Background: Water stress is one of the most important abiotic stresses, which limiting plant growth and yield in dryland conditions. Balangu (Lallemantia spp), is a plant of Lamiaceae family and has several nutritional and medicinal uses. This experiment was carried out in the farm of Yasouj Agricultural and Natural Resources Research Center in 2017-2017. This study was conducted in a randomized complete block design with five medicinal plant landraces of Balangu (Kerman, Isfahan, Kurdistan, Mashhad and Malekan) in four replications in dryland conditions. Due to water limitation in arid and semi-arid regions and the importance of the Balangu medicinal plant, the objectives of this experiment was to improvement the yield, percentage and yield of mucilage and seed oil of Balangu landraces in dryland conditions. Methods: The measured traits in this experiment included grain yield, mucilage and oil. The percentage of mucilage was measured by, heat one gram of dry grain with 10 ml of 0.1 N hydrochloric acid until discoloration occurs in the grain shell, then add 60 ml of 96% ethyl alcohol to the resulting mucilage solution and refrigerate for five hours. The resulting precipitate was placed in an oven for 12 hours after filtration at 50 C °. After the amount of mucilage was recorded as a percentage. The seed oil percentage was measured by Soxhlet method. First, the desired seeds were milled. Then passed through a 20 mesh sieve and about 5 to 10 grams of powdered seeds were wrapped in filter paper. Then, a sample of filter paper with seed powder was placed in the cartridge of Soxhlet extractor machine.
Results: The results showed that in dryland conditions, grain yield, mucilage and oil of Balangu landraces were significant at 5% probability level. The highest grain yield was obtained from Kurdistan and Mashhad landraces with average yields of 529 and 515 kg ha-1, respectively. They had higher mucilage and seed oil yield than other landraces tested.
Conclusion: Overall, the results of this study concluded that the landraces of Kurdistan and Mashhad are recommended for cultivation in dryland conditions due to high yield, mucilage and grain oil.