Q.Differentiate primary introduction from secondary introduction.

Primary introduction releases an exotic variety unchanged; secondary introduction uses it as breeding material to develop an improved new variety.

Plant introduction is the process of bringing new plant genotypes or varieties from one region/country into an area where they were not previously grown, and it is of two kinds:

1. Primary introduction: the introduced plant variety is found to be entirely suited to the new environment, performing well without requiring any change, and so it is multiplied and released for commercial cultivation exactly as it was introduced, with no further breeding or selection involved.

2. Secondary introduction: the introduced variety is not directly suitable for release as it is, but it possesses some desirable character(s) (such as disease resistance or high yield); it is therefore used as a parent in a breeding/hybridisation programme, crossed or selected together with locally adapted varieties, and subjected to further selection over generations, so that only the resulting improved, locally adapted variety is eventually released for cultivation.

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