Recently, the researchers from Zhengzhou Fruit Research Institute successfully localized and cloned PavSCPL , a gene controlling sweet cherry fruit firmness through forward genetics, and analyzed its molecular function. The identification of PavSCPL provides a novel and invaluable genetic resource with potential for improvement of fruit firmness and present useful molecular markers for molecular-assisted breeding for fruit firmness in sweet cherry. The results were published in Plant Biotechnology Journal.

Fruit firmness is an important trait in sweet cherry breeding because it directly positively influences fruit transportability, storage, and shelf life. The researchers identified a candidate gene, PavSCPL , encoding a serine carboxypeptidase-like protein with natural allelic variation, that controls fruit firmness in sweet cherry using bulked-segregant analysis combined with fine mapping, quantitative RT-PCR analysis and gene cloning analysis in the ‘Rainier’ × ‘Summit’ F₁ population. A null allele harboring a 5.2-kb insertion in the second exon of PavSCPL gene that completely inactivated PavSCPL expression and resulted in the extra-hard-flesh phenotype. In addition, the researchers developed functional molecular markers for PavSCPL and the Pavscpl^5.2-k allele that co-segregated with the fruit firmness trait. Quantitative RT-PCR analysis revealed that the PavSCPL expression level was increased with fruit softening. Virus-induced gene silencing of PavSCPL enhanced fruit firmness.

By Qi Xiliang

qixiliang@caas.cn