Practice question

During 1963-64 Indian scientists tested Mexican dwarf wheats at IARI and multiple coordinated centers. Among introduced germplasm, Lerma Rojo 64 and Sonora 64 consistently produced 4 to 5 tons per hectare compared to 0.8 to 1 ton from tall Indian landraces NP4 and NP52. Sonora 64 itself descended from cross Yaqui 50 x Norin 10-Brevor, carrying Rht genes for reduced height. From a yellow grain mutant of Sonora 64 selected under gamma irradiation in India, Kalyan Sona was developed by S.P. Kohli, noted for amber grain and wide adaptation. Sonalika was selection from same Mexican bulk, later designated HD 1553. Both varieties matured early, responded to irrigation, showed resistance to brown rust genes Yr and Lr, and possessed high harvest index. Their rapid release in 1965 catalyzed Green Revolution, leading to subsequent elite lines like Safed Lerma and Chhoti Lerma through regional selection. This understanding supports competitive exam preparation for NEET, GATE and CSIR NET concepts linking genotype with phenotype through molecular pathways involving transcription factors, hormones and metabolic enzymes that regulate development, adaptation and reproductive biology in applied breeding programs.