Growth, photosynthesis and pollen performance in saline water treated olive plants under high temperature

• Main Authors: Georgios C. Koubouris, Nikolaos Tzortzakis, Nektarios N. Kourgialas, Marina Darioti, Ioannis Metzidakis
• Format: Article
• Language: English
• Published: PAGEPress Publications 2015-10-01
• Series: International Journal of Plant Biology
• Subjects: Olea europaea L.; photosynthesis; pollen germination; salinity
• Online Access: http://www.pagepress.org/journals/index.php/pb/article/view/6038

Olive cultivation in hot arid areas is hindered by the scarcity of irrigation water. The exploitation of saline water has been proposed as a solution to partially cover plant water demands. This paper presents the effects of salinity [0, 60 and 120 mM sodium chloride (NaCl)] on physiological and reproductive functions of cultivars <em>Koroneiki</em> and <em>Amphissis</em> in a closed hydroponic system. Shoot growth was markedly reduced in high salinity dose in <em>Amphissis</em> (−81%) and <em>Koroneiki</em> (−75%). The photosynthetic rate was significantly reduced at 120 mM NaCl for both cultivars, as well as chlorophyll and carotenoids content (43% and 44%, respectively). The Na+ content in all plant parts increased in both salinity doses especially in <em>Amphissis</em> while K concentration decreased for both cultivars. Inflorescences in <em>Amphissis</em> were severely damaged due to salinity. Consequently, pollen sampling and <em>in vitro</em> germination study was only feasible for <em>Koroneiki</em>. Indeed, <em>Koroneiki</em> pollen germination was reduced at 60 mM NaCl (−42%) and at 120 mM NaCl (−88%). Pollen tube length was also reduced by 15% and 28% for the middle and high salinity dose, respectively. The results of the present study indicate that <em>Amphissis</em> is more sensitive in high salinity doses compared to <em>Koroneiki</em> and that reproductive functions are severely affected by salinity.