POLLEN VIABILITY AND GERMINATION RESPONSES OF CASHEW (ANACARDIUM OCCIDENTALE L.) UNDER IN VITRO CONDITIONS

Cashew (Anacardium occidentale L.) is a vital cash crop in tropical and subtropical regions, valued for its economic significance and nutritional benefits. Pollen is crucial in plant reproduction, with viability and germination determining fertilization success. However, variations in pollen viability among cashew accessions remain understudied. Understanding genetic variability in pollen fertility will aid in selecting superior pollen donors, enhance cross-breeding efficiency, and supports the development of improved cashew cultivars for sustainable production. This study investigated pollen viability and optimized in vitro germination conditions for 18 cashew clones. The research aimed to determine the efficacy of pollen from different clones and establish optimal protocols for successful in vitro pollen germination. The findings are expected to contribute to improved cashew breeding strategies and enhanced genetic resource management. At the Cocoa Research Institute of Nigeria (CRIN), Ibadan, pollen viability was evaluated via aniline blue-lactophenol staining. In vitro pollen germination was assessed using modified Brewbaker and Kwack's (1964) media, with observations recorded after a 24-hour incubation. Pollen tube lengths were subsequently measured using ImageJ, and the resultant data were subjected to ANOVA analysis, followed by Duncan's Multiple Range Test for mean separation. Pollen viability analysis revealed significant inter-accession variation, from 56.3% to 97.2%. Accessions EU202 (97.2%) and CR102 (96.1%) demonstrated superior viability, while Brazilian Medium (56.3%) and India Madras (59.5%) exhibited comparatively poor performance. Germination rates also varied considerably, with select clones achieving complete germination in Media 2. Statistical analysis confirmed genotype-specific influences on pollen germination in response to differing media conditions.