Evaluation of Morphological Characteristics, Yield Components and Catalase Enzymes Activity of Lallemantia royleana Benth. under Drought Stress

Lallemantia royleana (Walla) Benth is a folk medicinal plant of Labiatae family. This family is one of the largest and most distinctive flowering plants, with about 220 genera and almost 4000 species worldwide. It is well represented in different regions of European and the Middle Eastern countries especially Iran by 46 genera and 410 species and subspecies. The vernacular name of L. royleana’s seed in Iran is Balangu or Balangu Shirazi. Balangu seed is a good source of carbohydrates (45.25%), crude fiber (30.67%), ash (3.63%), oil (18.27%) and protein (25.60%) and has some medicinal, nutritional and human health properties. Balangu seed that conventionally consumes as stimulant, constituent, diuretic, and expectorant, is used in a range of products made in traditional or industrial applications such as beverage (namely Tokhme Sharbati) and bread in Iran and Turkey. Drought stress is one of the most important abiotic factors which adversely affect growth, metabolism, and yield of crops in semiarid and arid area. Drought stress during any particular growth stage of crops causes yield reduction. The purpose of this test is to evaluate the effect of drought on morphological characteristics, yield components and catalase enzymes activity of medicinal plant population are Balangu.

To evaluate the effect of drought stress on morphological characteristics, yield components and catalase enzymes activity of medicinal plant populations Balangu split-plot experiment in randomized complete block design with three replications in research farm of the  Shahed University of medicinal plants in the year 2015. Factors examined include three levels of drought at flowering stage as the main factor (soil water potential of -0.5 atmosphere as a witness, 6.5- and 9.5- atmosphere), 5 Balangu population includes a population of Kurdistan (Sanandaj) Province and 4 population of Isfahan Province (E3 (Naein), E5 (Ardestan), E6 (Najaf Abad), E7 (Khansar)) were considered as subplots. Measured traits including root length, plant height, fresh and dry weight per plant, grain yield, components grain yield, mucilage percent, and yield. In order to study morphological traits, seven plants of each plot were selected with due consideration of margins. To determine yield components are calculated, about four square meters per plot was harvested at maturity. The ROS scavengers are antioxidant enzymes containing catalase. Information obtained through the statistical program SAS 9.12 for analysis and the means were compared by Duncan's multiple range test in 5% level.

The results showed significant effect of drought on morphological traits, yield components (except the number of nut in every cycle) and catalase enzymes activity. With increasing drought traits such as plant height and its components declined. Balangu populations on plant height, number of tributaries, fresh and dry weight per plant was non-significant. In the crowd, except root length in the rest statistically significant differences were observed. For the purpose of planting the seed Balangu, E3 has the potential moisture in the atmosphere -.9.5 atm had the highest grain yield per plant. A significant positive correlation with yield and grain yield per plant, grain weight, number of cycles of flowers per plant and plant height. Pearson correlations between traits with grain yield results showed that the Grain Yield per plant and Plant height (r=0.580**), thousand grain weight (r=0.514**),  nut number of per flowers cycle (r=0.496**),  fresh weight per plant (r=0.360**), dry weight plant (r=0.337*), and root length (r=0.324**) positive correlation and significant and flowering cycle her plant (r=-0.299*) showed a significant negative correlation and significant. No significant grain yield with other traits.

The results of this study indicated that drought stress at flowering stage increased root length and catalase enzyme as well as decreased other morphological traits, grain yield components, percentage and mucilage yield and protein content of balangu medicinal plant. In moderately severe stress, the highest grain yield and mucilage yield were related to Nain population, and in mild stress, Ardestan (E5) population had the highest grain yield, percent and mucilage yield. Therefore, considering the stresses introduced, introducing high-yielding populations in relatively severe stresses can lead to water use efficiency and irrigation management. Due to the necessity of production of medicinal plants in crop systems and the necessity to pay attention to cultivation of these plants in arid and semi-arid regions, it is recommended in severe climatic conditions of Naein (E3) population under similar climatic conditions.