Drought stress can have many effects on the agronomic and physiological characteristics of plants. Corn is used in human and animal nutrition. It has 60-72% starch and 8-11% protein (Darrah et al., 2019). The high water requirement of corn is one of the most important effective factors in preventing the development of its cultivated area. Therefore, It is very important to introduce new corn hybrids that tolerate drought (Corcoles et al., 2019: Rudnick et al., 2017). Selenium is an essential and rare element, which has many effects on human health and physiological characteristics of plants (Rayman, 2017). The research results have shown that the use of selenium fertilizers is a suitable solution to increase the tolerance of plants to environmental stresses such as drought stress. This research was conducted to investigate the effect of selenium spraying on the electrical conductivity of cell sap in corn cultivars under drought stress conditions.
Materials and Methods:
This experiment was conducted in 2011 in the twice split-plot arrangement of treatment in a randomized complete block design with three replications in a training-research farm. Payam Noor University of Central Province (Arak city) was implemented. Drought stress (I0= Control irrigation, I1= Irrigation about 80% plant requirement water, I2= Irrigation about 60% of plant requirement water, were assigned in the main plots, maize cultivars (V1= KSC 500, V2= KSC 520, V3= KSC 700) in sub plots and foliar treatment of selenium in two levels (Se0= Control, Se1= 20 g ha-1) in sub-sub plots. In this study characteristics such as: ear height, panicule length, number of ear m-2, stem height, forage yield and un-stability of cell membrane were assessed.
Results and Discussion:
The results showed that the effect of water stress treatment on the traits of stem height (5%), forage yield and cell membrane instability (1%) was significant. Also, the difference of maize cultivars was significant in terms of the number of ear m-2, forage yield and cell membrane instability. The highest and lowest values of cell membrane instability with an average of 1759 and 1456 µs cm-1, respectively, belonged to the irrigation treatment based on 60% of the water requirement of the plant and the control irrigation treatment. Among the maize cultivars, the highest and lowest values of cell membrane instability with an average of 1675 and 1587 µs cm-1, belonged to KSC 700 and KSC 500, respectively. Selenium consumption had a positive effect on reducing the amount of cell membrane instability, so that the average cell membrane instability in the treatment without selenium consumption decreased from 1687 to 1601 µs cm-1, in the treatment with selenium consumption.
The results of this research showed that by changing the irrigation regime from normal conditions to irrigation based on 60% of water requirement of maize, forage yield decreased by 23.35%. The response of maize cultivars was also different in terms of forage yield, so that cultivar KSC 700 was superior to the other two cultivars. The use of 20 (g ha-1 of selenium) increased the forage yield by 64.4%.