Palyno-morphological investigations of halophytic taxa of Amaranthaceae through SEM from Salt range of Northern Punjab, Pakistan

Abstract

The pollen morphology of 11 salt tolerant plant species of family Amaranthaceae from the salt range of Northern Punjab, Pakistan has been studied. The palyno-morphological characters were examined using light and scanning electron microscope. The examined all salt tolerant species have a slight difference in size but have similarity in shape, pore ornamentation, and polarity. The observed morphological characters of pollen grains were pollen symmetry, size, shape, pore ornamentation, pore size, number of pores, exine thickness, polar and equatorial diameter and, P/E ratio. Apolar type of pollens has been observed in all species. Shape of pollens was spheroidal. Exine sculpturing of pollen grains was scabrate (six spp), microechinate (four spp), and microechinate-scabrate (one spp). Different pori numbers were observed in different species. The pantoporate aperturate and sunken pore ornamentation have been reported in all species. A pollen taxonomic key was developed using examined morphological characters for the accurate identification of halophytic taxa. The high fertility and low sterility of pollens confirmed that the selected halophytes are well-established in the salt region. The findings highlight the taxonomic significance of pollen morphology in correct identification and differentiation of salt tolerant plant species.

Keywords: Amaranthaceae; SEM; halophytes; palyno-morphology; taxonomy.