scholarly journals Four Near-Isogenic Lines of Cotton with Different Genes for Bacterial Blight Resistance

2002 ◽  
Vol 92 (12) ◽  
pp. 1323-1328 ◽  
Author(s):  
Margaret Essenberg ◽  
Melanie B. Bayles ◽  
Roushan A. Samad ◽  
Judy A. Hall ◽  
L. A. Brinkerhoff ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Xanthomonas Campestris ◽  
Avirulence Gene ◽  
Recurrent Parent ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
Race 1 ◽  
Selection For ◽  
Dominant Genes

The development and genetic characterization of four near-isogenic lines (NILs) of cotton (Gossypium hirsutum) is described herein. Each line contains a single, but different, gene for resistance to bacterial blight caused by Xanthomonas campestris pv. malvacearum. The lines were derived using at least six backcrosses to the susceptible recurrent parent ‘Acala 44’, followed by single plant-progeny row selection for uniformity. The NILs are homozygous for the B2, B4, BIn, or b7 genes and are designated as AcB2, AcB4, AcBIn, and Acb7, respectively. In the ‘Acala 44’ background, B2, B4, and BIn are partially dominant genes; b7 is partially recessive. Relative strengths of resistance conferred by those genes toward race 1 of the pathogen were B4˜b7>BIn˜B2. B4, BIn, and b7 each conferred resistance toward X. campestris pv. malvacearum carrying a single avirulence gene, whereas B2 was less specific.

Construction and evaluation of near-isogenic lines for major QTLs of basal root thickness and 1000-grain-weight in lowland and upland rice

2007 ◽  
Vol 4 (3) ◽  
pp. 199-205 ◽  
Author(s):  
Liu Li-Feng ◽  
Zhang Hong-Liang ◽  
Mu Ping ◽  
Qu Yan-Ying ◽  
Li Zi-Chao
Keyword(s):  
Molecular Marker ◽  
Upland Rice ◽  
Grain Weight ◽  
Recurrent Parent ◽  
Near Isogenic Lines ◽  
Major Qtls ◽  
Isogenic Lines ◽  
Root Thickness ◽  
Selection For ◽  
1000 Grain Weight

AbstractThe development of near-isogenic lines (NILs) is an important fundamental step in the cloning of quantitative trait loci (QTL) and molecular marker assisted breeding. In the present study, NILs for two major QTLs of basal root thickness (BRT) and 1000-grain-weight (TGW) were obtained by molecular marker-assisted selection (MAS) through foreground selection for target QTL and background selection in three backcross generations (BC1F1, BC2F1 and BC3F1). After phenotypic evaluation in the BC3F2 generation, nine BRT QTL-NILs with BRT ranges of 1.07–1.16 mm (6.11–15.18% greater than the recurrent parent) and an average recovery ratio of genetic background (RRGB) of 97.22%, and 11 TGW QTL-NILs with ranges of 21.25–26.25 g (7.05–32.16% greater than the recurrent parent) and 95.97% of RRGB, were selected.

scholarly journals Resistance to Scald (Rhynchosporium secalis) in Barley (Hordeum vulgare) Studied by Near-Isogenic Lines: I. Markers and Differential Isolates

2002 ◽  
Vol 92 (7) ◽  
pp. 710-720 ◽  
Author(s):  
Å. Bjørnstad ◽  
V. Patil ◽  
A. Tekauz ◽  
A. G. Marøy ◽  
H. Skinnes ◽  
...  
Keyword(s):  
Hordeum Vulgare ◽  
Molecular Marker ◽  
Genetic Characterization ◽  
Rhynchosporium Secalis ◽  
Recurrent Parent ◽  
Near Isogenic Lines ◽  
Marker System ◽  
Isogenic Lines ◽  
Pairwise Differences

Near-isogenic lines (NILs) with resistance for scald in seventh generation backcross with ‘Ingrid’ as recurrent parent (RP) were tested with seven differential isolates of Rhynchosporium secalis in Norway and Canada. NILs of ‘Turk’, ‘Brier’, ‘CI 8162’, ‘La Mesita’, ‘Hispont’, ‘Atlas 46’, ‘Modoc’, ‘Hudson’, ‘Abyssinian’, ‘Steudelli’, and ‘CI 2222’ also were evaluated for field reactions. The genetic characterization of the NILs (degree of isogeneity with Ingrid) and with each other was carried out. The molecular marker pattern shows that the backcrossing program has resulted in from 86.3 to 100% RP genome in the NILs, depending on the marker system. On an average, 96% RP genome was found in the NILs. There were certain consistent (pairwise) differences between the NILs and RP on chromosomes 3H and 7H. Both chromosomes are known to contain loci conferring resistance to R. secalis, indicating successful introgression from the donors into the NILs. Approximately two-thirds of the observed RP-NIL polymorphisms were linked to the assumed resistance in the NIL. Based on the marker and phenotypic analyses of the NILs, suggestions for a more appropriate and updated terminology of genes for resistance to R. secalis in barley are made. The proposed changes in nomenclature also indicate the differentials that are available as NILs and those lacking.

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.

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 Pyramiding B Genes in Cotton Achieves Broader But Not Always Higher Resistance to Bacterial Blight

2014 ◽  
Vol 104 (10) ◽  
pp. 1088-1097 ◽  
Author(s):  
Margaret Essenberg ◽  
Melanie B. Bayles ◽  
Margaret L. Pierce ◽  
Laval M. Verhalen
Keyword(s):  
Upland Cotton ◽  
Bacterial Blight ◽  
Specific Resistance ◽  
Near Isogenic Lines ◽  
Bacterial Populations ◽  
North Central ◽  
Race 1 ◽  
The One ◽  
Isogenic Strains ◽  
Avr Genes

Near-isogenic lines of upland cotton (Gossypium hirsutum) carrying single, race-specific genes B4, BIn, and b7 for resistance to bacterial blight were used to develop a pyramid of lines with all possible combinations of two and three genes to learn whether the pyramid could achieve broad and high resistance approaching that of L. A. Brinkerhoff's exceptional line Im216. Isogenic strains of Xanthomonas axonopodis pv. malvacearum carrying single avirulence (avr) genes were used to identify plants carrying specific resistance (B) genes. Under field conditions in north-central Oklahoma, pyramid lines exhibited broader resistance to individual races and, consequently, higher resistance to a race mixture. It was predicted that lines carrying two or three B genes would also exhibit higher resistance to race 1, which possesses many avr genes. Although some enhancements were observed, they did not approach the level of resistance of Im216. In a growth chamber, bacterial populations attained by race 1 in and on leaves of the pyramid lines decreased significantly with increasing number of B genes in only one of four experiments. The older lines, Im216 and AcHR, exhibited considerably lower bacterial populations than any of the one-, two-, or three-B-gene lines. A spreading collapse of spray-inoculated AcBIn and AcBInb7 leaves appears to be a defense response (conditioned by BIn) that is out of control.

scholarly journals Maize nested introgression library provides evidence for the involvement of liguleless1 in resistance to northern leaf blight

2019 ◽  
Author(s):  
Judith M. Kolkman ◽  
Josh Strable ◽  
Kate Harline ◽  
Dallas E. Kroon ◽  
Tyr Wiesner-Hanks ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Association Analysis ◽  
Crop Improvement ◽  
Leaf Blight ◽  
Leaf Angle ◽  
Recurrent Parent ◽  
Near Isogenic Lines ◽  
Northern Leaf Blight ◽  
Leaf Architecture ◽  
Isogenic Lines

AbstractPlant disease resistance is largely governed by complex genetic architecture. In maize, few disease resistance loci have been characterized. Near-isogenic lines (NILs) are a powerful genetic tool to dissect quantitative trait loci (QTL). We analyzed an introgression library of maize near-isogenic lines (NILs), termed a nested NIL (nNIL) library for resistance to northern leaf blight (NLB) caused by the fungal pathogen Setosphaeria turcica. The nNIL library was comprised of 412 BC5F4 NILs that originated from 18 diverse donor parents and a common recurrent parent, B73. Single nucleotide polymorphisms identified through genotyping by sequencing (GBS) were used to define introgressions and for association analysis. NILs that conferred resistance and susceptibility to NLB were comprised of introgressions that overlapped known NLB QTL. Genome-wide association analysis and stepwise regression further resolved five QTL regions, and implicated several candidate genes, including Liguleless1 (Lg1), a key determinant of leaf architecture in cereals. Two independently-derived mutant alleles of lg1 inoculated with S. turcica showed enhanced susceptibility to NLB. In the maize nested association mapping population, leaf angle was positively correlated with NLB in five recombinant inbred line (RIL) populations, and negatively correlated with NLB in four RIL populations. This study demonstrates the power of a nNIL library combined with high density SNP coverage to resolve QTLs. Furthermore, the role of lg1 in leaf architecture and in resistance to NLB has important applications in crop improvement.Significance Statement (120 words)Understanding the genetic basis of disease resistance is important for crop improvement. We analyzed response to northern leaf blight (NLB) in a maize population consisting of 412 near-isogenic lines (NILs) derived from 18 diverse donor parents backcrossed to a recurrent parent, B73. NILs were genotyped by sequencing to detect introgressed segments. We identified NILs with greater resistance or susceptibility to NLB than B73. Genome-wide association analysis, coupled with stepwise regression, identified 5 candidate loci for NLB resistance, including the liguleless1 gene. The LIGULELESS1 transcription factor is critical in development of the leaf ligular region and influences leaf angle. We found that liguleless1 mutants are significantly more susceptible to NLB, uncovering a pleiotropic role for liguleless1 in development and disease resistance.

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