Major Crops Chromosome Numbers & Origin Matrix
Chromosome numbers and centers of origin are guaranteed scoring questions across ICAR JRF, ASRB NET, and State PSC papers.
| Crop Species | Botanical Name | Somatic Chromosome (2n) | Primary Center of Origin |
|---|---|---|---|
| Rice (Paddy) | Oryza sativa | 2n = 24 (Diploid) | South-East Asia (Indo-Burma) |
| Bread Wheat | Triticum aestivum | 2n = 42 (Hexaploid) | South-West Asia |
| Maize (Corn) | Zea mays | 2n = 20 (Diploid) | Central America & Mexico |
| Chickpea (Gram) | Cicer arietinum | 2n = 16 (Diploid) | South-West Asia (Mediterranean) |
| Pigeonpea (Arhar) | Cajanus cajan | 2n = 22 (Diploid) | India / South Asia |
| Groundnut (Peanut) | Arachis hypogaea | 2n = 40 (Allotetraploid) | Brazil / South America |
| Mango | Mangifera indica | 2n = 40 (Allotetraploid) | Indo-Burma region |
| Cotton (American) | Gossypium hirsutum | 2n = 52 (Tetraploid AADD) | Central & South America |
Pollination Behavior Classification
Self-pollinated (Autogamous): Rice, Wheat, Barley, Oats, Chickpea, Pea, Tomato, Potato.
Cross-pollinated (Allogamous): Maize, Pearl Millet (Bajra), Sunflower, Castor, Cucurbits, Cabbage, Cauliflower.
Often cross-pollinated: Sorghum (5-25%), Cotton (5-25%), Pigeonpea (5-40%).
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