Analysis Of Genetic Diversity Based On Morphological And Srap Markers Among Oil Flax Cultivars In China

Oil flax (Linum usitatissmum L.) is an annual herbaceous plant in Linaceae and Linum, it plays an important role in the development of the national economy. The analyzing genetic diversity of flax is very essential for its germplasms collection, conservation, classification, identification and improvement program. In the present study, a set of96accessions include different periods selected seeds of oil flax were employed to evaluate the genetic diversity of these resources using the morphological marker and SRAP marker.1. The suitable25μL SRAP reaction system was established by orthogonaldesign, and system contained:2.5μL10×Loading buffer, Mg2+3.0mmol/L, dNTPs0.25mmol/L, on each of0.2μ mol/L primer,1U Taq DNA polymerase,75ng template DNA. The PCR amplification program: per-denaturation3min at94℃,denaturation1min at94℃,37℃1min,72℃for1min,5cycles;94℃degeneration in1min,50℃for1min;72℃for1min,35loop; end loop,72℃for10min,4℃save.2.21polymorphic primers were selected using the oil flax DNA from169pairs of SRAP primers. These primers in flax amplified774bands, the poly-morphic bands of514,66.4%of total bands, the number of alleles per primer-varied from1~12, with polymorphic loci mean of3.2; There has very big difference in polymorphic markers loci was detected by different primer combinations.3.12traits such as period of duration, the cotyledon shape, cotyledon col-or, leaf shape, leaf color, fractal stem, fruit shape, plant height, length of the process, the number of branches, the number of grain per fruit, TKW (thousandkernal weight) were surveyed, and evaluated by using DPS software. All of the96accessions were classified into4groups when the Euclidean distance is5.76, The first group included87, the second group has5, the third group has3, the fourth group has only one is the cultivar named Ningya11, the first g roup could was divided into11subgroups when the Euclidean distance were be-tween5.11to4.18. All of accessions share the same traits could be concentrated together.4. According to the SRAP data, the calculated similarity coefficient among96accessions ranged from0.69to0.99. A dendrogram of genetic relationshipobtained by using NTsys2.01and PoPgene1.32. It showed that all the germplasms resources were classified into4groups at the similarity coefficient (GS) of0.69. The first group has85materials, the second group include6materials, t-he third group has3materials and the fourth group include only2materials,means that these materials of oil flax have high genetic similarity and complicated genetic relationships.5. Compare with dendrograms obtained from morphological marker and S-RAP molecular marker, we find that all of then can be used for assessment ofgenetic diversity and phylogenetic relationship in flax. But there is a degree of deviation among the identifying of the oil flax cultivars in China, because the SRAP markers reflect more differences on DNA level, and the genotypes ofmorphological markers have little relevance to the SRAP markers.