| There are abundant germplasm resources in genus Actinidia in the world, including 66species and 118 intraspecies taxononic units. The varieties in A. chinensis and A. deliciosawere extensively cultivated in kiwifruit production. As a perennial vine fruit the growthperiod of kiwifruit is so long that the genetic study is not efficient by the routine researchmethod. The superposition in geographical distribution and the natural hybridizationresulted in emergence of many transitional biotypes, which makes the boundary ofinterspecies and intraspecies taxonomic unit confused and the research of genetics andvariation difficult. The genetics and variation in Actinidia were studied by analysis of genomic DNAsextracted by the improved CTAB method from 10 species including 42 biotypes. Theparameters of RAPD-PCR including the concentration of Taq enzyme, template DNA,magnesium ion, dNTPs and arbitrary primer were optimised gradually to establish theoptimal RAPD-PCR system, i.e. the total volume of the reaction was 20 μL, Taq enzymeconcentration was 1.0 unit, template DNA concentration was 4 ng·μL-1, MgCl2concentration was 1.25 mmol·L-1, dNTPs concentration was 0.25 mmol·L-1,arbitraryprimer concentration was 1.0 ng·μL-1. The schedule of RAPD-PCR program was 5 mininitial denaturation at 94℃, then 1 min denaturation at 94℃, 1 min anneal at 37℃, 2 minextension at 72℃, 40 cycles amplification, and 6 min final extension at 72℃. Thirty-eight arbitrary primers, which the amplified result of genomic DNA was fineand stable, were screened out from 80 ones, The RAPD-PCR of genomic DNA was carriedout by using of the 38 arbitrary primers. According to the data of RAPD-PCR coded in 0 or1 the cluster analysis was done by means of the Between-groups Linkage method and thecoefficient of Euclidean Distance Square (CEDS) in the software of SPSS 11.0 forWindows. The results of the cluster analysis showed that A. chinensis cv. 'Wuzhi No.2' becomea cluster with A. deliciosa cv. 'Yate' at 46.0 in CEDS, indicating the two species, A.chinensis and A. deliciosa, had closer relationship. A. deliciosa cultivars, 'Miliang No.1','Qingcheng No.1' and most A. chinensis cultivars clustered at 96.4 in CEDS, the wholecultivars in the two species clustered at 104.5 in CEDS, and the clustering order ofcultivars in different species in the dendrogram was alternant. So it was proposed that thetwo species should be divided into the same ones on the basis of RAPD analysis. 'ChuanmiNo.1' and 'Chuanmi No.2', 'Xuxiang' and 'Xuguan', 'Huamei No.1' and 'Huamei No.2',and 'Wuzhi No.2' and 'Wuzhi No.3' clustered respectively at a small amount in CEDSshowed that the clustering of kiwifruit cultivars had a trend of their native geographicaldistribution. The DNA fingerprint of special band had been constructed by RAPD analysis ofgenomic DNA in Actinidia. Twelve biotypes could be distinguished from 42 onesaccording to the DNA fingerprint. The new variety 'Wancui' was a natural mutant found in Actinidia deliciosa cv.Hayward published by the School of Horticulture, Anhui Agricultural University. Eighteencharacteristic bands between 'Hayward' and 'Wancui' had been amplified in 14 primers byRAPD-PCR in this experiment. It proved that the vegetative variation occurred in a widerange of genomic DNA. Two special bands, which molecular size was 740 bp and 649 bp, were chose from the18 characteristic bands between 'Hayward' and 'Wancui' to be separated, purified, clonedand sequenced. Two couple of special primer in 20 bp were designed and synthesized forthe PCR by the sequence charactered amplified region (SCAR). The result of SCAR-PCR amplification showed that one of the special bands, whichmolecular size was 649 bp, did not exist actually. There was a piece of special band whichmolecular size was 740 bp in the SCAR-PCR of 'Wancui' but not in that of Hayward.Therefore the special band which molecular size was 740 bp had been proved to be trueDNA fragment between 'Wancui' and Hayward. At the same time the RAPD maker ofgene...
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