Introduction and exchange of improved bread wheat germplasm in the eastern gangetic plains of South Asia

Abstract

Wheat (Triticum aestivum L.) yield must be increased in the Eastern Gangetic Plains (EGP) of South Asia to improve the livelihoods of poor farmers. The International Maize and Wheat Improvement Center (CIMMYT) and its partners in South Asia initiated a regional yield trial, the Eastern Gangetic Plains Wheat Yield Trial (EGPYT) in 2000 to identify wheat cultivars with high and stable grain yield, superior agronomic traits and disease resistance. Advanced breeding lines from CIMMYT, Mexico and wheat programs in the region were assembled each year and tested at key sites in Bangladesh, India and Nepal. A total of 168 experimental genotypes and four checks were tested over eight years (2000–2007). The wheat genotypes showed arrays of genetic variation in grain yield, days to heading, plant height, 1000-kernel weight (TKW), and spot blotch severity in the eight years. Several experimental genotypes were superior to checks in yield, TKW, spot blotch resistance in individual country and across the region. We identified two sets of superior lines across the region that could be used as parents (Parent 1 = ‘BL1804’, ‘BL1968’, ‘BL2324’, ‘G162/BL1316//NL297’, ‘NL750’, ‘NL835’ and ‘Shatabdi’; Parent 2 = ‘BL2966’, ‘Milan/Shanghai#7’, ‘NL966’, ‘PBW373’, ‘BL3122’, ‘BL3124’, ‘BL3191’ and ‘SW89.5124*2/Fasan’) to develop new improved lines with high grain yield and TKW, spot blotch resistance, early maturity and acceptable plant height. New cultivars have been developed through this effort, and many outstanding lines selected by wheat breeders in the region are being used as parents in the breeding programs of different centers. This regional effort has helped in the introduction and exchange of superior wheat genotypes, thus enriching the germplasm base in the region. The findings underline the importance of region-focused varietal testing approach in developing and disseminating high yielding wheat germplasm.