Title : Whole-transcripts studying of the synthetic allotetraploid Cucumis hytivus by Pacbio sequencing technique
The importance of wild Cucumis species for cucumber (Cucumis sativus L.; 2n=2x=14) improvement has long been recognized because they possess resistance to pathogens not present in Cucumber crop. Cucumis hystrix Chakr. (2n=2x=24 chromosomes) is the only sister species grouped as Cucumis subgenus together with C. sativus. C. hystrix is cross-compatible with cucumber, but the odd diploid number of chromosomes leads to sterile in interspecific hybrid(2n=19; 7 from cucumber and 12 from C. hystrix). The fertility was restored by chromosome doubling via somaclonal, consequently a new allotetroploid(2n=38) was synthesized and named Cucumis hytivus J.-F Chen & J. H. Kirkbr. As the offspring of C. sativus and C. hystrix, C. hytivus confers critical roles for cucumis subgenus either in significantly enriching the gene pool of cucumber or in understanding the process of revolutionary and evolutionary changes triggered by hybridization and allopolyploidization among the cucumis species.