Responses of Dragon’s Head (Lallemantia iberica) and Lady’s Mantle (Lallemantia royleana) Inoculated by Mycorrhiza to Different Irrigation Regimes

In natural environments, plants are continuously exposed to diverse environmental conditions that may affect plant survival, development and production. Water deficiency considers as one of the most ominous abiotic factors that limits the growth and yield of crops and decreases water use efficiency and photosynthesis rate. Nowadays it is suggested to use bio-fertilizers as a tool to adjust adverse effects of water shortage in soil. Bio-fertilizers containing Arbuscular mycorrhizal fungi are supposed to use. Some plant species have the ability to form a symbiosis relationship with the Arbuscular mycorrhizal fungi (AMF). AMF can increase growth and yield of plants under water deficiency, and it is one of the most important bio-inoculant that can be used to adjust adverse effects of water stress in plants. AMF-symbiosis considerably increases root colonization which turns into improving water use efficiency. Also, it establishes a platform to increase phosphorus mobility between soil and roots in the rhizosphere. Lallemantia iberica (Dragon’s head) and Lallemantia royleana (Lady’s mantle) are medicinal plants that belong to the Lamiaceae family. Genus Lallemantia seeds contain mucilage, polysaccharide, fiber, oil, protein, and plenty of valuable secondary metabolites. Limited information is availiable about the ability of these two species to make symbiosis relation with AMF under water deficit condition.  Hence, the current study was aimed to evaluate of Lallemantia iberica and Lallemantia royleana inoculated by mycorrhizal in the different irrigation regimes.

The field trial was conducted at the Research Farm of the Agricultural Faculty of Shahed University, Tehran, during the cropping season of 2018 and 2019. A split-factorial experiment was employed in a randomized complete block design (RCBD) with three replications. The main plot consisted of three-level of irrigation regimes (30% (I30; without stress), 60% (I60; mild stress), and 90% (I90; sever stress) depletion of available water resource). The sub plots were factorial combination mycorrhizae (non-inoculation and inoculation of mycorrhizae) and plant species of Lallemantia (L.iberica and L. royleana). 

Increasing water deficit significantly reduced plant height, grain yield, chlorophyll a and b, water use efficiency, root colonization, seed phosphorus, seed mucilage, and seed oil content However, the highest plant height, grain yield, chlorophyll a and b, water use efficiency, root colonization, seed phosphorus, mucilage, and oil seed content obtained at 60% available water soil of depletion (mild stress). The application of mycorrhizae increased plant height, grain yield, chlorophyll a and b, water use efficiency, root colonization, seed phosphorus, seed mucilage, and oil seed content in cross all irrigation regimes. It has been reported that establishment a relationship of symbiotic AMF with roots of host plant, through spreading the hyphae and developing the root system, improves growth and provides more water for plants, which finally this ability leads to the yield, root colonization and water use efficiency. Inoculated and non-inoculated L .royleana had the greatest resistance to different levels of irrigation regimes and mycorrhizal treatments than L. iberica. It has been reported that L. royleana was more tolerant to water deficit in compared to L. iberica  Also the results showed that the highest root colonization was in L. royleana species which was grown under different levels of irrigation regimes and mycorrhizal treatments.

In general in this research, it can be concluded that under water deficit stress conditions, water deficit stress damages can be reduced in both species of Lallemantia with careful irrigation management (using an irrigation regime of 60% available water soil of depletion) and application of mycorrhizae.