scholarly journals Quantitative Trait Loci for Component Physiological Traits Determining Salt Tolerance in Rice

2001 ◽  
Vol 125 (1) ◽  
pp. 406-422 ◽  
Author(s):  
Mikiko L. Koyama ◽  
Aurora Levesley ◽  
Robert M.D. Koebner ◽  
Timothy J. Flowers ◽  
Anthony R. Yeo
Keyword(s):  
Quantitative Trait Loci ◽  
Salt Tolerance ◽  
Quantitative Trait ◽  
Physiological Traits ◽  
Trait Loci

scholarly journals Meta-Analysis of Quantitative Trait Loci Associated with Seedling-Stage Salt Tolerance in Rice (Oryza sativa L.)

Plants ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 33 ◽  
Author(s):  
Md. Islam ◽  
John Ontoy ◽  
Prasanta Subudhi
Keyword(s):  
Quantitative Trait Loci ◽  
Salt Tolerance ◽  
Candidate Genes ◽  
Quantitative Trait ◽  
Oryza Sativa L ◽  
Meta Analysis ◽  
Seedling Stage ◽  
Phenotypic Variance ◽  
A Genome ◽  
Trait Loci

Soil and water salinity is one of the major abiotic stresses that reduce growth and productivity in major food crops including rice. The lack of congruence of salt tolerance quantitative trait loci (QTLs) in multiple genetic backgrounds and multiple environments is a major hindrance for undertaking marker-assisted selection (MAS). A genome-wide meta-analysis of QTLs controlling seedling-stage salt tolerance was conducted in rice using QTL information from 12 studies. Using a consensus map, 11 meta-QTLs for three traits with smaller confidence intervals were localized on chromosomes 1 and 2. The phenotypic variance of 3 meta-QTLs was ≥20%. Based on phenotyping of 56 diverse genotypes and breeding lines, six salt-tolerant genotypes (Bharathy, I Kung Ban 4-2 Mutant, Langmanbi, Fatehpur 3, CT-329, and IARI 5823) were identified. The perusal of the meta-QTL regions revealed several candidate genes associated with salt-tolerance attributes. The lack of association between meta-QTL linked markers and the level of salt tolerance could be due to the low resolution of meta-QTL regions and the genetic complexity of salt tolerance. The meta-QTLs identified in this study will be useful not only for MAS and pyramiding, but will also accelerate the fine mapping and cloning of candidate genes associated with salt-tolerance mechanisms in rice.

scholarly journals Chlorophyll Retention and High Photosynthetic Performance Contribute to Salinity Tolerance in Rice Carrying Drought Tolerance Quantitative Trait Loci (QTLs)

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 620
Author(s):  
Noppawan Nounjan ◽  
Wuttipong Mahakham ◽  
Jonaliza L. Siangliw ◽  
Theerayut Toojinda ◽  
Piyada Theerakulpisut
Keyword(s):  
Salt Stress ◽  
Quantitative Trait Loci ◽  
Salt Tolerance ◽  
Drought Tolerance ◽  
Quantitative Trait ◽  
Photosynthetic Performance ◽  
Chromosome 8 ◽  
Recurrent Parent ◽  
Putative Gene ◽  
Trait Loci

Jasmine rice (Oryza sativa L.), or Khao Dawk Mali 105 (KDML105), is sensitive to drought and salt stresses. In this study, two improved drought-tolerant chromosome segment substitution lines (CSSLs) of KDML105 (CSSL8-103 and CSSL8-106), which carry drought tolerance quantitative trait loci (QTLs) on chromosome 8, were evaluated for salt tolerance and were compared with KDML105 and the QTL donor DH103, their parents and the salt-tolerant genotype Pokkali. After being subjected to salt stress for 6 days, 3-week-old seedlings of Pokkali showed the highest salt tolerance. Parameters related to photosynthesis were less inhibited in both CSSLs and the donor DH103, while these parameters were more severely damaged in the recurrent parent KDML105. Albeit a high ratio of Na+/K+, CSSLs and DH103 showed similar or higher contents of soluble sugar and activity of superoxide dismutase (SOD; EC1.15.1.1) compared with Pokkali, indicating possible mechanisms of either tissue or osmotic tolerance in these plants. The expression of a putative gene Os08g41990 (aminotransferase), which is located in DT-QTL and is involved in chlorophyll biosynthesis, significantly decreased under salt stress in KDML105 and CSSL8-103, while no obvious change in the expression of this gene was observed in Pokkali, DH103 and CSSL8-106. This gene might play a role in maintaining chlorophyll content under stress conditions. Taken together, the results of this study indicate that DT-QTL could contribute to the enhancement of photosynthetic performance in CSSL lines, leading to changes in their physiological ability to tolerate salinity stress.

QTL analysis of Na+ and Cl- accumulation related traits in an intergeneric BC1 progeny of Citrus and Poncirus under saline and nonsaline environments

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 692-705 ◽  
Author(s):  
Ilhami Tozlu ◽  
Charles L Guy ◽  
Gloria A Moore
Keyword(s):  
Quantitative Trait Loci ◽  
Salt Tolerance ◽  
Quantitative Trait ◽  
Transgressive Segregation ◽  
Poncirus Trifoliata ◽  
Chloride Salt ◽  
Correlation Analyses ◽  
Whole Plant ◽  
Trait Loci ◽  
Citrus Genome

The effects of salinization with 40 mM NaCl on Poncirus trifoliata (L.) Raf., Citrus grandis (L.) Osb., their F1, and a BC1 progeny population (C. grandis × (F1)) were investigated by means of Na+ and Cl- analyses and QTL (quantitative trait loci) mapping. A total of 38 traits related to different tissue or whole-plant Na+ and (or) Cl- accumulation was analyzed in salinized and nonsalinized BC1 progeny clones. The comparison of the three parental types with the BC1 progeny under control and saline conditions showed that the BC1 progeny plants segregated transgressively for many traits. First mapping analyses resulted in a total of 73 potential quantitative trait loci (PQTL) with LOD scores [Formula: see text]3.0 located on a previously generated linkage map. Fifty-three percent of the mapped PQTLs were for traits associated with salinity. The small progeny population size used made further analyses of these PQTLs necessary. By considering LOD scores, map locations, and correlation analyses of the traits, it was possible to identify 17 regions of the citrus genome of interest: 8 of them may contain genuine QTLs of large effect and 9 regions are worthy of further study. Correlation analyses and locations of PQTLs indicated that many traits were controlled by fewer genes than the actual number of QTLs mapped for them. For example, 21 PQTLs mapped for Na+ accumulation and Cl-/Na+ ratios were located in a cluster at the beginning of one linkage group (LG), while 10 PQTLs mapped for Cl- accumulation and Cl-/Na+ ratios were located in a cluster at the beginning of another LG. This is the first step in identifying QTLs that have a major impact on salt tolerance and (or) mineral accumulation in citrus.Key words: Citrus grandis, Poncirus trifoliata, salinity stress, QTL mapping, transgressive segregation, mineral analysis, sodium, chloride, salt tolerance, citrus genetics.

Comparison of salt tolerance during seed germination and vegetative growth in tomato by QTL mapping

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 727-734 ◽  
Author(s):  
M R Foolad
Keyword(s):  
Quantitative Trait Loci ◽  
Salt Tolerance ◽  
Seed Germination ◽  
Lycopersicon Esculentum ◽  
Quantitative Trait ◽  
Vegetative Growth ◽  
Developmental Stages ◽  
Phenotypic Correlation ◽  
Recurrent Parent ◽  
Trait Loci

The purpose of this study was to determine the genetic relationship between salt tolerance during seed germination and vegetative growth in tomato by comparing quantitative trait loci (QTLs) which confer salt tolerance at these two developmental stages. A salt-sensitive Lycopersicon esculentum line (NC84173; maternal and recurrent parent) was hybridized with a salt-tolerant accession (LA722) of Lycopersicon pimpinellifolium, and BC1 and BC1S1 populations were developed. The BC1 population was used for RFLP mapping and the BC1S1 population for evaluation of salt tolerance during germination and vegetative growth. The results indicated the presence of a small but significant correlation (r = -0.22, p < 0.05) between rate of seed germination and the percentage of plant survival under salt stress. Seven and five QTLs were identified for salt tolerance during seed germination and vegetative growth, respectively. While in most cases the location of QTLs for germination was different from that for vegetative growth, there were some coincidences in QTL locations; this was consistent with the small phenotypic correlation observed between the two traits. The overall results indicated that, in these tomato genetic materials, salt tolerance during seed germination was independent of that during vegetative growth. However, simultaneous improvement of tolerance at the two developmental stages should be possible through marker-assisted selection and breeding.Key words: Lycopersicon esculentum, L. pimpinellifolium, salt tolerance, seed germination vegetative growth, restriction fragment length polymorphism (RFLP), quantitative trait loci (QTLs).

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