Simple cryopreservation protocol for Luffa pollen: enhancing breeding efficiency

Abstract

This study aimed to develop a long-term pollen storage protocol for <i>Luffa</i> species (<i>L. acutangula</i>, <i>L. cylindrica</i>, <i>L. echinata</i>, and <i>L. graveolens</i>) and assess its potential for crop improvement. The optimal medium for <i>in vitro</i> pollen germination varied by species, with Brewbaker and Kwack (BK) medium with 10% sucrose suitable for <i>L. acutangula, L. cylindrica</i>, and <i>L. echinata</i>, and BK medium with 3% sucrose ideal for <i>L. graveolens</i>. Overestimation in staining tests compared to <i>in vitro</i> pollen germination was observed. The best results for cryopreservation were achieved with desiccation periods of 20, 30, and 40 min, maintaining moisture content between 14.04% and 18.55%. Pollen viability was negatively correlated with storage temperature (25, 4, and -20°C) and duration. Cryopreserved pollen at -196°C exhibited the highest viability over a prolonged period (2 months) and was comparable to fresh pollen in terms of germination, ovule fertilization, and fruit and seed set. This study presents a simple and reproducible pollen cryopreservation protocol applicable across <i>Luffa</i> species, facilitating long-term storage and its use in crop improvement efforts.