Evaluation of the effect of qSB-9Tq involved in quantitative resistance to rice sheath blight using near-isogenic lines

2009 ◽  
Vol 89 (4) ◽  
pp. 731-737 ◽  
Author(s):  
Y Yin ◽  
S Zuo ◽  
H Wang ◽  
Z Chen ◽  
S Gu ◽  
...  
Keyword(s):  
Quantitative Trait ◽  
Rating Scale ◽  
Sheath Blight ◽  
Recurrent Parent ◽  
Isogenic Line ◽  
Rice Sheath Blight ◽  
Near Isogenic Lines ◽  
Backcross Population ◽  
Isogenic Lines ◽  
Disease Rating

Resistance to rice sheath blight disease that causes significant yield losses worldwide is controlled by multiple quantitative trait loci (QTL). The accurate resistance effect of qSB-9Tq, a major QTL that derived from the indica cultivar Teqing, was investigated by using a backcross population of Teqing and Lemont (the latter as the recurrent parent) and a set of near-isogenic lines (NIL) developed in this study. A strong pathogenic Rhizoctonia solani line, RH-9, was used for inoculation. Two different experimental designs were adopted. One was a completely randomized experiment in which plants that exhibited three different genotypes at qSB-9Tq locus were distinguished by detecting the marker genotypes flanking qSB-9Tq in the BC6F2 segregation population. The other was a randomized block design experiment with three replicates using the three NILs of qSB-9Tq. The combined results of the two experiments suggested that qSB-9Tq was a dominant resistance QTL and could reduce disease rating by approximately 1.0 using a 0~9 disease rating scale. The results of the study provide a strong foundation for the fine mapping of qSB-9Tq and its utilization in breeding.Key words: Near-isogenic line, quantitative trait locus, resistance effect, rice (Oryza sativa L.), sheath blight

Comparative analysis of genetic background in eight near-isogenic wheat lines with different H genes conferring resistance to Hessian fly

Genome ◽  
2011 ◽  
Vol 54 (1) ◽  
pp. 81-89 ◽  
Author(s):  
S. S. Xu ◽  
C. G. Chu ◽  
M. O. Harris ◽  
C. E. Williams
Keyword(s):  
Genetic Background ◽  
Genetic Similarity ◽  
Triticum Aestivum L ◽  
Hessian Fly ◽  
Pedigree Analysis ◽  
Recurrent Parent ◽  
Linkage Drag ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
H Gene

Near-isogenic lines (NILs) are useful for plant genetic and genomic studies. However, the strength of conclusions from such studies depends on the similarity of the NILs’ genetic backgrounds. In this study, we investigated the genetic similarity for a set of NILs developed in the 1990s to study gene-for-gene interactions between wheat ( Triticum aestivum L.) and the Hessian fly ( Mayetiola destructor (Say)), an important pest of wheat. Each of the eight NILs carries a single H resistance gene and was created by successive backcrossing for two to six generations to susceptible T. aestivum ‘Newton’. We generated 256 target region amplification polymorphism (TRAP) markers and used them to calculate genetic similarity, expressed by the Nei and Li (NL) coefficient. Six of the NILs (H3, H5, H6, H9, H11, and H13) had the highly uniform genetic background of Newton, with NL coefficients from 0.97 to 0.99. However, genotypes with H10 or H12 were less similar to Newton, with NL coefficients of 0.86 and 0.93, respectively. Cluster analysis based on NL coefficients and pedigree analysis showed that the genetic similarity between each of the NILs and Newton was affected by both the number of backcrosses and the genetic similarity between Newton and the H gene donors. We thus generated an equation to predict the number of required backcrosses, given varying similarity of donor and recurrent parent. We also investigated whether the genetic residues of the donor parents that remained in the NILs were related to linkage drag. By using a complete set of ‘Chinese Spring’ nullisomic-tetrasomic lines, one third of the TRAP markers that showed polymorphism between the NILs and Newton were assigned to a specific chromosome. All of the assigned markers were located on chromosomes other than the chromosome carrying the H gene, suggesting that the genetic residues detected in this study were not due to linkage drag. Results will aid in the development and use of near-isogenic lines for studies of the functional genomics of wheat.

scholarly journals Drought Tolerant near Isogenic Lines (NILs) of Pusa 44 Developed through Marker Assisted Introgression of qDTY2.1 and qDTY3.1 Enhances Yield under Reproductive Stage Drought Stress

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Priyanka Dwivedi ◽  
Naleeni Ramawat ◽  
Gaurav Dhawan ◽  
Subbaiyan Gopala Krishnan ◽  
Kunnummal Kurungara Vinod ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Quality ◽  
Reproductive Stage ◽  
Recurrent Parent ◽  
Near Isogenic Lines ◽  
Improvement Project ◽  
Isogenic Lines ◽  
Drought Tolerant ◽  
Rice Improvement

Reproductive stage drought stress (RSDS) is detrimental for rice, which affects its productivity as well as grain quality. In the present study, we introgressed two major quantitative trait loci (QTLs), namely, qDTY2.1 and qDTY3.1, governing RSDS tolerance in a popular high yielding non-aromatic rice cultivar, Pusa 44, through marker-assisted backcross breeding (MABB). Pusa 44 is highly sensitive to RSDS, which restricts its cultivation across drought-prone environments. Foreground selection was carried out using markers, RM520 for qDTY3.1 and RM 521 for qDTY2.1. Background selection was achieved with 97 polymorphic SSR markers in tandem with phenotypic selection to achieve faster recurrent parent genome (RPG) recovery. Three successive backcrosses followed by three selfings aided RPG recoveries of 98.6% to 99.4% among 31 near isogenic lines (NILs). Fourteen NILs were found to be significantly superior in yield and grain quality under RSDS with higher drought tolerance efficiency (DTE) than Pusa 44. Among these, the evaluation of two promising NILs in the multilocational trial during Kharif 2019 showed that they were significantly superior to Pusa 44 under reproductive stage drought stress, while performing on par with Pusa 44 under normal irrigated conditions. These di-QTL pyramided drought-tolerant NILs are in the final stages of testing the All India Coordinated Rice Improvement Project varietal trials for cultivar release. Alternately, the elite drought-tolerant Pusa 44 NILs will serve as an invaluable source of drought tolerance in rice improvement.

scholarly journals Transcriptomic profiling of wheat near-isogenic lines reveals candidate genes on chromosome 3A for pre-harvest sprouting resistance

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xingyi Wang ◽  
Hui Liu ◽  
Kadambot H. M. Siddique ◽  
Guijun Yan
Keyword(s):  
Candidate Genes ◽  
Quantitative Trait ◽  
Genomic Region ◽  
Nucleotide Polymorphisms ◽  
Near Isogenic Lines ◽  
Gene Effects ◽  
Isogenic Lines ◽  
Trait Locus ◽  
Grain Yield And Quality ◽  
Sprouting Resistance

Abstract Background Pre-harvest sprouting (PHS) in wheat can cause severe damage to both grain yield and quality. Resistance to PHS is a quantitative trait controlled by many genes located across all 21 wheat chromosomes. The study targeted a large-effect quantitative trait locus (QTL) QPhs.ccsu-3A.1 for PHS resistance using several sets previously developed near-isogenic lines (NILs). Two pairs of NILs with highly significant phenotypic differences between the isolines were examined by RNA sequencing for their transcriptomic profiles on developing seeds at 15, 25 and 35 days after pollination (DAP) to identify candidate genes underlying the QTL and elucidate gene effects on PHS resistance. At each DAP, differentially expressed genes (DEGs) between the isolines were investigated. Results Gene ontology and KEGG pathway enrichment analyses of key DEGs suggested that six candidate genes underlie QPhs.ccsu-3A.1 responsible for PHS resistance in wheat. Candidate gene expression was further validated by quantitative RT-PCR. Within the targeted QTL interval, 16 genetic variants including five single nucleotide polymorphisms (SNPs) and 11 indels showed consistent polymorphism between resistant and susceptible isolines. Conclusions The targeted QTL is confirmed to harbor core genes related to hormone signaling pathways that can be exploited as a key genomic region for marker-assisted selection. The candidate genes and SNP/indel markers detected in this study are valuable resources for understanding the mechanism of PHS resistance and for marker-assisted breeding of the trait in wheat.

Quantitative Trait Loci Influencing Mycotoxin Contamination of Maize: Analysis by Linkage Mapping, Characterization of Near-Isogenic Lines, and Meta-Analysis

Crop Science ◽  
2014 ◽  
Vol 54 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Santiago X. Mideros ◽  
Marilyn L. Warburton ◽  
Tiffany M. Jamann ◽  
Gary L. Windham ◽  
W. Paul Williams ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Linkage Mapping ◽  
Meta Analysis ◽  
Near Isogenic Lines ◽  
Mycotoxin Contamination ◽  
Isogenic Lines ◽  
Trait Loci

scholarly journals Lipoxygenase activities during development of root and nodule of soybean

2004 ◽  
Vol 39 (7) ◽  
pp. 625-630 ◽  
Author(s):  
Tatiana Góes Junghans ◽  
Maria Goreti de Almeida Oliveira ◽  
Maurilio Alves Moreira
Keyword(s):  
Growth And Development ◽  
Root Formation ◽  
Lipoxygenase Activity ◽  
Post Inoculation ◽  
Isogenic Line ◽  
Near Isogenic Line ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
Bradyrhizobium Elkanii ◽  
Over Time

The objective of this work was to evaluate root and nodule soybean lipoxygenases in Doko cultivar and in a near isogenic line lacking seed lipoxygenases, inoculated and uninoculated with Bradyrhizobium elkanii. The lipoxygenase activities from roots collected at 3, 5, 9, 13, 18 and 28 days post-inoculation and from nodules collected at 13, 18 and 28 days post-inoculation were measured. The pH-activity profiles from root and nodules suggested that the lipoxygenases pool expressed in these organs from Doko cultivar and triple-null near isogenic lines are similar. The root lipoxygenase activity of Doko and triple-null lines, inoculated and uninoculated, reduced over time. The highest lipoxygenase activity observed at the beginning of root formation suggests the involvement of this enzyme in growth and development of this organ. However, for nodules an expressive increase of lipoxygenase activity was noticed 28 days post-inoculation. Root and nodule showed, at least, two mobility groups for lipoxygenases in immunoblottings, with approximately 94 and 97 kDa.

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