From Millet’s ‘Pearl’ To Desert’s ‘Gold’: GHB 538 Improved (Maru Sona) Emerges through Genomics-assisted Breeding

Abstract

Downy mildew (DM) is the most devasting disease of pearl millet caused by Sclerospora graminicola (Sacc.) Schroet, remains a major biotic constraint to pearl millet production in India. Looking to this constraint, Junagadh Agricultural University, Junagadh (Gujarat), in collaboration with ICRISAT (International Crops Research Institute for the Semi-Arid Tropics), Hyderabad, decided to improve notified popular pearl millet hybrid GHB-538 through marker-assisted backcross breeding due to which this hybrid make a comeback in as improved version. Christened Maru Sona or Desert Gold in the local language, the new version is equipped with the genes to fend off devastating downy mildew disease and was released for cultivation in Gujarat state and A1 zone dry regions of Rajasthan, Gujarat, Haryana during kharif season. The pearl millet hybrid GHB 538 Improved was developed by introgression of downy mildew resistance QTLs from P7-3-P13 and 863B-P2-P7 lines in the pollen parent J-2340 of earlier released GHB-538 with marker-assisted backcross method using foreground selection and notified at state and national level for kharif season cultivation. The screening against downy mildew of GHB 538 Improved was carried out under the downy mildew sick plot, and yield trials testing work against original GHB-538 was carried out at state and national levels across different locations. In comparison to the original hybrid, Maru Sona shows markedly high resistance to downy mildew disease along with an increase in grain yield (3.5 and 1.8%) and dry fodder yield (10.8 and 1.9%); it also hallmarks early flowering (44 and 45 days) at state and AICRP testing, respectively. It also shows resistance reaction to other pearl millet diseases and possesses good quality parameters