Q.Importing better varieties and plants from outside and acclimatising them to local environment is called :

Bringing superior plant varieties from elsewhere and adapting them to a new locality, without any crossing, is called Introduction -- distinct from Selection, Heterosis, and Cloning.

Working

Plant breeders use several distinct methods to improve crop plants, and each has a specific, non-overlapping meaning in Plant Breeding:

• Introduction: a variety, cultivar, or species that already exists and performs well elsewhere is imported into a new region and is grown and acclimatised there, either used directly as a new crop or as a source of useful genes for further breeding. Because no hybridisation is involved, it is the fastest and cheapest way to add a new, useful genotype to a region's agriculture. Many economically important crops in India were originally introductions (for example, potato and tomato from South America, and rubber from Brazil).
• Selection: superior, naturally occurring variant plants already present within a mixed local population are picked out and propagated, without bringing in outside germplasm. …