Construction Of Mapping Population Of Gracilariopsis Lemaneiformis (Rhodophyta) And Screening Of SSR And RSAP Marker From Their Parents

Gracilariopsis lemaneiformisis is an important macroalgae, which has greateconomic and theoretical research value. The cultivation scale has expanded year byyear and industrialization has been achieved, however., the molecular breedingsystem is not available at present. The main breeding way ofGracilariopsis lemaneiformisis is traditional means that using artificial selective andmutation breeding techniques, taking a long time and heave workloaded so thataccelerating its molecular breeding process seems urgent. A genetic linkage map ofhigh density is essential to achieve molecular-assisted breeding and quantitative traitlocation and developing enough DNA markers is necessary to construct a geneticlinkage map. Simple Sequence Repeat is one of the ideal choices used ingenetic linkage mapping and QTL mapping for the existence of a point with a lot ofallele; rich polymorphism; Mendelian inheritance; co-dominant genetic markers andreliable results. Restriction site amplification polymorphism is a new DNA markertechnique, combination multiple molecular markers’ characteristic and its randomprimers could bind genome specific restriction and finish amplification just by onePCR reaction to detected the varieties restriction sites in genome easily. It also can beused to construct genetic linkage map.Mapping population must been established first for genetic mapping. Select ZC(tetrasporophyte) strains and induce it releasing gametocytes, then choose female andmale gametocytes with big differences as parents for hybridization. Two mappingpopulations,♀3×♂8and♀6×♂9are obtained and get their F1generation. This isthe first application to use the genome information offeredby second-generation sequencing technology to synthesize SSR primers to screenpolymorphism between hybrid parents; verifying the reliability of second-generation sequence technology, providing available polymorphic markers for the latter geneticlinkage mapping and making the foundation for future study.15polymorphic markersbetween♀3and♂8and8polymorphic markers between♀6and♂9are obtainedby SSR screening.88polymorphic markers between♀3and♂8and93polymorphicmarkers between♀6and♂9are obtained by RSAP screening. All of these markerscan be used in next step. Calculating the genetic distance between the two pairsof parents by two kinds of markers, the genetic distance by SSR between♀3and♂8is0.0712, while♀6and♂9is0.0436and the genetic distance by RSAP between♀3and♂8is0.2284, while♀6and♂9is0.2537. It’s obvious thatdifferent hybrid combinations should be chosen because the difference of markersThis paper also compares the two kinds of markers, that RSAP is much higher thanSSR at the number of loci per primer set and the number of polymorphic loci perprimer set and the former is respectively4.99times and12.93times of the latterbetween♀3and♂8while it shows5.81times and25.5times between♀6and♂9.Thus, RSAP can provide more information by each test and is more suitable forconstructing genetic linkage map of Gracilariopsis lemaneiformis.