Question

K. J. Kasha and coworkers found that following the cross between Hordeum vulgare \(\times\) Hordeum bulbosum, chromosomes of H. bulbosum were eliminated in early zygotic division, so few days after pollination, embryos can be cultured to get haploids. This method is called as -

• A. Delayed pollination
• B. Distant hybridization
• C. Nucellus culture
• D. Androgenesis

Hint:

When you see a cross between two different species (like {H. vulgare} and {H. bulbosum}), the overarching term for the technique is {Distant Hybridization}. The specific outcome here is haploid production, but the method itself is hybridization.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The question describes a specific technique for producing haploid plants of barley (Hordeum vulgare) and asks for the scientific name of this method.
Step 2: Detailed Explanation:
The described process involves several key features:
A cross is made between two different species: Hordeum vulgare (cultivated barley) and Hordeum bulbosum (a wild relative). A cross between different species is known as interspecific or distant hybridization.
After fertilization, the chromosomes of one parent (H. bulbosum) are selectively eliminated from the cells of the developing embryo.
The resulting embryo is haploid, containing only the chromosome set from the H. vulgare parent. This embryo is then rescued and cultured in vitro to grow into a haploid plant.
The entire process is a form of distant hybridization that is specifically exploited for haploid production through chromosome elimination.
Nucellus culture is used for cloning from maternal tissue.
Androgenesis is haploid production from male gametes (pollen).
Step 3: Final Answer:
This method of producing haploids via an interspecific cross followed by chromosome elimination is a specific application of distant hybridization.