SEM-based study for palynological and pollen germination of Lilium longiflorum cv. Pavia

Abstract

Pollen is the first choice of germplasm curator, geneticist, breeder and physiologist for conservation and crop improvement programs. A pollen palynological attributes and pollen germination study of Lilium longiflorum cv., 'Pavia' was conducted using scanning electron microscope (SEM). Various morphological characteristics were studied. The results showed that pollens were much alike in ultra-morphology with elliptical to ellipsoidal shape, reticulate exine and single germination ditch. The pollen viability was tested by the wet room method with 3 dyes; Acetocarmine, TTC, Lugol's iodine and 49.66% pollen viability was recorded with Acetocarmine dye; which suggested acetocarmine stain can be as a quick test method for pollen viability. The pollen germination ability was examined at set intervals, thereby establishing the dynamics of this process for 72 hours. Pollens collected just 1 h after anthesis were recorded with highest germination (85%) compared to pollen harvested before or one day after. The suitable medium for pollen germination was 3% sucrose and 15% PEG that recorded with highest pollen germination (95%) after 72 h of inoculation. Understanding evolutionary ecology and the sterility problem and designing hybridization programmes in cross-breeding necessitates a thorough understanding of pollen morphology and viability. Pollen ultra-morphology traits could be helpful in determining the evolutionary relationship of lilies.