Recently, the Center for Tobacco Genetics and Breeding of the Institute of Tobacco Research (TRI), Chinese Academy of Agricultural Sciences has made new progress in dissecting the genetic basis of cigar tobacco leaf morphological traits using GWAS and QTL mapping. The results were published in BMC Plant Biology.

Leaf morphology plays a crucial role in photosynthetic efficiency and yield potential in crops. Cigar tobacco plants, which are derived from common tobacco (Nicotiana tabacum L.), possess special leaf characteristics including thin and delicate leaves with few visible veins, making it a good system for studying the genetic basis of leaf morphological characters. In this study, GWAS and QTL mapping were simultaneously performed using a natural population containing 185 accessions collected worldwide and an F2 population consisting of 240 individuals, respectively. A total of 26 QTLs related to leaf morphological traits were mapped in the F2 population at three different developmental stages. Among the 206 significant SNPs identified in the natural population using GWAS, several associated with the leaf thickness phenotype were co-mapped via QTL mapping. By analyzing linkage disequilibrium and transcriptome data from different tissues combined with gene functional annotations, 7 candidate genes from the co-mapped region were identified as the potential causative genes associated with leaf thickness. These results provides valuable information for novel genes and molecular markers that will be useful for further functional verification and for molecular breeding of leaf morphological traits in cigar tobaccos and other crops in the future.

The first author of the paper is Yan Ji as Researcher at TRI. Associate Professor Guoxiang Liu from TRI and graduated Master student Sifan Yan are co-first authors. Dr. Yangyang Li from the China Tobacco Corporation Hunan Provincial Branch, Senior Agronomist Jun Wang from Sichuan Provincial Branch and Associate Professor Xingwei Zhang from TRI are co-corresponding authors of the paper. This research was supported by funding from Technology Innovation Project of Chinese Academy of Agricultural Sciences etc.

The article link is : https://doi.org/10.1186/s12870-024-05261-8