Responses of dragon head (Lallemantia iberica) and Lady’s mantle (Lallemantia royleana) to nano-iron chelate under different irrigation regimes

Water deficit is as one of the most ominous abiotic factors that limits the growth and yield of crops and reduced photosynthesis content (Askary et al., 2017). The common symptoms determined in plants after encountering water deficit include a hindrance to growth, a reduction in the rate of photosynthesis, an acceleration oxidative stress (Aalipour et al., 2020). A balanced nutrient concentration in the soil is known as another essential element for plant growth regulation (Taghizadeh et al. 2019). This can be supplied by the application of chemical fertilizers (nano iron chelate). Nano iron chelate fertilizer can also protect plants against water deficit stresses and improves photosynthesis and assimilates transportation to sinks and eventually amends grain yield and oil content (Moradbeygi et al., 2020). The aim of this study was to investigate the response of Dragon head (Lalelemantia iberica) and Lady's mantle (Lalelemantia royleana) to the application of nano-chelate fertilizer in 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 regime (30% (I30; without stress), 60% (I60; mild stress), and 90% (I90; sever stress) depletion of available water resource). The sub plots were factorial combination nano-iron chelate (without fertilizer and nano-iron chelate) and plant species of Lallemantia (L.iberica and L. royleana).

By increasing water deficit reduced, chlorophyll a and b, CAT and APXs enzyme activity, plant height, root length, seed yield, content of mucilage and oil. The reduction of plant growth parameters and seed yield of both species Lallemantia may be due to extended irrigation intervals which caused decline in Chl concentration, stomata closure, and decreased CO2 uptake for photosynthesis (Paravar et al., 2021). Our results showed that the highest chlorophyll a and b, CAT and APXs enzyme activity, plant height, root length, seed yield, content of mucilage and oil was obtained at 60% available water soil of depletion (moderate drought stress). The application nano-iron chelate in all cases mitigated the negative effects of water deficit stress on chlorophyll a and b, CAT and APXs enzyme activity, plant height, root length, seed yield, content of mucilage and oil. Increasing in growth parameters and seed yield under drought stress of Lallemantia species under application of nano-iron chelate condition in drought stress may be due to the role of iron the chlorophyll structure and plant photosynthesis system (Moradbeygi et al., 2020). Indeed application of nano-iron chelate by photosynthesis improvement and material production in the plant causes the increasing growth and yield. (Iqbal and Umar, 2019). In addition, in this study observed nano-iron chalet application played the important role on the increasing of CAT and APXs enzyme activity under drought stress. It has been reported that micronutrients such as iron has a structural role in some enzyme such as CAT and APXs (Moradbeygi et al., 2020). Higher seed yield and seed oil  L.iberica than L.royleana  under application nano-iron chelate and different levels of irrigation regimes may be due to the increasing chlorophyll a and b (Paravar et al., 2022). Compared with L.iberica, the greater CAT and APXs enzyme activity in L.royleana is probably due to the mucilage around roots of L.royleana that has caused the reduction of oxidative stress (Paravar et al., 2021).

Therefore, in general in this research, it can be concluded that under water deficit stress conditions, we can reduce damages from water deficit stress in both species of Lallemantia with careful irrigation management (using an irrigation regime of 60% available water soil of depletion) and application nano-iro chelate.