A review on effects of facilitators in seed germination of range species in ecological zones of Iran

The growth facilitators are used to improve plant germination rate, and growth can increase rangeland restoration's success in dry regions. This study reviewed articles that were published in scientific databases from 1998 to 2022 and the number of each facilitator in the ecological zones of Iran (Caspian or Hircanian, Iran-o-Tourani, Khalij-o-Omanian, and Zagros) was filtered and displayed in charts. Most publications were related to the use of all facilitators in the Iran-o-Tourani region (Organic or biological matters: 35, Hydrogel:30, Nanoparticles:24, Animal manure:15, Seed Humic acid:12, Compost:12, priming:11). This result can be considered as the need to seed planting of rangeland species in the Iran-o-Tourani region to prevent further destruction of rangelands, increase fodder for livestock, and prevent desertification and fine dust. The lowest number of publications was related to the Zagros and Khalij-o-Omanian ecological zones due to humidity and much precipitation. The results showed that nanoparticles, organic and biological materials and hydrogels have been used the most in all ecological zones due to their lowest environmental risks and the highest efficiency in increasing the yield of plants.