Comparative Pollen Morphological Studies of Forest Plant Species of Leguminosae

Abstract

Pollen morphological studies of different forest plant species representing three families Fabaceae, Caesalpiniaceae and Mimosaceae of Leguminosae were undertaken.  Morphological characters were studied using microscopic study and the pollen key based upon differentiating characters was prepared. The diversified characters of the sporomorphs provide an important basis for generic and specific delimitations. Among the various categories of pollen morphological characters, the aperture is considered as primary and most conservative, exine ornamentation as secondary and other characters as tertiary in order of their importance. The four plant species belonging to Fabaceae i.e. Butea monosperma, Dalbergia sisoo, Gliricidia maculata and Pongamia pinnata showed similarities in aperture pattern but variations in shapes and sizes. The five plant species Bauhinia variegata, Cassia siamea, Delonix regia, Peltophorum pterocarpum and Tamarindus indica belonging to family Caesalpiniaceae showed the variations in exine pattern. The pollen types belonging to Mimosaceae i.e. Acacia arabica, Acacia nilotica, Albizzia lebbeck and Pithecellobium dulce are polyado-polyad excluding Prosopis juliflora i.e. monad. An attempt has been made to see how far palynology helps in taxonomy and throws light on the evolutionary trends. Pollen morphology is widely used in taxonomic treatments particularly with differences in exine structure and aperture forms. These investigations revealed that the palyno-taxanomic characters help to arrange the pollen genera and families bio-systematically. The data generated through the work will be helpful to taxonomist and modern palynologist to predict the relation between these three families of Leguminosae.