Pollen germination and behavior in different lemon cultivars

F. Córdoba López, M. Moreno Verdú, M. Rabadán Mínguez, C. Rodríguez Sánchez, M. Pérez-Jiménez, O. Pérez-Tornero
Characterizing pollen performance is especially relevant for some economically significant species of Citrus. However, little is known about self- or cross-incompatibility in lemon, which are very important traits for breeding in this Citrus species. In this study, pollen-pistil interactions were characterized in five lemon cultivars (‘Fino 49’, ‘Verna 51’, ‘Fino 95’, ‘Eureka’ and ‘Lisbon’) in multiple experiments. First, in vitro germination at five temperatures (10, 15, 20, 25 and 30°C) as well as a pollen viability analysis were carried out. Then, to check self- or cross-compatibility and characterize the influence of the pistil genotype, self- and cross-pollination among the lemon cultivars was performed. Although pollen viability was high in all of the cultivars, germination was strongly affected by temperature. Very low germination was obtained at the lowest temperature (10°C), and pollen showed its maximum germination percentage at 25°C. These results were verified by the self- and cross-pollination experiments in the field, where the number of pollen grains germinating on the stigma increased with time from pollination. Nine days after pollination, under field conditions, pollen tubes reached the base of the style in most combinations, except for self-pollinated ‘Fino 95’. Altogether, pollen tube growth in the style was faster after cross-pollination. Pollen tubes inside the ovary were observed starting on the sixth day and reached their maximum length on the twelfth day in all of the treatments. ‘Lisbon’ and ‘Fino 95’ had the highest number of pollen tubes in the ovary following self-pollination, while ‘Fino 49’בFino 95’, ‘Fino 95’בFino 49’, and ‘Fino 49’בEureka’ were the cross-pollination treatments with the maximum number of pollen tubes in the ovary.
Córdoba López, F., Moreno Verdú, M., Rabadán Mínguez, M., Rodríguez Sánchez, C., Pérez-Jiménez, M. and Pérez-Tornero, O. (2023). Pollen germination and behavior in different lemon cultivars. Acta Hortic. 1362, 605-612
DOI: 10.17660/ActaHortic.2023.1362.82
Citrus limon, compatibility, ovary, pollen tube, pistil, temperature

Acta Horticulturae