| The application of the combined technology system consists of molecular markers,anther culture and polyploid inducing to breeding of radish will be great helpful fordevelopment of radish which depends on the collection, analysis and innovation of radishgermplasm.In this paper, the analysis of the genetic diversity and identification of 17 radishes wasconducted with 107 RAPD primers, 4 pair of AFLP primes and 13 pair of SRAP primersand the possibility of employing the molecular markers to the research of geneticrelationship of radishes was discussed. The result showed that RAPD marker was thehighest polymorphic (93.4％) in three kinds of markers. The average 23.25 fragmentsamplified with AFLP prime combinations were obtained but with relatively lowerpolymorphic ratio. The dendrograms based on RAPD and SRAP data showed highconsistency with the classification according to the morphological traits, while the result ofAFLP markers analysis showed some difference. It could be concluded that the geneticdiversity of radish was associated with the color of fresh root skin and origin. Moreover, asfor revealing genetic relationships of different accessions in radish ,the data from severalkinds of markers analysis were more reliable than that from only one type of markeranalysis.In the part of anther and isolated microspores culture, three kinds of hormoneincluding KT, NAA and 2.4-D were employed to analyze the affecting of differentcombinations of hormone and genetypes on the initiation and differentiation of callus. Theresult showed that 0.2mg·L-12.4-D and 4mg·L-1KT in combination with 0.2 mg·L-1NAAwere effective for callus initiation. The combination of 4mg·L-1KT with 0.2 mg·L-1NAAresulted in fast growth of cellus and the foot differentiation of cellus was easy when theconcentration of NAA was 2 mg·L-1, but the bud differentiation was very difficult on anycondition. NAU-Yb-03 and NAU-Dy-13-03 were more sensitive to hormone than theothers in five varieties.In the research of polyploid induction of radish, two methods were applied to induce the polyploid of radish. First, the buds of vernalized seedlings of NAU-Dy-13-03 were dippedat first and third-leaves period in 0.3％colchicine solution with different times. Second, theunvernalized seeds of its were immerged in 0.1％colchicine solution at 12℃with differentlong time. The result showed that 100 percent of the treated materials survived and 50percent of polyploid-induced ratio was obtained when the materials were treated four timesin third-leaf period which was better than in first-leaf period. So it could be concluded thatboth the age of seedlings and times of treating were important for the effect of ployploidinduction of radish by buds-dipped method. The inducing degree with different long timeshowed gradual effect in seeds-immerged method, and hypocotyls became wider andmorphological character of leaves became more like that of polyploid obtained in the firstmethod when the treating time was from 3h to 6.5h. As for polyploid identification,morphologic character of leaves may play an important role.We can concluded that it is available to identify the germplasm of radish withmolecular markers, but it is more reliable with several markers than only one, since thedifferent distribution of various markers in the genome results in their genetic difference ofevolution. At the same time, the combination of hormone obtained in the research makes agood base of anther culture of radish, and the research of polyploid inducing makes itpossible to apply the polyploidy varieties of radish in the practice. |
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