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        검색결과 1

        1.
        2015.07 서비스 종료(열람 제한)
        Banaue Rice Terraces in the Philippines has been a rich source of genetic diversity of untapped rice landraces in the mountainous region of Cordillera. Although some may have been included into modern breeding programs, significant indica-japonica differentiation among landraces cultivated in the region is not well known. Thus, Cordillera landraces differentiation across different altitude gradient (458 m to 1830 m) will provide great opportunities for improvement on rice genetics. We analyzed the genetic variation among 166 accessions collected in 17 towns in 6 provinces across different altitudes using Subspecies Specific Sequence Tagged Site (SS-STS) and Insertion-Deletion (InDel) markers. Subspecies Prototype Index (SPI) degree of each landrace was used to calculate the genomic inclination of each variety towards subspecies. The 50 molecular markers (24 SS-STS and 26 InDel) that assayed variation in 166 accessions revealed 116 alleles. Gene diversity ranged from 0.04 (R3M23) to 0.50 (S04058) with an average of 0.40. Polymorphism information content (PIC) ranged from 0.04 (R3M23) to 0.37 (S12030, S07047, R10M40, S10001, S04058 and S09040B) with an average of 0.31. Using the control varieties to assign groups, the larger group of 114 Cordillera landraces corresponds to 71% japonica type while the smaller group of 42 corresponds to 26% indica and 3% intermediates. A total of 7 (4%) indica and 9 (6%) japonica type accessions were found above 1500 m. Results of this study suggested that majority of japonica type rice landraces were grown in high altitudes of Banaue Rice Terraces and nearby provinces, and interestingly, indica type rice landraces were cultivated in areas at much higher altitudes (>1500 m) than those categorized by the traditional methods.