Q.Differentiate primary introduction from secondary introduction.

Plant introduction is bringing a genotype from where it normally grows into a new place or environment — for example, rice variety IR8 introduced from the Philippines, or wheat varieties Sonora 63/64 from Mexico. The introduced plant must acclimatize to its new environment, and every introduction must pass through quarantine to keep out weeds, insects or disease. Introduction is primary (the imported variety is used unchanged because it is already well adapted) or secondary (the imported variety is selected and …