The inheritance of systemic resistance to the bacterial blight pathogen (Xanthomonas axonopodis pv. dieffenbachiae) in Anthurium andraeanum (Hort.)

2007 ◽  
Vol 115 (1) ◽  
pp. 76-81 ◽  
Author(s):  
W. Elibox ◽  
P. Umaharan
2008 ◽  
Vol 98 (4) ◽  
pp. 421-426 ◽  
Author(s):  
W. Elibox ◽  
P. Umaharan

The genetic basis of systemic resistance to bacterial blight disease (blight) of anthurium (Anthurium andraeanum) caused by Xanthomonas axonopodis pv. dieffenbachiae was investigated in progenies of 53 crosses involving 31 parent cultivars using segregation analysis. Inoculation of parents and progenies was achieved by injecting the petiole base of the most recent fully expanded leaf with 100 μl of 109 colony forming units per ml of the blight pathogen (strain X4gfp) transformed with the green fluorescent protein (GFP) gene. The time to death and the presence or absence of GFP fluorescence on newly emerging leaves was monitored over a period of 30 weeks after inoculation (WAI), on an individual plant basis. The expected resistance to susceptible ratios based on a digenic model involving two dominant genes, designated A and B, interacting according to a duplicate recessive epistasis model fitted the observed segregation ratios in the crosses. Based on the segregation ratios obtained, the parental cultivars were assigned plausible genotypes. There were significant differences (P < 0.001) in time to death following inoculation between the various genotypic designations. Cultivars with genotypes AABB, AABb, AaBB, and AaBb died within 10 WAI and designated as susceptible; AAbb and aaBB died from 18.8 to 25.6 WAI and were designated as moderately resistant; and Aabb, aaBb, and aabb produced resistant phenotypes. There was also some evidence for dosage effect especially in the highly resistant category. Hence, (AABb = AaBB = AaBb) < (aaBB = AAbb) < Aabb = aaBb = aabb). An approach to fixing resistance to blight in anthurium is discussed.


Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 448-455 ◽  
Author(s):  
Defu Wang ◽  
Yajun Wang ◽  
Maoqiang Fu ◽  
Shuyuan Mu ◽  
Bing Han ◽  
...  

Powdery mildew, one of devastating diseases of wheat worldwide, is caused by Erysiphe graminis f. sp. tritici, a fungal species with constant population changes, which often poses challenges in disease management with host resistance. Transgenic approaches that utilize broad-spectrum resistance may limit changes of pathogen populations and contribute to effective control of the disease. The harpin protein Hpa1, produced by the rice bacterial blight pathogen, can induce resistance to bacterial blight and blast in rice. The fragment comprising residues 10 through 42 of Hpa1, Hpa110-42, is reportedly three- to eightfold more effective than the full-length protein. This study evaluated the transgenic expression of the Hpa110-42 gene for resistance to powdery mildew in wheat caused by E. graminis f. sp. tritici. Nine Hpa110-42 transgenic wheat lines were generated. The genomic integration of Hpa110-42 was confirmed, and expression of the transgene was detected at different levels in the individual transgenic lines. Following inoculation with the E. graminis f. sp. tritici isolate Egt15 in the greenhouse, five transgenic lines had significantly higher levels of resistance to powdery mildew compared with nontransformed plants. Thus, transgenic expression of Hpa110-42 conferred resistance to one isolate of E. graminis f. sp. tritici in wheat in the greenhouse.


2010 ◽  
Vol 158 (4) ◽  
pp. 288-295 ◽  
Author(s):  
Sascha D. Braun ◽  
Janine Hofmann ◽  
Annette Wensing ◽  
Helge Weingart ◽  
Matthias S. Ullrich ◽  
...  

2013 ◽  
Vol 14 (1) ◽  
pp. 41 ◽  
Author(s):  
Y. He ◽  
G. P. Munkvold

Xanthomonas axonopodis pv. phaseoli (Smith) Vauterin (Xap) and Xanthomonas fuscans subsp. fuscans Schaad et al. (Xff) cause indistinguishable symptoms known as common bacterial blight of bean (Phaseolus vulgaris L.). These results confirm a higher disease incidence and seed transmission frequency of Xff compared to Xap and reinforce the need for seed health tests that can differentiate the two species. Accepted for publication 21 August 2013. Published 23 September 2013.


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