Physical Localization Of 18 Markers In The Linkage Group 8 And 9 Of Genetic Map Of Hevea Brasiliensis

Hevea brasiliensis,a perennial tropic crop,belongs to the family Euphorbiaceae.In this study,with using Reyan ’7-33-97’ of Hevea brasiliensis as experimental material,18 markers were physically located by fluorescence in situ hybridization technique(FISH)or in situ PCR(IS-PCR)technique,which were from two genetic linkage groups of Hevea brasiliensis genetic map constructed by Lespinasse in 2000.And the physical positions of these markers were integrated with the genetic linkage map.Our results will provide useful informations for molecular assisted breeding,germplasm identification and comparative genomics of rubber tree.The results of this study were as follows:First,18 genetic markers were selected from linkage groups 8 and 9.Including 16 RFLP markers sites and 2 SSR markers sites.Second,FISH was performed on 11 genetic markers gHbCIR504.RO,gHbCIR678,gHbCIR236,gHbCIR498.RO,gHbCIR692,gHbCIR498.PB,M197,gHbCIR83,gHbCIR643,M630,and gHbCIR358 on linkage group 8.The results of karyotypic integration revealed that 11 genetic markers were located on chromosome 5 of the rubber tree Reyan ’7-33-97’.Two markers(gHbCIR504.RO and gHbCIR236)were located on the short arm of chromosome 5,and the percentage distances from centromere to signal loci was 73.95 and 25.67.While,the markers gHbCIR678,gHbCIR498.RO,gHbCIR692,gHbCIR498.PB,M197,gHbCIR83,gHbCIR643,M630,and gHbCIR358 were located on the long arm of chromosome 5,the percentage distances from centromere to signal loci was 13.82.,18.60,19.17,28.61,35.07,49.61,58.95,69.95 and 74.93,respectively.The linkage group 8 corresponded to the chromosome 5,and the cytogenetic map of chromosome 5 was constructed.Finally,7 genetic markers(gHbCIR568,gHbCIR95/331,gHbCIR280,gHbCIR666.L2,and gHbCIR380)and IS-PCR(gHbCIR184 and gHbCIR257)from the linkage group 9 were detected by FISH.The results revealed that 7 markers were located on chromosome 1.Two markers gHbCIR568 and gHbCIR184 were located on the short arm of chromosome 1,and the percentages of signal loci to centromeres were 35.78 and 25.20,respectively.While,the markers gHbCIR95/331,gHbCIR280,gHbCIR666.L2,gHbCIR257,and gHbCIR380 were located on the long arm of chromosome 1,and the percentages of signaling sites to centromeres were 21.33,31.35,46.40,47.78,and 57.77,respectively.The linkage group 9 corresponded to the chromosome 1,and the cytogenetic map of chromosome 5 was constructed.