Vavilov’s Primary Gene Centre: Origin of Crop Plant Diversity

According to Nikolai Vavilov, crop plants evolved from wild species in regions of maximum genetic diversity, known as the primary gene centre.

Correct Answer

The correct option is 3. Primary gene centre. Vavilov stated that crop plants evolved from wild species in areas showing the greatest diversity and richness in variation, calling these the primary centres of origin.

These regions feature high genetic variability, wild progenitors, and dominant genes shaped by natural selection.

Option Explanations

• 1. Secondary gene centre: These are areas away from the original site where crops spread and adapted, showing diversity from cultivation but not the maximum variation or wild forms.

• 2. Non-centre: This term lacks recognition in Vavilov’s framework; it does not describe any region of crop origin or diversity.​

• 3. Primary gene centre: Matches Vavilov’s definition exactly—the original homeland with vast genetic diversity, wild traits, low crossing over, and natural selection driving evolution.

• 4. Centre for plant genome: No such concept exists in Vavilov’s theory; it refers vaguely to genomics, unrelated to his centres of origin model.​

Vavilov’s Theory Overview

Vavilov identified eight primary centres (e.g., Mexico for maize, China for rice) and secondary ones, emphasizing mountains and foothills for primitive agriculture.

His work revolutionized crop breeding by highlighting genetic resource conservation from these diversity hotspots.