Screening and Identification of Salt Tolerance Rice (Oryza sativa. L.) Genotypes at Early Seedling Stage

Abstract

Crop yield lose due to soil salinization is an increasing threat to agriculture worldwide. An efficient and yield based techniques for selection of salt tolerant lines has been developed under the three different levels of salinity stress such as T₁ = 00, T₂ = 6 and T₃ = 8 dS m^-1 NaCl in green house. The current study was conducted in control condition where initially nutritional supplements were used as Hoagland solution (Hoagland solution is a hydroponic nutrient solution, which provide every essential nutrients for plant growth). The mentioned research was observed in the experimental site of Nuclear Institute of Agriculture (NIA) Tandojam to assess the response of coded as well as local cultivated lines under the salinity stress. 21 days old seedlings were transplanted at culture solution area at three different levels of sodium chloride. Twenty different lines were grown and compared with each other for morpho-physilogical and yield based traits. The results exposed considerable variations among shoot length, root length, root weight, shoot weight, leaf area and chlorophyll content at different stress of NaCl. The result regarding stress observed that, genotypes GML-529, IR-72 and KANGNI-27 showed more than 50 % reduction in shoot length during stress, while genotypes IR-83, HHZ SAL-10-DT1-DT2, and SHUA-92 showed promising results for shoot length. Physiological observation revealed that HHZ SAL-10-DT1-DT2, Kharagnjia, FL-478, IR-72, SHUA-92 and GML-498 showed higher green pigment (chlorophyll content) and leaf area, however among tested lines, KSK-282, HHZ SAL-10-DT1-DT2, DR-82, IR-8, and Basmati-515 stored higher K⁺ and lower Na⁺ in both stress condition, which favors to our target and breeding objective.). Therefore, it is proved that above mentioned lines would be found as suitable for further breeding program regarding introducing salt tolerant rice genotypes and identified genotypes shoukd be further tested at reproductive stage for yield and yield associated traits under similar stress at different locations of saline soil of Sindh, Pakistan.