Identification and confirmation of greenbug resistance loci in an advanced mapping population of sorghum

2017 ◽  
Vol 155 (10) ◽  
pp. 1610-1622 ◽  
Author(s):  
SOMASHEKHAR PUNNURI ◽  
YINGHUA HUANG

SUMMARYGreenbug infestations to sorghum can cause severe and above economic threshold damage in the Great Plains of the United States. The current study was conducted to identify quantitative trait loci (QTLs) and potential candidate genes residing within the QTL region responsible for greenbug resistance in an advanced mapping population. Inter-crossed populations are useful in detecting QTLs tightly linked to genetic markers with high resolution. In the current study, QTLs responsible for greenbug resistance in sorghum were mapped using an inter-cross population derived from two parents, BTx623 (greenbug-susceptible line) and PI 607900 (greenbug-resistant line). Molecular markers for 115 loci were used to construct a linkage map which eventually facilitated tagging portions of the sorghum genome regions responsible for greenbug resistance. The molecular genetic map covered all the chromosomes of sorghum with a total genome length of 963·0 cM. The advanced mapping population revealed and confirmed the location of greenbug resistance loci, which explained a high phenotypic variation from 72·9 to 80·9% of greenbug resistance. The loci for greenbug resistance were mapped to the region flanked by markers Starssbnm 93 and Starssbnm 102 on chromosome 9 with an increased allelic effect from the resistant parent. The locations of these loci were compared with a previous study on QTL analysis using an F2 mapping population. The results from the present study were in agreement with the findings in the F2 QTL analysis and identified QTLs had a better confidence interval. The markers/QTLs identified from the current study can be effectively utilized in marker-assisted selection and map-based cloning experiments.

2011 ◽  
Vol 25 (2) ◽  
pp. 2315-2320 ◽  
Author(s):  
Y.H. Zhao ◽  
Y.S. Guo ◽  
J.X. Fu ◽  
S.S. Huang ◽  
B.B. Lu ◽  
...  

2009 ◽  
Vol 35 (12) ◽  
pp. 2159-2166 ◽  
Author(s):  
Xin-Le YANG ◽  
Zhi-Wei WANG ◽  
Gui-Yin ZHANG ◽  
Yu-Xin PAN ◽  
Li-Qiang WU ◽  
...  

2020 ◽  
Vol 110 (9) ◽  
pp. 1511-1521
Author(s):  
Juliet Wilkes ◽  
Christopher Saski ◽  
Mariola Klepadlo ◽  
Benjamin Fallen ◽  
Paula Agudelo

Reniform nematode (Rotylenchulus reniformis) is a yield-limiting pathogen of soybean (Glycine max) in the southeastern region of the United States. A population of 250 recombinant inbred lines (RIL) (F2:8) developed from a cross between reniform nematode resistant soybean cultivar Forrest and susceptible cultivar Williams 82 was utilized to identify regions associated with host suitability. A genetic linkage map was constructed using single-nucleotide polymorphism markers generated by genotyping-by-sequencing. The phenotype was measured in the RIL population and resistance was characterized using normalized and transformed nematode reproduction indices in an optimal univariate cluster analysis. Quantitative trait loci (QTL) analysis using normalized phenotype scores identified two QTLs on each arm of chromosome 18 (rrn-1 and rrn-2). The same QTL analysis performed with log10(x) transformed phenotype data also identified two QTLs: one on chromosome 18 overlapping the same region in the other analysis (rrn-1), and one on chromosome 11 (rrn-3). While rrn-1 and rrn-3 have been reported associated with reduced reproduction of reniform nematode, this is the first report of the rrn-2 region associated with host suitability to reniform nematode. The resistant parent allele at rrn-2 showed an inverse relationship with the resistance phenotype, correlating with an increase in nematode reproduction or host suitability. Several candidate genes within these regions corresponded with host plant defense systems. Interestingly, a characteristic pathogen resistance gene with a leucine-rich repeat was discovered within rrn-2. These genetic markers can be used by soybean breeders in marker-assisted selection to develop lines with resistance to reniform nematode.


Genetics ◽  
1986 ◽  
Vol 112 (2) ◽  
pp. 321-342
Author(s):  
Eugene M Rinchik ◽  
Liane B Russell ◽  
Neal G Copeland ◽  
Nancy A Jenkins

ABSTRACT Genes of the dilute-short ear (d-se) region of mouse chromosome 9 comprise an array of loci important to the normal development of the animal. Over 200 spontaneous, chemically induced and radiation-induced mutations at these loci have been identified, making it one of the most genetically well-characterized regions of the mouse. Molecular analysis of this region has recently become feasible by the identification of a dilute mutation that was induced by integration of an ecotropic murine leukemia virus genome. Several unique sequence cellular DNA probes flanking this provirus have now been identified and used to investigate the organization of wild-type chromosomes and chromosomes with radiation-induced d-se region mutations. As expected, several of these mutations are associated with deletions, and, in general, the molecular and genetic complementation maps of these mutants are concordant. Furthermore, a deletion break-point fusion fragment has been identified and has been used to orient the physical map of the d-se region with respect to the genetic complementation map. These experiments provide important initial steps for analyzing this developmentally important region at the molecular level, as well as for studying in detail how a diverse group of mutagens acts on the mammalian germline.


Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 984-989 ◽  
Author(s):  
Sandra E. Branham ◽  
Amnon Levi ◽  
W. Patrick Wechter

Fusarium wilt race 1, caused by the soilborne fungus Fusarium oxysporum Schlechtend.: Fr. f. sp. niveum (E.F. Sm.) W.C. Snyder & H.N. Hans (Fon), is a major disease of watermelon (Citrullus lanatus) in the United States and throughout the world. Although Fusarium wilt race 1 resistance has been incorporated into several watermelon cultivars, identification of additional genetic sources of resistance is crucial if a durable and sustainable level of resistance is to be continued over the years. We conducted a genetic mapping study to identify quantitative trait loci (QTLs) associated with resistance to Fon race 1 in segregating populations (F2:3 and recombinant inbred lines) of Citrullus amarus (citron melon) derived from the Fon race 1 resistant and susceptible parents USVL246-FR2 and USVL114, respectively. A major QTL (qFon1-9) associated with resistance to Fon race 1 was identified on chromosome 9 of USVL246-FR2. This discovery provides a novel genetic source of resistance to Fusarium wilt race 1 in watermelon and, thus, an additional host-resistance option for watermelon breeders to further the effort to mitigate this serious phytopathogen.


Author(s):  
Anthony DeAngelis ◽  
Francina Dominguez ◽  
Ying Fan ◽  
Alan Robock ◽  
M. Deniz Kustu ◽  
...  

1977 ◽  
Vol 57 (3) ◽  
pp. 729-733 ◽  
Author(s):  
L. C. DARLINGTON ◽  
D. E. MATHRE ◽  
R. H. JOHNSTON

Isolates of Claviceps purpurea (Fr.) Tul. originally isolated from many different grass hosts in the northern Great Plains and several other areas in the United States and England were tested for their pathogenicity to selected cultivars or lines of male-sterile wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). While there was a great range in the level of virulence, no clear-cut evidence of specific races was obtained. A few isolates were weakly virulent on two cultivars of male-sterile spring wheat but were highly virulent on the other two cultivars tested. Wheat and barley breeders are advised to use a mixture of isolates in screening germ plasm for resistance to ergot.


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