Determination of pollen viability and germination in banana (Musa acuminata) diploids under humid tropical conditions

Genetic improvement of banana ( Musa acuminata ) is essential to overcome the challenges that limit its sustainable production, including critical diseases such as Fusarium tropical race 4 (Foc TR4) and Black Sigatoka caused by Pseudocercospora fijiensis . This study aimed to evaluate the viability and germination of pollen from three improved diploids Musa acuminata (accessions M53, 013018-01, and 013004-04), along with a globally recognized wild accession 'Calcutta 4' and a non-fertile commercial cultivar M. acuminata cv. Pisang Mas as a contrasting treatment, under humid tropical conditions in Turrialba, Costa Rica. Pollen grains were collected at different times (7:30, 10:30, and 13:30) and from different positions of the male inflorescence (proximal, medial, and distal). Results showed significant differences in pollen germination based on genotype, sampling time, and position. The diploid M53 had the highest germination percentage (21.2 %), with distal positions and afternoon sampling being the most favorable, followed by diploids 013018-01, Calcutta 4, and 013004-04 with germination rates of 16 %, 8 %, and 5 %, respectively. All genotypes exhibited viability percentages above 90 %. The cultivar Pisang Mas showed no germination in any of the evaluated treatments due to its sterility. These findings provide important insights for genetic improvement programs, facilitating the selection of progenitors with better reproductive capacities under tropical conditions and strengthening the genetic base for research with Cavendish subgroup representatives to address current biotic and abiotic threats.