High-yielding, drought-tolerant, stable rice genotypes for the shallow rainfed lowland drought-prone ecosystem

摘要

High and stable yield of rainfed lowland rice is important for sustainable rice production and food security. Many varieties grown on large holdings in rainfed areas provide good yield under normal water availability but suffer high losses in the event of drought. From a set of 129 genotypes tested in shallow rainfed drought-prone environments at three locations in eastern India from 2005 to 2007, a subset of 39 genotypes that were tested for two or more years under favorable irrigated, moderate reproductive-stage drought stress, and severe reproductive-stage drought stress situations in 16 environments was selected for a GGE biplot analysis to identify genotypes that provide stable yield across environments. IR74371-70-1-1 and IR74371-46-1-1 were identified as stable genotypes showing high yield under varied environments across different sites. IR36, IR64, and MTU1010, the three popular varieties grown on large holdings in rainfed areas but bred for irrigated ecosystem, as well as improved genotypes CB2-458, DGI237, R1027-2282-2-1, RR272-21, IR67469-R-1-1, and IR66873-R-11-1, and varieties PMK1 and PMK2 released for rainfed ecosystems performed well only in irrigated non-stress environments and were not found promising in drought environments. Improved genotypes ARB6, ARB2, ARB5, ARB7, ARB8, RF5329, CB0-15-24, IR72667-16-1-B-B-3, IR74371-78-1-1, and IR55419-04, and drought-tolerant released varieties Tripuradhan. Armada, and Poornima performed well only in drought-stress environments. The identification of improved genotypes with ability to provide stable high yield across variable environments and their release for cultivation by farmers will enable farmers to reap high yield and stable income. (C) 2012 Elsevier B.V. All rights reserved.