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A Truncated F-Box Protein Confers the Dwarfism in Cucumber
- Lin, Tao, Wang, Shenhao, Zhong, Yang, Gao, Dongli, Cui, Qingzhi, Chen, Huiming, Zhang, Zhonghua, Shen, Huolin, Weng, Yiqun, Huang, Sanwen
- Journal of genetics and genomics 2016 v.43 no.4 pp. 223-226
- DNA, F-box proteins, breeding, cucumbers, dwarf cultivars, dwarfing, genomics, growth traits, loci, mutants, phenotype, plant architecture, recessive genes, single nucleotide polymorphism
- Dwarfism is an important plant architecture trait for cucumber breeding. In the present study, we identified a dwarf mutant 406M in cucumber which showed a shorter internode length as compared with its wild type. In a BC1F2 population from the cross of 406M with its wild type parental line 406, the segregation ratio fit 3:1 indicating the dwarf mutation was controlled by a single recessive gene. To identify the genetic basis of this mutation, we constructed a normal (N) and a mutant (M) bulk consisting 20 normal and dwarf plants, respectively. We re-sequenced the two DNA pools as well as the mutant line. SNPs between the two pools were identified, and SNP-index graphs were calculated and plotted. '(SNP-index) distribution identified 4 SNPs in cucumber chromosome 4 that were associated with the dwarf phenotype. Linkage analysis with the 4 SNPs in the BC1F2 population delimited the dwarf locus to a 2.04 Mb interval between the two markers dCAPS-SNP4G19847214 and dCAPS-SNP4G21882884. In this region, only dCAPS-SNP4G21398058 is co-segregating with the dwarfism phenotype, in which the cucumber gene Csa4G641640 encoding an F-Box protein was annotated. The SNP (C-to-T) mutation resulted in premature termination of the protein. Thus, genetic and genomic analysis pinpointed that the truncated F-Box Protein Csa4P641640 that was responsible for the dwarf phenotype in 406M.