Abstract: Glandular trichome secretions of cigar tobacco leaves are rich in aroma precursors such as cembrane diterpenes, labdane diterpenes and sucrose esters, which are closely associated with the formation of tobacco leaf quality and flavor characteristics. To breed high-secretion cigar tobacco cultivars, this study used Guyin 4 as the recurrent parent and the high-glandular-trichome mutant HND1 as the donor parent. An improved cigar line JX28 with dense glandular trichomes was developed through multi-generation backcrossing and screening, and comparative studies were carried out on its growth performance, chemical composition and air-curing characteristics.The results showed that JX28 shared generally consistent agronomic traits with Guyin 4, but had wider and rounder leaves, enhanced leaf oiliness, and obviously branched glandular trichomes on the leaf surface, with a 42.85% increase in gland head density. The content of glandular trichome secretions in mature leaves increased significantly, and the contents of cembrane diterpenes, labdane diterpenes and sucrose esters rose by 57.08%, 65.50% and 43.22%, respectively. During all air-curing stages, JX28 had higher total nitrogen content, potassium content, sugar-alkaloid ratio, nitrogen-alkaloid ratio and potassium-chloride ratio than Guyin 4, while its total alkaloid content was significantly lower. After air curing, the content of neutral aroma components in JX28 tobacco leaves was remarkably elevated, and the degradation products of cembrane-type, labdane-type and sucrose ester-type compounds increased by 45.00%, 79.67% and 53.65%, respectively.Microbiome analysis revealed shifts in the microbial community structure of air-cured tobacco leaves between JX28 and Guyin 4. The relative abundance of bacterial genera Pseudomonas and Sphingomonas, as well as fungal genus Aspergillus, was higher in JX28, while the relative abundance of Methylobacterium and Aureobasidium decreased. The relative abundance of Pseudomonas and Aspergillus was significantly positively correlated with the content of glandular trichome secretions, whereas the abundance of Aureobasidium and Colletotrichum showed a significant negative correlation with the secretion content.These findings demonstrate that increasing glandular trichome density and secretion content can optimize the chemical composition and microbial community of tobacco leaves, thereby improving leaf quality, which serves as an important strategy for cigar tobacco cultivar improvement.