Assessment of Pollen Quality and Germination Dynamics in Chestnut (Castanea spp.): Implications of Genotypic Variation and Sucrose Concentration

Abstract

Pollen viability and germination are critical factors influencing reproductive success and nut yield in chestnuts (Castanea spp.). However, their dynamics across different genotypes and cultivars remain insufficient. This study aimed to assess the pollen quality of seven chestnut genotypes/cultivars (‘Akyüz,’ ‘Ali Nihat,’ ‘Macit 55,’ A55, A56, ‘Marigoule,’ and BDB-L) grown in Samsun, Türkiye. Pollen viability and germination rates were evaluated across four sucrose concentrations (0%, 5%, 10%, and 15%). The results showed significant genotypic differences in pollen quality. The BDB-L genotype consistently exhibited the highest viable pollen percentages (38.48% in 2022 and 40.99% in 2023) and germination rates, peaking at 43.73% in 2023 at 10% sucrose. Similarly, the ‘Akyüz’ cultivar demonstrated robust performance with viable pollen percentages exceeding 38% across both years and germination rates reaching 40.30% at 5% sucrose. Conversely, A55 and A56 genotypes showed significantly lower pollen viability and germination rates. They also showed the highest non-viable pollen percentages and minimal germination across all sucrose concentrations. The optimal sucrose concentration for pollen germination was determined to be 10% for most genotype/cultivars. These findings underscore the critical influence of genotype and sucrose concentration on pollen quality, providing practical insights for breeding programs and orchard management strategies. The superior performance of the BDB-L genotype and ‘Akyüz’ cultivar highlights their potential as reliable pollinizers, while the weaker performance of A55 and A56 suggests the need for targeted research to improve their reproductive traits. Future studies should explore the genetic and environmental factors affecting pollen quality to enhance the reproductive success and yield potential of chestnut cultivars.