Correlational analysis of halotolerant palynomorphs peculiarities by integrating morphological and morphometric characterization using scanning electron microscopy

Pollen analysis of halophytes is crucial for their accurate identification and taxonomic classification within respective families. This study aimed to highlight the systematic pollen analysis of 15 dominant halotolerant species from twelve families collected in the Kalabagh Salt Range, Pakistan. Light microscopic (LM) and scanning electron microscopic (SEM) techniques were used to examine the pollen’s discriminative traits that support the phenetic grouping and morphometric differentiation among halotolerant taxa. Pollen exine sculpture varied from punctate, verrucate, microechinate, perforate, to reticulate. Pollen shape also exhibited variance ranging from oblate-spheroidal (4 spp.), prolate (3 spp.), prolate-spheroidal (3 spp.), subprolate (3 spp.), Oblate (1 sp.) to spheroidal (1 sp.). The high pollen viability value of Euphorbia caducifolia (92.75%) describes its ecological adaptation to a saline environment. Principal component (PCA) and cluster analysis were used to analyze pollen morphometric data, revealing strong affinities among the studied halotolerant. Morpho pollinic traits, combined with advanced systematic tools, are crucial for identifying lineages within morphogroup taxa and may contribute to the taxonomic position of halotolerant plant species.