## 4 Discussion  
Divergent Diversity and Assembly of Phylosphere Microbial Communities among Spheneticola Species and Their Hybrids  
\(\alpha\)-diversity indices (Chao1, Shannon, and Simpson) revealed higher species richness and diversity in _S. trilobata's_phyllosphere microbial communities compared to _S. calendulacea_. The F1 hybrid exhibited comparable diversity and evenness to both parent groups, suggesting inheritance of a diverse, well-distributed assortment of microbial species, which may influence ecological interactions and adaptation [42]. \(\beta\)-diversity analyses (NMDS and UPGMA clustering) showed distinct bacterial community structures among _S. trilobata_, _S. calendulacea_, and the hybrid. While _S. trilobata_ consistently formed a separate group, _S. calendulacea_ and the hybrid displayed some shared membership, indicating heterogeneity or intermediate character in their assembly. This supports the influence of plant genotype, environmental heterogeneity, and microbial dispersal on plant-microb interactions [2; 4; 11; 24; 26]. Further research is needed to understand the drivers of both differentiation and occasional convergence in these phyllosphere communities [43]. These findings have potential ecological and evolutionary implications. _S. trilobata's_ higher microbial diversity may provide a competitive advantage over native species, offering a broader range of functional traits and potential benefits [44]. The shared membership between _S. calendulacea_ and the hybrid suggests certain microbial taxa are well suited to colonize both native and hybrid hosts, possibly due to adaptability to various environmental conditions or host genotypes [45]. Understanding the complex interactions between plants and their associated microbial communities is crucial for predicting the ecological and evolutionary consequences of these relationships. For example, the higher species richness and diversity in _S. trilobata_ may contribute to its success as an invasive species. A diverse microbiome can enhance plant resilience to environmental stressors and promote nutrient acquisition [11; 44]. Furthermore, the shared microbial membership between _S. calendulacea_ and the hybrid may facilitate gene flow between native and introduced species, potentially leading to the emergence of novel genotypes and phenotypes [42]. Chemosensitive Compounds and Invasive Success: The Role of Volatile Composition in S. trilobata's Dominance Over Native Plant Species  
Exotic species generate chemosensitive compounds that hinder the growth of indigenous plants through the volatilization of stems and leaves and the secretion of roots [37; 38]. Infusions from various parts of _S. trilobata_ negatively affect common crops like rice and tomato [46; 47]. The volatile composition of _Sphagneticola_ species differs, and examining their phyllosphere VOCs can shed light on the potent chemosensory effects of _S. trilobata_. Terpenoids, prevalent in the phyllosphere volatiles of the three _Sphagneticola_ species, possess excellent fungicidal properties and are commonly used in fungicides [48]. _S. trilobata_ has fewer VOCs with a relative content above 1% compared to native species and hybrids, but it has a higher relative content of compounds with fungicidal effects, such as \(\alpha\)-Phellandrene and Caryophyllene. The unique compound p-cymene, found in _S. trilobata_, has a relative content of 13.33%, second only to \(\alpha\)-Phellandrene and D-Limonene among all volatiles. p-Cymene exhibits various pharmacological properties, including antibacterial [49], antiparasitic [50], and antiviral activities [51]. Fold-change analysis reveals that the most downregulated volatile in _S. trilobata_ compared to _S. calendulacea_ and their hybrids is phenylethyl alcohol. This compound, which has an aromatic odor, is known to inhibit a range of pathogenic bacteria [52]. This evidence suggests that _S. trilobata_ contains more bacteriostatic volatile substances than _S. calendulacea_ and the hybrids. Studies have shown that the growth performance of _S.