Identification Of Sweet Orange Clones In Hunan By Using Molecular Markers

Sweet orange is an important group of citrus cultivars, which includes a number of bud sport cultivars.There was abundant variation of sweet orange exist in Hunan. And the morphological description of sweet orange clones effected by environmental factors,we need to seek from the environmental impact of molecular markers to identify the Sweet Orange Clones from Hunan.In the present research,we collected 22 sweet orange clones (Citrus sinensis (L.)Osbeck),1 pummelo and 1 mandarin to study.Botany traits of sweet orange clones were analyzed,and their genetic variation were investigated by using SCo T marker with sequencing,ITS marker and SRAP marker. And results attained were as followings:(1) The analysis of botany traits showed that, sweet orange clones had different degrees of variation in leaf morphological traits, exterior fruit quality and interior fruit quality.(2) An SCo T-PCR system and amplification program suitable for the lab was set through the uniformity design,and the system and amplification program were:Each 20wL amplification reaction mixture consists of 10xPCR buffer,1.6 U Taq DNA polymerase,80 ng of DNA template,0.3 mmol/L dNTPs,0.2μmol/L primer and 1.6 mmol/L Mg2+.Amplification was performed under the following conditions:1 cycle of 4 min at 94℃;35 cycles of 1 min at 94℃,45s atannealing temperature,and 1 min at 72℃;a final extension of 8 min at 72℃.(3) 12 sweet orange clones can be identified by SCoT marker with sequencing; and 17 sweet orange clones based on nucleotide sequences from the ITS of the ribosomal DNA. However, we can't distinguish each one of these samples by using 143 SRAP primers. The result of this study indicated that sweet orange were closely related.