Question

Which of the following will be present in the F\textsubscript{1 multicellular embryo, derived from a cross of female plant (A) with male plant B, through "bulbosum method"?

• A. Chromosomes of A
• B. Homologous chromosomes of A and B
• C. Chromosomes of B
• D. recombinant chromosomes of A and B

Hint:

The "bulbosum method" is a classic example of using distant hybridization for haploid production. Remember that in this specific cross, the chromosomes of the wild parent ({H. bulbosum}) are always the ones that get eliminated.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The "bulbosum method" is a specific technique for producing haploid plants, particularly in barley. It involves a distant cross between cultivated barley (Hordeum vulgare) and a wild relative (Hordeum bulbosum). The key to this method is a phenomenon called uniparental chromosome elimination.
Step 2: Detailed Explanation:
The cross is set up as: Female plant A (H. vulgare) \(\times\) Male plant B (H. bulbosum).
Pollination and fertilization occur, forming a hybrid zygote that initially contains chromosomes from both parent A and parent B.
However, during the very early cell divisions of the embryo, the chromosomes from the male parent B (H. bulbosum) are systematically and selectively eliminated.
The resulting multicellular embryo is, therefore, haploid, containing only the set of chromosomes from the female parent, plant A.
This haploid embryo must be rescued via embryo culture before it aborts. The final embryo contains only the chromosomes of A.
Step 3: Final Answer:
The F\textsubscript{1} embryo will contain only the chromosomes of the female parent A.