Palynological studies and their implication in the compatibility of tuberose cultivars

Abstract

Determination of palynological characteristics of commercial cultivars is significant in determining the compatibility and intraspecific relationship, an essential criterion in tuberose breeding. As confirmed through various studies, self-incompatibility and seed sterility in tuberose have greatly hindered conventional breeding methods. However, the regulation of the incompatibility system and the principal factor behind it has yet to be thoroughly investigated. Understanding both male and female gametophytes and their functioning is a prerequisite that needs to be explored in tuberose. Seventeen tuberose genotypes studied showed the same inclination towards viability and germination, determining a positive correlation. Analysis of pollen morphology and ultra-structure using a scanning electron microscope (SEM) revealed marked variations among the genotypes. The distinct pollen ultra-structures revealed would serve as essential classification and character identification features in taxonomy. It also ascertains the pollen function as evidenced by the shrunken pollen of genotypes previously reported as sterile. These findings are vital to fully comprehending tuberose cultivars' breeding systems and reproduction biology.