Pollen Performance and Morphology of Black Mulberry (Morus nigra L.) Genotypes

Objective: It was aimed to determine the morphology, viability, germination rates, and production quantity of black mulberry (Morus nigra L.) pollens, which play an important role in pollination and fertilization. Materials and Methods: In this research, pollen viability of black mulberry pollens using the TTC method, pollen germination test using the “agar–plate” method, pollen quantity using the Hemocytometric method, pollen sizes and morphologies using light microscope and scanning electron microscope (SEM) were examined. Results: In this study, pollen performance and morphological structures of two different dioic male black mulberry genotypes (Genotype 28 and Genotype 5) were investigated. Number of pollen grains per anther was determined as 51666 in Genotype 28 and 54666 in Genotype 5. Pollen viability ratios were 90.4% in Genotype 28 and 89.2% in Genotype 5. Pollen germination ratios of Genotype 28 and Genotype 5 were 68.7% and 72.9% respectively. Pollen shape was spherical and surface ornamentation consisted of small coarse spiny structures and irregular reticulate folds. Polar axis length was measured as 22.08 µm in Genotype 5 and 22.24 µm in Genotype 28. Equatorial axis length was measured as 21.09 µm in Genotype 5 and 21.32 µm in Genotype 28. Pollen germination apertures were evenly distributed on pollen surface, number of apertures varied and apertures were porate (spherical) type. Conclusion: Present findings revealed that black mulberry genotypes produced plenty of pollen grains, about 90% of produced pollen grains were viable and had a high germination ratio. Such findings indicated that a problem will not be encountered in terms of pollen performance in hybridization studies.