Micro-morphological characterisation of date palm (Phoenix datylifera L.) pollen and study of the effect of temperature on their germination in vitro

¹ Laboratory for Improvement of Agricultural Production, Biotechnology and Environment, Department of Biology, Faculty of Sciences of Oujda Mohamed First University, BP524, 60 000 Oujda, Morocco.
² Laboratory of Bioresources, Biotechnologies, Ethnopharmacology and Health, Department of Biology, Faculty of Sciences of Oujda Mohamed First University, BP524, 60000 Oujda, Morocco.
³ Higher School of Education and Training, Mohammed First University, Oujda, Morocco.
⁴ Sultan Moulay Slimane University of Beni Mellal, Multidisciplinary Res. & Innovation Laboratory / Natural Resource Engineering and Environmental Impacts Team, Polydisciplinary Faculty of Khouribga BP 145, Khouribga, Morocco
⁵ Biotechnology, Environmental Technology and Valorization of Bio-resources team, Department of Biology, Faculty of Science and Technology Al-Hoceima, Abdelmalek Essaadi Univ., Morocco

^* Corresponding author: Anass.alla@ump.ac.ma

Abstract

The date palm (Phoenix dactylifera L.) is a dioecious monocotyledonous plant belonging to the Arecaceae family. The pollen grains of different male date palms exhibit distinct characteristics that influence their pollination potential. This study aims to select high-performing males and determine the optimal temperature for pollen grain germination. Seven male pollinators GP1 to GP7 were selected based on the evaluations of the date palm farmers in the Figuig oasis. The micromorphological parameters and the viability of the pollen grains were determined in vitro. At the turgescence stage of the pollen grains, a significant difference was detected regarding their diameters with maximum and minimum values ranging between 36.4 and 27.6 μm respectively for GP4 and GP6. Regarding the study of pollen grain germination, three incubation temperatures were tested: 25°C, 27°C, and 30°C. The temperatures of 27°C and 30°C were considered the most favorable for germination. All temperatures included, the types GP1, GP6, and GP3 exhibited the highest germination rates.