Step 1: Understanding autotetraploid.
An autotetraploid is a polyploid organism with four sets of chromosomes derived from a single species. It is usually developed for increased biomass and forage quality.
Step 2: About 'Pusa Giant'.
‘Pusa Giant’ is a famous variety of berseem (Trifolium alexandrinum), a widely cultivated fodder crop in India. It was developed as an autotetraploid to improve yield and adaptation.
Step 3: Checking options.
- Bean: No such autotetraploid called Pusa Giant.
- Berseem: Correct, ‘Pusa Giant’ is an autotetraploid variety.
- Tomato: Pusa varieties exist, but not as an autotetraploid named ‘Pusa Giant’.
- Egg plant: No such autotetraploid variety named Pusa Giant.
Step 4: Conclusion.
Thus, ‘Pusa Giant’ is an autotetraploid of berseem.