The present investigation was conducted at the Fruit Research Farm located in Himachal Pradesh, to assess the pollen morphology, viability and hybridization potential of seven commercially important guava (Psidium guajava L.) cultivars, namely Arka Amulya, Allahabad Safeda, Shweta, Lucknow-49, Hisar Surkha, Lalit and Hisar Safeda. The study aimed to characterize the pollen attributes of genetically distinct genotypes and evaluate their cross-pollination potential in relation to fruit set. Pollen viability was assessed using a 2% acetocarmine staining method, varied between 84.83% and 96.27%, with 'Lalit' exhibiting the highest viability (96.27%) and 'Allahabad Safeda' the lowest (84.83%). These differences in viability are likely influenced by inherent genetic variation, cultivar-specific traits, and environmental conditions such as temperature and precipitation. Microscopic examination revealed consistently rounded triangular pollen morphology across all genotypes. Controlled hybridization trials involving ten distinct cross combinations indicated that the highest fruit set (68.33%) occurred in the 'Allahabad Safeda × Lalit' cross. Variability in fruit set percentages among the crosses may be attributed to differences in genotype compatibility, pollen viability, pollen tube growth dynamics and ambient environmental conditions during anthesis. The findings underscore the significance of pollen biology in identifying compatible parental combinations, thereby aiding guava breeding strategies aimed at improving fruit set and cultivar development

Guava, Pollen, Viability, Morphology, Acetocarmine, Hybridization, Cultivars

The present investigation on pollen morphology, viability and hybridization potential of seven guava (Psidium guajava L.) cultivars provides meaningful insights into the reproductive biology of this economically important fruit crop. Significant variations were observed in pollen viability among cultivars, with 'Lalit' exhibiting the highest viability, making it a promising pollen donor for breeding programs. All cultivars demonstrated consistent rounded triangular pollen morphology, though pollen size varied notably across genotypes. These morphological and viability traits are crucial for understanding the compatibility and fertilization efficiency among different guava cultivars. Hybridization studies revealed substantial differences in fruit set percentages across ten cross combinations. The cross 'Allahabad Safeda × Lalit' showed the highest fruit set, indicating a high degree of compatibility and hybrid vigor between these two cultivars. In contrast, combinations involving 'Arka Amulya' as the female parent exhibited poor fruit set, suggesting possible cross incompatibility or less favorable environmental-genetic interactions. Such variability underscores the importance of selecting compatible parent genotypes and optimizing environmental conditions for successful hybridization and fruit development. Overall, this study highlights the relevance of palynological traits and controlled pollination strategies in guava improvement programs. Understanding pollen behavior, viability under storage, and cross compatibility can guide breeders in developing superior guava hybrids with enhanced fruit set, size, and nutritional quality. The findings not only support strategic parent selection in breeding programs but also provide a foundation for future research aimed at improving reproductive efficiency and yield potential in guava under diverse agro-climatic conditions

Lakesh Rahi, Himanshu Mehta, Vikas Kumar Sharma, Shivali, Ritik and Rashmi Thakur (2025). Studies on Pollen Morphology and Crossing Behavior of Guava (Psidium guajava L.) Cultivars in the Subtropics of North-West Himalayas. Biological Forum, 17(5a): 111-115.