Knob Composition in Northeastern Himalayan Maize

Knob-heterochromatin distribution studied in Northeastern Himalayan maize has revealed that, in general, the strains possess low knob number. There are significant differences in knob number among the strains collected from different altitudes of Sikkim ranging from 1200 to 2500 m. Strains occurring at higher altitudes of Sikkim. possess fewer knobs in comparison to the strains at lover altitude. The mean knob number among strains of low, medium and high altitude is 4.8, 2.9, and 2.2, respectively. The Sikkim Primitive strains have been classified into two groups, one having higher knob number (8–12), distributed in Sikkim and Tripura, and the other with lower knob number (1–4) represented by the strains front Meghalaya.