Advances in breeding salt-tolerant rice varieties
2003
Mishra, B. | Singh, R.K. | Senadhira, D.
Major progress has been made in breeding salt-tolerant high-yielding rice varieties for various inland saline, coastal saline, and alkaline soils of fragile ecosystems. Of 32 salt-tolerant rice varieties developed by the Central Soil Salinity Research Institute (CSSRI), CSR10 was the first dwarf high-yielding salt-tolerant early-maturing rice variety released. Varieties CSR10 and CSR11 are popular as biological amendments for resource-poor farmers. CSR13 is a fine-grain salt-tolerant rice variety adapted to alkaline and inland saline soils and CSR27 possesses dual tolerance of coastal salinity and sodicity. Both varieties have been released across India. CSR27 possesses high tissue tolerance and high K+ and phosphorus-mining ability. We have successfully induced basmati qualities along with salt tolerance in CSR30, the first export-quality basmati rice. It has long slender, highly scented grains with good head rice recovery, high kernel elongation on cooking, intermediate gelatinizing temperature, and intermediate amylose content. A wide spectrum of rice germplasm (indigenous and exotic) has been evaluated and categorized for tissue tolerance, Na+ exclusion, K+ and P uptake, and reproductive-stage tolerance.We have combined different physiological mechanisms into one genetic background and these progenies show increased mining of P, K, and Zn and enhanced salt tolerance. However, no single physiological mechanism was found to be responsible for absolute salt tolerance. No correlation was observed for vegetative-stage salinity score with reproductive-stage salinity score and grain yield. Both additive and nonadditive gene effects for salinity tolerance, K+, and Na+/K+ ratio have been detected. Varieties CSR10, CSR1, CSR13, and CSR27 were the best combiners for salinity and alkalinity tolerance and related traits.
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