Genetic analysis and molecular mapping of low amylose gene du12(t) in rice (Oryza sativa L.)
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We obtained interesting results for genetic analysis and molecular mapping of the du12(t) gene.
Control of the amylose content in rice is the major strategy for breeding rice with improved quality. In this study, we conducted genetic analysis and molecular mapping to identify the dull gene in the dull rice, Milyang262. A single recessive gene, tentatively designated as du12(t), was identified as the dull gene that leads to the low amylose character of Milyang262. To investigate the inheritance of du12(t), genetic analysis on an F2 population derived from a cross between the gene carrier, Milyang262, and a moderate amylose content variety, Junam, was conducted. A segregation ratio of 3:1 (χ 2 = 1.71, p = 0.19) was observed, suggesting that du12(t) is a single recessive factor that controls the dull character in Milyang262. Allelism tests confirmed that du12(t) is not allelic to other low amylose controlling genes, wx or du1. Recessive class analysis was performed to localize the du12(t) locus. Mapping of du12(t) was conducted on F2 and F3 populations of Baegokchal/Milyang262 cross. Linkage analysis of 120 F2 plants revealed that RM6926 and RM3509 flank du12(t) at a 2.38-Mb region. To refine the du12(t) locus position, 986 F2 and 289 F3 additional normal plants were screened by the flanking markers. Twenty-six recombinant plants were identified and later genotyped with four additional adjacent markers located between RM6926 and RM3509. Finally, du12(t) was mapped to an 840-kb region on the distal region of the long arm of chromosome 6, delimited by SSR markers RM20662 and RM412, and co-segregated by RM3765 and RM176.
KeywordsSimple Sequence Repeat Marker Amylose Amylose Content Ethyl Methane Sulfonate Allelism Test
This work was supported by a grant from the Next-Generation Biogreen 21 Program (PJ0080912013) of the Rural Development Administration, Republic of Korea. We sincerely thank Kyungpook National University for their donation (International Scholarship Scheme) to G. Kiswara.
Conflict of interest
- Juliano BO (1971) A simplified assay for milled-rice amylose. Cereal Sci Today 16:334–340Google Scholar
- Kinoshita T, Kikuchi H (1987) Inheritance of amylose content in crosses of low amylose mutants. Rice Genet Newsl 4:83–84Google Scholar
- Kiuchi H, Numao Y, Hirayama Y, Maekawa T, Kinoshita M, Aikawa M, Kikuchi H, Tanaka K, Tanno H, Satoh T, Shinbashi N, Taberi K, Sasaki K, Yoshida M, Maeda H, Sugawara K (2009) A rice variety “Ayahime”. Bull Hokkaido Prefect Agric Exp Stn 93:13–24Google Scholar
- Koh HJ, Heu MH (1997) Some mutants for grain quality in rice. In: Harmonizing agricultural productivity and conservation of biodiversity breeding and ecology Proceed 8th SABRAO Congress and Annual Meeting of Korean Breed Soc pp. 119–120Google Scholar
- Okuno K, Nagamine T, Oka M, Kawase M, Katsuta M, Egawa Y, Nakagahra M (1993) New lines harboring du genes for low amylose content in endosperm starch of rice. JARQ-Jpn Agr Res Q 27:102–105Google Scholar
- Shuichi I, Yoishihiro S (2004) A new rice cultivar with good eating quality (Low Amylose) and low glutelin protein, “LGCsoft”. Bull Natl Agr Res Center Western Region 3:57–74Google Scholar
- Wang C, Zhang Y, Zhu Z, Chen T, Zhao L, Lin J, Zhou L (2009) Development of a new japonica rice variety Nan-jing 46 with good eating quality by marker assisted selection. Mol Plant Breed 7(6):1070–1076Google Scholar