摘要：The occurrence of low night temperatures during reproductive development is one of the factors most limiting rice yields in southern Australia. Yield losses due to cold temperature are the result of incomplete pollen formation and subsequent floret sterility. Researchers have found that in 75% of years, rice farmers suffer losses between 0.5 and 2.5 t/ha. Research is being undertaken to identify genetic materials that are cold tolerant under the local weather conditions and by using those genotypes as parent material, develop cold tolerance varieties of rice. A yield simulation model was used to measure reduction in losses due to cold at different minimum threshold temperatures, while the SAMBOY-Rice economic model was used to measure the costs and returns of a breeding program for cold tolerance. The results of the economic analysis reveal that incorporating selection for cold tolerance into the breeding program would lead to significant increase in financial benefits through a reduction in losses due to cold and an increase in yield from the better use of nitrogen by the cold tolerant varieties. The returns to investment in the change to the Australian rice breeding program are estimated to be high.
