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Microsatellite or simple sequence repeat (simple sequence repeats, SSR) is present in the expressed sequence tag (expressed sequence tags, ESTs). Wheat EST sequence database development, EST-SSR markers, ordinary wheat EST sequence (GenBank / dbEST registered 2006.4.18 ~ 2007.2.4) SSR Find feature analysis, EST-SSR primer by Primer5.0 software design, the choice of three wheat varieties the validity detection, the use RIL groups and Mapmaker/Exp3.0 of software for genetic mapping. RIL population seedling stage nutrient absorption traits were measured and QTL analysis. The main results are as follows: (1) 265,362 ordinary wheat EST sequences were found in the 6314 SSR, accounting for 2.38% of the entire EST database. Wherein the dinucleotide, trinucleotide repeat the primitives proportion significantly greater than four nucleotides, the five nucleotide type. Higher repetition frequency of occurrence primitive type, dinucleotide, trinucleotide repeat most primitive types. GA / CT in EST widespread, is the most frequently repeated primitive types. Primitive AG / TC dinucleotide CA / GT, AC / TG ??also the frequency of higher ground, AT / TA and TA / AT lower frequency, GC / CG and CG / GC does not appear. Trinucleotide repeat primitive CAA / GTT CGG / GCC higher frequency, followed CGC / GCG, GGC / CCG CTT / GAA TGC / ACG, GAG / CTC, GTT / CAA ACA / a TGT GCT / CGA, CAG / GTC nine kinds of repeat motifs appear higher ground frequency. Four, the the pentanucleotide type only GGAC / CCTG CGATA / GCTAT GACGA / CTGCT higher frequency of occurrence, and the remaining repeat motifs lower frequency. (2) types of dinucleotide repeat motifs appear that the number of repetitions of many types, large span. Trinucleotide number of repetitions of the primitive type and span of less than dinucleotide. GA / CT and AG / TC number of repetitions type up, span, CA / GT and AC / TG, AT / TA, TA / AT, etc. There are a large number of repetitions span. In The trinucleotide primitives, CAA / GTT, ACA / TGT GTT / CAA, the GAA / CTT, CTT / GAA TGC / ACG, TCT / AGA also has a large number of repetitions, and compared to a variety of number of repetitions type appear other The repeat motifs multi-appears to repeat 7,8,9 three the number of repetitions type. Tetranucleotide and pentanucleotide repeat the primitive multi 4,5,6,7 times to repeat in the 1 to 2 the number of repetitions type. (3) were designed based on microsatellite sequences screened 596 EST-SSR primer pairs, select one of more than 194 synthetic 95 points. PCR showed that 165 primer pairs (85%) can be amplified by a stable and clear with type; these primers can be used as the new EST-SSR markers in wheat. 20 primer pairs to a stable and clear polymorphism is detected in the RIL-8 between the two parental detected polymorphism difference is obvious, some primers 2 and above the bit point difference detected. (4) 36 20 EST-SSR primer sites detected in the RIL population polymorphism, the 24 sites were integrated into the existing genetic map of wheat. Involving 1B, 1D, 2D, 4A, 5A, 5B, 5D, 6A, 6B chromosome 9. Increase the length of the map, and rich in the number of functional markers. In addition, according polymorphisms (SNPs) in the A, B, D group chromosome distribution can be used as an indicator to determine the degree of chromosomal variation. (5) A total of nine QTL wheat seedling stage nutrient absorption related traits, distributed in six linkage groups, parsing 8.63% to 66.16% of the phenotypic variation. Provide a theoretical basis for further understanding of nutrient uptake mechanism and to determine its genetic law.
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