In vitro pollen germination and tube growth of some European chestnut genotypes (Castanea sativa Mill.)

Introduction. Investigation of pollen performance is essential in breeding experiments or artificial pollination procedures, especially in a crop such as chestnut, some genotypes of which are characterized by male sterility. Our study was carried out to determine the pollen germination rate and the pollen tube growth of some European chestnut genotypes. Materials and methods. Seven Turkish advanced chestnut selections (SE3-12, SE18-2, SE21-2, SE21-9, 552-8, 552-10 and 554-14), and a cultivar (Sariaslama), growing in two different locations, were studied in the central Black Sea region of Turkey in 2006. For this purpose, in vitro pollen germination tests were performed on media with four different concentrations of sucrose [( 0, 5, 10 and 15)%]. Results and discussion. The pollen germination rates of the eight genotypes studied were significantly different due to the sucrose concentrations. The best pollen germination rate was found in the 554-14 chestnut genotype (35.80%). The best sucrose concentration for a high germination rate and pollen tube growth was 10%. For the same genotype, the results varied due to the two different study locations (Terme and Fatsa). A linear relationship between the sucrose concentrations and pollen tube length was found to be significant in most genotypes. The longest pollen tube length was found in the 554-14 genotype (74 mu m).