2019 ASHS Annual Conference

Arum palaestinum (Black Calla Lily) is one of about 26 species of the Arum genus belonging to Araceae and used in folk medicine to cure several chronic diseases such as stomach acidity, atherosclerosis, cancer, diabetes and food toxicity. Climatic changes, water shortage, salinilty, drought and destrfications are major problems affecting native plant genetic resources in arid and semiarid regions of the world. In this research, ecophysiological investigations have been done for a better understanding of Black Calla Lilly seed germination under normal and saline conditions as well as testing its drought and salinity tolerance during establishment and growth. Seeds of Arum palaestinum were collected from their growing habitats in Bargash protected area, Irbid, Jordan during the spring of 2015.Germination trials were performed under normal and saline conditions and resulted seedling were used for drought and salinity tolerance investigations. Water regimes tested included control (100% of the total evapotranspiration), as well as 75%, 50% and 25% of the total ET. Salinity treatments were control (Tap water), EC = 5, EC = 15 and EC = 25 dS m^–1. Results indicated that 30 mM thiourea, 0.01 mM fusicoccin, 10.0 mM ethephon, and 1.5mM kinetin increased seed germination percentage and speed of Arum palaestinum under saline conditions. Ethephon was the most effective growth regulator in ameliorating salinity effect on Arum palaestinum seed germination followed by kinetin, thiourea, and fusicoccin. There was no obvious drought symptoms at the level of 75% of the total evapotranspiration. In response to the level of 50% of the total evapotranspiration, Arum palaestinum exhibited reduction in leaf characteristics, plant height, flowering characteristics, overall plant quality (attractiveness), TNC, and ET rate, and increased shoot total reducing sugars and proline content. As salinity increased, Arum palaestinum exhibited reduction in leaf characteristics, plant height, TNC, and K⁺/Na⁺ ratio, and increased shoot total reducing sugars and proline content. All tested plants were affected at different levels at EC of 15 dS m^–1 but all of them could not tolerate the EC of 25 dS m^–1. Proline accumulation could add to the drought and salinity tolerance through osmoregulation or by acting as carbon and nitrogen sink for stress recovery.