Intraspecific inflorescence and palynological variations in the morphotypes of Amorphophallus paeoniifolius

Abstract

Abstract The genus Amorphophallus Blume ex Decne. is a vast and widespread group of aroids belonging to Araceae which is taxonomically and botanically distinct due to the frequency of emergence of inflorescences and their relatively short active period of existence. Amorphophallus paeoniifolius var. campanulatus or the elephant foot yam is an important tuber crop due to its high productivity and popularity as a vegetable in various delicious cuisines and medicinal properties. Wild congenerics of the cultivated A. paeoniifolius known as A. paeoniifolius Nicolson var. paeoniifolius (Decne.) Sivad. possess powerful therapeutic action against piles and gastro-intestinal disorders. The wide visible morphological variation observed in wild A. paeoniifolius morphotypes (morphological variants) available in the Western Ghats especially in the vegetative as well as inflorescence characters led to the present investigation to analyze and appraise the inflorescence diversity in comparison with other aspects, among the wild relatives of Amorphophallus paeoniifolius. Variation in the surface pattern of petiole and spathe is the main difference found within the species. The shape of appendix, the colour and pattern of spathe, scale leaves (bract) subtending the spathe, the male zone, female zone, the pollen morphology as assessed by SEM and pollen fertility showed distinct variation within the species revealing six distinct morphotypes. The mitotic chromosome studies indicated structural variation which was reflected in the karyomorphology. The ISSR markers, inflorescence /floral markers and vegetative morphological descriptors also indicated clear distinction between the morphotypes in addition to the variation seen in pollen morphology