gynogenesis). Distant hybridization leading to chromosome elimination is another key method, especially in cereals.

Answer 1

The Correct Option is D

Step 1: Concept Overview:
The question requires identifying valid methods for artificial haploid plant production.
Step 2: Detailed Analysis:
A. Colchicine doubling: Colchicine duplicates chromosome numbers, converting haploids to homozygous diploids, not producing haploids. (Incorrect)
B. X-ray treatment: X-ray irradiation of pollen can destroy male gamete genetic material. Subsequent pollination can induce parthenogenetic development of the egg cell into a haploid embryo, a valid but uncommon method. (Correct)
C. Pollen culture: Also known as anther/microspore culture, this widely used technique involves in vitro culture of immature pollen grains (microspores) to develop haploid plants (androgenesis). (Correct)
D. Distant hybridization: Crossing distantly related species (e.g., wheat with maize, or barley with Hordeum bulbosum) can result in selective elimination of one parent's chromosomes during early embryo development, producing a haploid plant from the other parent. (Correct)
E. Infrared radiation: Infrared radiation, associated with heat, is not used to induce haploidy. (Incorrect)
Step 3: Conclusion:
The correct techniques are X-ray treatment, Pollen culture, and Distant hybridization.