Abstract
With the inevitable risk posed by global climate change affecting crop yield and the ever-increasing demands of agricultural produce, crop improvement techniques need to be more precise in developing smart crop varieties. The rice crop, a staple food for the majority of the world population, has a significant role to play in alleviating the global hunger problem. With the world population burgeoning at an unprecedented rate, limited fertile land resources, climate change, emerging new races of pests and diseases and consumer preferences for quality attributes, it is imperative to increase crop diversity, and this requires better selection efficiency addressing the challenges of future rice production. Mutation breeding is a fundamental and very successful tool helping to increase crop diversity and allowing plant breeders to exercise their skill in developing desirable crop varieties. The induction of mutations has been used to enhance yield, improve nutritional quality and widen the adaptability of the world's most important crops such as wheat, rice, pulses, millets and oilseeds. India is considered to be one of the primary centres of origin of crop species with the concomitant very high genetic diversity in traditional landraces for different agronomic traits of economic importance. Plant architecture, such as plant height, branching habit (tiller number), leaf shape and patterns, floral and grain traits and quality traits such as aroma, amylose content and cooking quality are of tremendous importance for rice improvement programmes. Traditional landraces of rice have premium grain quality, fetching a premium price, but their cultivation is being marginalized due to their tall stature, proneness to lodging, late maturity and poor yield. Mutation breeding technology has been successfully implemented in rice improvement programmes, which have resulted in the improvement of aromatic rice varieties, such as 'Pusa Basmati 1', 'Dubraj and Jawaphool'. Two high-yielding mutant rice varieties, TCDM-1 ('Trombay Chhattisgarh Dubraj Mutant-1') and TKR Kolam ('Trombay Karjat Rice Kolam'), have been released for cultivation in Chhattisgarh and the Konkan region of Maharashtra. Both these varieties possess dwarf plant stature (110 cm), medium maturity (130 days), premium grain quality and resistance to major pests and diseases. Improvement of other traditional rice varieties is underway which will bring these varieties back into cultivation and help in improving the tribal and marginal farmers' economy.
Colonizing the atmosphere: a common concern without climate justice law?
