Evaluating rice for salinity using pot-culture provides a systematic tolerance assessment at the seedling stage

Abstract

Background Rice ( Oryza sativa L .) is one of the major staple food crops consumed globally. However, rice production is severely affected by high salinity levels, particularly at the seedling stage. A good solution would be the development of an efficient screening methodology to identify genotypes possessing genes for salt tolerance. Result A new salinity tolerance screening technique using rice seedlings in pot-culture was tested. This method controls soil heterogeneity by using pure sand as a growth medium and minimizes unexpected extreme weather conditions with a movable shelter. Seventy-four rice genotypes were screened at three salinity treatments including high salt stress (electrical conductivity (EC) 12 dSm − 1 ), moderate salt stress (EC 6 dSm − 1 ), and control (no salt stress), imposed 1 week after emergence. Several shoot and root morpho-physiological traits were measured at 37 days after sowing. A wide range of variability was observed among genotypes for measured traits with root traits being identified as the best descriptors for tolerance to salt stress conditions. Salt stress response indices (SSRI) were used to classify the 74 rice genotypes; 7 genotypes (9.46%) were identified as salt sensitive, 27 (36.48%) each as low and moderately salt tolerant, and 13 (17.57%) as highly salt tolerant. Genotypes FED 473 and IR85427 were identified as the most salt tolerant and salt sensitive, respectively. These results were further confirmed by principal component analysis (PCA) for accuracy and reliability. Conclusion Although tolerant genotypes still need to be confirmed in field studies and tolerance mechanisms identified at the molecular level, information gained from this study could help rice breeders and other scientists to accelerate breeding by selecting appropriate donor parents, progenies and potential genotypes at early growth stages necessary for salinity tolerance research. Electronic supplementary material The online version of this article (10.1186/s12284-019-0317-7) contains supplementary material, which is available to authorized users.

Optimization of nitrogen fertilizer management for improving rice grain yield and nutrient accumulation and mobilization in saline‐alkaline soils

“…Screening and breeding salinity‐tolerant cultivars is crucial for rice production in saline‐alkaline soils. Generally, in rice plants growing in saline‐alkaline soils, several physiological processes such as photosynthesis, respiration, and hormonal regulation are negatively affected, and this results in unbalanced nutrient absorption and reduced crop yields (Kakar, Jumaa, Redoña, Warburton, & Reddy, 2019; Negrão, Schmöckel, & Tester, 2017). Currently, the lack of high‐yielding, salt‐tolerant rice varieties and crop management practices customized for saline‐alkaline soils is a major barrier to rice production.…”

Phenotypic response of farmer‐selected CWR‐derived rice lines to salt stress in the Mekong Delta

“…in the field (Kakar et al, 2019). Furthermore, it may not be sufficient to use shoot and root growth parameters only for the classification of breeding lines as tolerant and sensitive.…”

Screening and evaluation of reliable traits of upland cotton (Gossypium hirsutum L.) genotypes for salt tolerance at the seedling growth stage

“…It is also helpful to provide an additional benefit towards understanding the underlying physiology and genetic mechanisms of tolerance at sensitive stages of plant growth (Ismail and Horie 2017). The correct phenotypic evaluation of genotypes is significant for salinity tolerance based on genetic approaches (Kakar et al 2019). Different morpho-physiological indexes are responsible for the tolerance to salt stress.…”

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