Reproductive behaviour of six olive cultivars as pollenizer of the self-incompatible olive cultivar Meski

Abstract

The cultivar Meski is one of the most widely planted olive cultivars in Tunisia. However, because of self-incompatibility, cross pollination is needed. Understanding of the correlation between the phenological stages and flower development can be helpful in choosing the right time for pollination in selecting suitable pollenizers for the Meski cultivar. In this work, floral biology in relation to phenological stages of six olive cultivars was studied to obtain a comprehensive description of suitable pollenizers for 'Meski'. The level of flowering, pistillate inflorescences, viability and germination rates of pollen grains were determined for each cultivar. The flowering period of the six tested cultivars was recorded in order to determine if their flowering duration coincides fully with the bloom period of 'Meski'. Viability, germination and pollen tube elongation abilities of all the cultivars were tested. Comparison of pollen viability of all the cultivars was done using acetocarmin staining technique and the fluorescein diacetate test. The pollen showed little loss in viability and germinability over the tested storage period at -18°C. The productive characters of six olive cultivars showed a good productive behaviour of Besbessi, Picholine, Zarrazi, Arbequina and Ascolana cultivars with particular interest for 'Zarrazi' and 'Besbessi'. Regarding pollen characteristics, 'Zarrazi' and 'Besbessi' reflected better pollen quality while the evaluation of flower quality and bloom showed good performance in all cultivars except for 'Manzanille'.