Comparison And Analysis Of Quantitative Loci For Quality Traits In Rice (Oryza Sativa L.) Under Lowland And Upland Cultivation

Using 116 DH(Double Haploid) individuals derived from the cross of upland rice IRAT109 (Japonica ) with paddy rice Yue Fu(Japonica), rice quality traits including content of crude protein, brown rice, milled rice, head milled rice, amylose content, gel consistency, alkali value, chalkiness, grain length, grain width and length width ratio, were compared and analysed on lowland and upland cultivation. QTLs confonning those quality traits were mapped using a set of 165 IRAT109/Yuefu DH population, an linkage maps with 94 RFLP marker loci and 81 SSR marker loci, and a mixed model approach(QTLMapper V1.0).Differentia analyzed by programs developed by SPSS indicated the change of each rice quality characteristics was occurred differently. The content of crude protein, head milled rice, gel consistency and alkali value were higher, and chalkiness, grain length and grain width were lower in the upland cultivation than that in the lowland cultivation. In general, most of characters of rice grain quality were improved in the upland cultivation comparing with that in the lowland cultivation. The content of crude protein, head milled rice, gel consistency and alkali value were sensitive to water-stress and influenced stronger by soil water situation than amylose content, grain length, grain width and Chalkiness. Especially, the content of crude protein increased 37.9% or 3.02 percentile in the upland cultivation than that in the lowland cultivation. But brown rice, milled rice and length width ratio of were not influenced by cultural environment.Correlation analysis indicated that milling quality traits had the interaction with environment (culture system), but the looking, cooking and nutrition quality characters mainly controlled by genetic factor. Therefore, the grain quality of the lowland or upland rice varieties with drought-resistance could be improved under upland condition or dry-cultivation by the cross between elite grain quality lowland rice cultivar and drought-resistant upland rice cultivar.23 main effect QTLs and 22 pairs epistatic QTLs were detected for the milling, looking, cooking and nutrition quality traits. 4 main effect QTLs and 18 pairs epistatic QTLs were founded to be affected significantly by environments, the proportion of phenotypic variation explained by individual QTLxenvironment interaction ranged from 8.99% to 47.86%.