Gomez ka 1976 laboratory manual for physiological studies of rice. Salinity is a significant constraint to rice productivity in many inland and coastal rice growing areas and, furthermore, is contributing to the loss of arable lands in many countries due. Therefore, a statistical model combining morphological and. Four simple sequence repeats ssr markers rm493, rm10793, rm3412 and rm10791 found in the saltol locus in chromosome 1 were used for molecular analysis. New phenotyping technique for salinity tolerance at reproductive stage in rice. Pdf evaluation of salinity tolerance in rice genotypes. One of the identified endophytic fungus, which was tolerant to high concentrations of salt, was transferred to the saltsensitive rice variety ir64. Pollen viability, number of unfilled and filled grain and grain yield per plant were evaluated. Genetic analysis of salinity tolerance in rice oryza sativa l.
Mapping of salt tolerance qtls in introgression lines. Employing transgenic technology, functional validation of various target genes involved in diverse processes such as signaling, transcription, ion homeostasis, antioxidant defense etc for enhanced salinity stress tolerance has been attempted in various model systems and some of them have been extended to crop plant rice too. Aris hairmansis a thesis submitted for the degree of doctor of philosophy school of agriculture, food and wine faculty of sciences the university of adelaide february 2014. The effect of salinity on dry matter production varied from cultivar to cultivar. Characterizing the saltol quantitative trait locus for.
This study was designed to identify useful agronomic. Screening rice varieties for salinity tolerance 171 table 1. Tagging and validation of ssr markers to salinity tolerance. Rice varieties mr211, ir20, br40 and mr232 showed greater salt tolerance during germination germinated at 12 ds m 1 salinity. Salinity tolerance and transcriptomics in rice university of. Significant varietal differences were found in relation to salinity tolerance. Salinity is defined as the presence of excessive amounts of soluble salts in the soil usually measured as electrical conductivity, ec. However, mr211, mr232 and ir20 performed better based on dry matter. Assessment of salt tolerance and variability within some rice. Evaluating rice for salinity using potculture provides a. Pdf salinity and salt tolerance improvements in thai rice. Moreover, exogenous asa restored the salt tolerance of osvtc ri plants, indicating that the asa synthesis in rice roots is an important factor for the response of rice to salt stress. Susceptibility or tolerance of rice plants to high salinity is a coordinated action of multiple stress responsive genes, which also interacts with other components of stress signal transduction pathways.
Pdf screening rice for salinity tolerance, vol 22, irri. Capsule provides an alternative source of salinity tolerance aside. Effect of salinity on chlorophyll concentration, leaf area, yield and yield components of rice genotypes grown under saline environment y. In woody species, high soil salinity may lead to leaf burn and defoliation. Genomewide association study of seedling stage salinity. To this end, threeleafstage rice seedlings wild type and osrr9osrr10 mutant were exposed to 150. An analysis of 100 ssr markers on 140 ir29pokkali recombinant inbred lines rils confirmed the location of the saltol qtl on chromosome 1 and identified additional qtls associated with tolerance.
Genetic variation in southern usa rice genotypes for. Investigations of the effects of salinity on rice have been underway for more than 50 years kapp, 1947. Pearson, 1959 and attempts to enhance the salt tolerance in rice through breeding date from the early 1970s akbar et al. Detailed description of rice varieties selected for the study. Effects of salinity stress on growth, chlorophyll content and. Screening rice varieties for salinity tolerance by. Na, ca, mg, cl, and so4 are the major ions involved.
Electro physiologically, increasing salinity reducedthe electrical pd of plant leaves. Salinity tolerance loci revealed in rice using high. Genetic analysis of components of salinity tolerance in rice oryzasativa l. Worldwide rice is grown on some 400 million hectares of salt affected land. The difference of electrical pd on each variety of the rice in different levels of salinity can be used as a screening tool for rice salinity tolerance.
The genetics of salinity tolerance in rice was investigated by a nineparent. Pdf improvement of salinity stress tolerance in rice. Stress and disease tolerance irri rice knowledge bank. Here, we provide an updated overview of salt tolerant mechanisms in glycophytes with a particular interest in rice oryza sativa plants. This study was designed to identify useful agronomic parameters for evaluation of salt tolerance and to evaluate genotypes by multiple agronomic parameters for salt tolerance at different growth stages. Vegetable crops water salinity tolerance ecw this table indicates the yield reductions that could be expected when various vegetable crops are irrigated. Effects of salinity stress on growth, chlorophyll content and ion accumulation in two indica rice oriza sativa l. Response regulators 9 and 10 negatively regulate salinity. Genetic dissection of salt tolerance in rice louisiana. Improved salinity tolerance of rice through cell type. Salinity tolerance is an important quality for european rice grown in river deltas. The rice genotypes differed significantly for salt tolerance at seedling. Course material from the usda nrcs training course, management of saline and sodic soils 1991, a series of five training notes by dr. Many qtls for salinity tolerance have been identified 1124.
Screening six varieties of rice oryzasativa for salinity. Effect of salinity on chlorophyll concentration, leaf area. The lack of an effective evaluation method for salt tolerance in the screening process is one of the reasons for limited success in. The development of improved rice varieties with high tolerance of salt stress has been a major and longstanding goal of rice breeding efforts. The literature indicates that rice is sensitive to salinity, particularly during the seedling stage maas and hoffman 1977. Susceptibility or tolerance of rice plants to high salinity is a coordinated action of. Lv1 and lv2 weightings were merged into one variable importance vector. Mechanisms of salinity tolerance in plants have been extensively studied and in the recent years these studies focus on the function of key enzymes and plant morphological traits. Shannon abstract reduction were observed scardaci et al. Effect of salinity stress on growth and carbohydrate. Shannon flood irrigation practices that are commonly used in california et al.
In this study, we quantified the effects of salinity on rgr, tr and tue in. In addition to conventional breeding, other innovative breeding techniques such as tissue culture, induced mutations and wide crosses needed to be explored. Drivers of rice cropping patterns and rice damage by salinity in the coastal delta, cropping patterns and rice damage are strongly driven by level and timing of salinity intrusion, amount and timing of rainfall, water structures, food security policy, and farm income. School of biosciences the university of birmingham august, 20.
Salt tolerance is an important constrain for rice, which is generally categorized as a typical glycophyte. Rice plants were grown in waterlogged conditions, to represent this aspect of irrigated rice fields that should be included in salinity tolerance studies, as the effects of hypoxia on salinity. Modifying sodium transport to improve salinity tolerance of. High salinity causes alfalfa yield to decrease while the leaftostem ratio increases, influencing forage quality. Strategies for rice salinity tolerance in mediterranean france.
Salinity tolerance in irrigated crops 2 nsw department of primary industries, january 2017 note that one megalitre at ecw of 1 dsm contains about 640kg of salts. It also facilitates developing markers for complex traits and combining favorable alleles in breeding lines. Research article open access salinity tolerance, na oryza. Salinity effects on seedling growth and yield components of rice. Salinity tolerance is influenced by many plant, soil, and environmental factors and their. But the concentrations of na, zn, cu and mn increased. An unweighted neighborjoining tree was built using a simple. Tahir nuclear institute for agriculture and biology, faisalabad, pakistan abstract. Salinity tolerance in irrigated crops nsw department of. Identification of candidate genes associated with salt tolerance. Tolerance to mild salinity stress in japonica rice. Review article molecular mechanisms of plant salinity tolerance.
Summary of genetic engineering approach for salinity stress tolerance in rice. The lack of an effective evaluation method for salt tolerance in the screening process is one of the reasons for limited success in conventional salt tolerance breeding. In spite of considerable effort, through both international and national breeding programmes, progress in. Salt stress tolerance is a complex trait, so the qtls related with salt tolerance have significant role in understanding the stress response and generating stresstolerant plants gorantla et al.
Soil salinity is one of the major constraints affecting rice production worldwide, especially in the coastal areas. Engineering salinity tolerance in rice by exogenous expression of cell death regulators v list of publications and conferences thi my linh hoang, brett williams, harjeet khanna, james dale and sagadevan g. Grasses also appear dark green and stunted with leaf burn symptoms. Background salinity is a major abiotic stress limiting yield in many parts of the world. An endophyte from saltadapted pokkali rice confers salttolerance.
Identification of molecular markers tightly linked to salt tolerant genes can serve as land marks for the physical localization of such genes facilitating marker assisted selection mas. Strategies for rice salinity tolerance in mediterranean france puard m. The success of a rice breeding program in developing salt tolerant. Modifying sodium transport to improve salinity tolerance of commercial rice cultivars oryza sativa l. New phenotyping technique for salinity tolerance at. Gregorio and others published screening rice for salinity tolerance, vol 22, irri discussion paper series find, read and cite all the research you need on researchgate. It was thus possible to improve the genetic tolerance of rice varieties to salinity by adopting various breeding methods. Mohammad rashed hossain a thesis submitted to the university of birmingham for the degree of doctor of philosophy. Different salinity affects differently on electrical plant leaf pd of the six varieties of rice. Improvement of salinity stress tolerance in rice mdpi. These studies also suggested that it is possible to combine favorable alleles associated with salt tolerance in a single cultivar through marker.
Salinity effects on seedling growth and yield components of rice linghe zeng and michael c. Information on the relative tolerance of different. In the present study, we screened eight tolerant, eight semitolerant and three sensitive rice genotypes for salinity as well as alkalinity tolerance in saline and. Pdf rice oryza sativa l is an important staple crop that feeds more than one. However, most of the qtls were identified in biparental populations derived from indica accessions such as pokkali and. Sep 16, 2010 this study characterized pokkaliderived quantitative trait loci qtls for seedling stage salinity tolerance in preparation for use in markerassisted breeding. Salinity laboratory, usda ars riverside, ca abstract the capability of crops to grow on saline soils varies among species and depends on the concentration of salts presen t in the rootzone and on various environmental and cultural conditions. As the transcription levels of osrr9 and osrr10 altered under several abiotic stresses, we first characterized their role in salinity tolerance. Assessing trait contribution and mapping novel qtl for salinity. Singh, plant breeder at the international rice research institute, discusses the latest progress in salinty tolerance research in rice. The concentrations of p and k in the tops of rice cultivars decreased with increasing soil salinity. Goals objectives the overall goal of this proposal is to unravel the genetic basis of salt tolerance mechanisms operating in rice and exploit this information to accelerate breeding of rice varieties with improved salt tolerance. New insights on plant salt tolerance mechanisms and.
This method controls soil heterogeneity by using pure sand as a growth medium and minimizes unexpected extreme weather. A new salinity tolerance screening technique using rice seedlings in potculture was tested. Previous studies in rice have suggested the use of several selection criteria to increase salinity tolerance 37,40. Effect of salinity stress on growth and carbohydrate metabolism in three rice oryza sativa l. Regardless, expressing genes in a cell typespecific manner has improved the salinity tolerance of rice and may be useful in improving tolerance to a wide variety of crop stresses including ion toxicities, mineral deficiencies and potentially even biotic stresses of the roots or leaves. Abstract molecular and physiological traits imparting resistancetolerance and susceptibility to a particular biotic and. Review article molecular mechanisms of plant salinity.
Many qtls have been identified in rice for salinity tolerance contributing traits and majority of them have been reported on chromosome 1. Characterizing the saltol quantitative trait locus for salinity tolerance in rice. Natural allelic variation and qtls for salinity tolerance. Evaluation of salt tolerance in rice genotypes by multiple. Salinity tolerance is a complex trait controlled by quantitative trait loci qtls.
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