Comprehensive morphological, anatomical, and molecular characterization of native and non-native Senna species (Fabaceae) in Qatar

Abstract Ancient plants are under intense selection pressure due to rapid climate change, habitat destruction, and the increasing introduction of invasive species. Senna ( Cassia ) native to desert region like Qatar, are tolerating immense environmental stress and considered as threatened. This is the first comparative analysis of native S. italica and non-native S. occidentalis from Qatar, characterizing their differential morphological, anatomical, and genetic features through microscopic observation, and PCR amplification of microsatellite-based molecular markers, respectively. Some contrasting physiological and anatomical features, such as differences in root structures, absence of pith in S. occidentalis , denser leaf stomata and greater number of trichomes in S. italica assisted to distinguish between native and non-native Senna species. Moreover, normal-field-grown S. italica seeds exhibited the presence of more macro and trace elements than desert-grown plants. Further, ISSR and SSR marker-based PCR confirmation and statistical assessment of genetic diversity within and among S. italica populations showed no polymorphisms. The presence of a single haplotype ( N eh ) in each population, null genetic diversity within populations ( H e ), and the proportion of total genetic differences ( F st ) confirmed the genetic homogeneity. In contrast, presence of polymorphic loci shown by selected ISSR and SSR markers in two species, along with total gene diversity ( H t ) = 0.5 and genetic differences ( F st ) = 1, assured genetic differences between them. Additionally, based on functional annotations of genes associated with the markers in Fabaceae, we identified several key genes pertinent to plant biological processes, reproductive and developmental functions, plant adaptation, and yield. This study demonstrated how efficient differentiation between native and non-native plant species can preserve the biodiversity of sensitive desert regions, reducing the risk of extinction and species transition for heritage plants.