Protocol for Screening for Salt Tolerance in Rice

Abstract

A simple protocol is presented that tests salt tolerance in rice seedlings. The method is based on a glasshouse hydroponics test in which salt is added to the nutrient hydroponic solution in which the seedlings are grown. A list of equipment is provided including hydroponic hardware and stock solutions. Advice is given on seed storage prior to use and pregermination treatments that promote even germination of test samples. Salt treatments commence after seedling establishment in hydroponics, at the 2-3 leaf stage. Information on responses of standard genotypes (tolerant, intermediate and sensitive) is given to which test seedlings are compared. Visual symptoms of salinity stress include reduced leaf area, whitish appearance of lower leaves, leaf tip death, leaf rolling and seedling death. Scoring is carried out according to the standard evaluation system developed by the International Rice Research Institute (IRRI). Recommended test salt concentrations are given along with a method to recover selected seedlings and examples of use. 4.1 Introduction Rice is one of the most important crops and is consumed by more than half of the world's population. Soil salinity is a major and increasing problem limiting rice growth and leads to huge yield losses every year. The search for new cultivars with improved tolerance to salt stress is a major goal in relieving this problem. This protocol gives an easy-to-follow procedure to select salt-tolerant rice lines for subsequent field testing. 4.2 Equipment All equipment (tanks, trays, containers, drums and platforms) is dark coloured to minimise light penetration into the culture solution, thus reducing algal growth.

Trichoderma Enhances Net Photosynthesis, Water Use Efficiency, and Growth of Wheat (Triticum aestivum L.) under Salt Stress

“…The coated seeds were placed onto two layers of moistened filter paper in Petri plates. After one week, 30 (15 for each cultivar) uniformly emerged wheat seedlings were transferred to hydroponic vessels containing Hoagland solution under aerated conditions [ 57 ]. The seedlings were grown hydroponically for 14 days and exposed to either 0 mM NaCl or 200 mM NaCl.…”

Seedling‐stage salinity tolerance in rice: Decoding the role of transcription factors

“…Whereas some high-yielding and improved varieties like IR29, IR64, and Sarjoo 52 are highly sensitive to salinity stress (Krishnamurthy et al, 2020;Rahman et al, 2016). Several phenotyping protocols were developed to screen seedlings for salt tolerance in rice, wheat, and barley; tolerance is determined by performance morphological comparisons against known salttolerant genotypes (Bado et al, 2016). In recent years, comparative analysis of contrasting genotypes has proven an efficacious approach for finding genes associated with plant salinity tolerance (Kumari, Nee Sabharwal, et al, 2009;Soda et al, 2013;Yadav et al, 2022).…”

A Model to Incorporate the bHLH Transcription Factor OsIRO3 within the Rice Iron Homeostasis Regulatory Network

“…For the alkalinity stress experiment, rice plants were exposed to four days of nutrient-sufficient conditions, seven days of either alkalinity stress (14 mM Na 2 CO 3 ) or control (0 mM Na 2 CO 3 ) conditions, and a five day recovery period of nutrient-sufficient (0 mM Na 2 CO 3 ) conditions, as previously described [38]. Following the recovery period, shoot and root tissues were harvested separately, and alkalinity tolerance was assessed phenotypically based on criteria previously described [43].…”