scholarly journals Resistance Sources to Xanthomonas fragariae in Non-octoploid Strawberry Species

HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1653-1656 ◽  
Author(s):  
Shiming Xue ◽  
Robert H. Bors ◽  
Stephen E. Strelkov
Keyword(s):  
Disease Severity ◽  
Hypersensitive Reaction ◽  
Symptom Development ◽  
Sources Of Resistance ◽  
Bacterial Populations ◽  
Resistance Sources ◽  
Inoculation Site ◽  
Xanthomonas Fragariae ◽  
Moderately Resistant ◽  
Resistant Genotypes

Forty-three accessions from 11 strawberry species were screened in the greenhouse for resistance to three strains of Xanthomonas fragariae Kennedy and King. Among the accessions tested, Pen-5 of Fragaria pentaphylla Losink expressed either no symptoms or a hypersensitive reaction, while accessions Pen-2 and Pen-4 developed either no symptoms or restricted water-soaked lesions. Two accessions of F. moschata Duch were characterized by reduced translucency at the inoculation site in the course of symptom development. These accessions, representing three resistance types, were classified as highly resistant, resistant, and moderately resistant, respectively, based on mean separation of disease severity ratings. The classifications proved to be consistent with the results from measurements of bacterial populations on inoculated leaves of those genotypes. The study suggests that species of F. pentaphylla and F. moschata harbour diversified sources of resistance. Resistant genotypes were not detected in F. nilgerrensis Schlect, F. daltoniana J. Gay, F. nubicola Lindl, F. gracilis Losinsk, F. iinumae Makino, F. vesca L., F. viridis Duch, or F. orientalis Losinsk.

Resistance in Mungbean Against Meloidogyne incognita and its Impact on Nodulation

2020 ◽  
Author(s):  
Narpinderjeet Kaur Dhillon ◽  
Rohit Kumar ◽  
Sukhjeet Kaur ◽  
Anupam Anupam ◽  
Asmita Srari
Keyword(s):  
Plant Growth ◽  
Growth Parameters ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Kharif Season ◽  
Breeding Programmes ◽  
Meloidogyne Spp ◽  
Moderately Resistant ◽  
The Impact ◽  
Resistant Genotypes

Mungbean is an economically as well as nutritionally enriched crop. Of the different soil borne pathogens attacking mungbean, root-knot nematode (Meloidogyne spp.) is an important pathogen affecting growth and production of mungbean. It is grown in summer as well as in kharif season. The germplasm of mungbean of two seasons’ viz., summer and kharif was screened to identify new sources of resistance against root knot nematode, M. incognita. In addition to screening; studies were also conducted on the impact of root knot nematode infestation in roots on nodulation character of mungbean and growth parameters. Of the sixty three genotypes evaluated in summer, seven were found to be moderately resistant. In kharif season, only three genotypes were found to be moderately resistant. M. incognita infestation was also observed to affect the plant growth parameters as well as nodulation on roots of mungbean genotypes. Comparatively, better plant growth and higher nodulation was observed in moderately resistant genotypes as compared to the susceptible ones. The ten identified moderately resistant genotypes from two seasons can be a useful source in breeding programmes for developing cultivars to manage root knot nematode.

scholarly journals Evaluation of maize genotypes for Turcicum leaf blight (Exserohilum turcicum) in Terai and inner terai of Nepal

2016 ◽  
Vol 2 (1) ◽  
pp. 109-116
Author(s):  
Tirtha Raj Rijal ◽  
Govind KC ◽  
Kesab Babu Koirala ◽  
Jiban Shrestha
Keyword(s):  
Disease Severity ◽  
Pooled Analysis ◽  
Leaf Blight ◽  
Exserohilum Turcicum ◽  
Sources Of Resistance ◽  
Maize Productivity ◽  
Maize Genotypes ◽  
Disease Severity Scale ◽  
High Yielding Varieties ◽  
Moderately Resistant

Thirty maize genotypes in 2014-2015 at Dumarwana, Nijgadh, Keureni and Rampur and ten genotypes in 2015-2016 at Anandpur, Shitalnagar, Dumarwana, Nijgadh and Rampur were evaluated for resistance to Turcicum leaf blight (Exserohilum turcicum) under farmers field conditions. The scale used for disease severity ranged from 1-5 scale based on the proportionate leaf area affected by the disease. The combined analysis over locations in 2014-2015 showed that among the 30 genotypes 25 genotypes were resistant (1.0-2.0 scale), and 5 genotypes were moderately resistant (2.1-3.0 scale). Similarly the pooled analysis over locations in 2015-2016 showed that 7 genotypes were resistant (1.0-2.0 scale) and 3 genotypes were moderately resistant (2.1-3.0 scale). The maize genotypes namely Z376-26, Z478-3, Z433-99, Z464-5, Z478-2, Z466-1, CAH1513, RML-95/RML-96, CAH1515, CAH1521, CAH1515, CAH151, CAH153, ZH114228 , Z376-9, Z466-3, Z376-5, RML-32/RML-17, RML-86/RML-96 and 900MGold were resistant with disease severity scale of 1.5 and with higher grain yield in both the years. Thus above genotypes were identified as promising sources of resistance against E. turcicum and they can be used to develop disease resistant and high yielding varieties to enhance maize productivity in terai and inner terai of Nepal.

scholarly journals Reaction of melon genotypes to Rhizoctonia solani

2008 ◽  
Vol 26 (3) ◽  
pp. 401-403 ◽  
Author(s):  
Sami J Michereff ◽  
Domingos EGT Andrade ◽  
Rui Sales Júnior
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Severity ◽  
Cucumis Melo ◽  
Infested Soil ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Root Diseases ◽  
Brazilian Northeast ◽  
Cucumis Melo L ◽  
Resistant Genotypes

The intensive exploration of melon (Cucumis melo L.) crops in the Brazilian Northeast favors the occurrence of root diseases such as the Rhizoctonia canker, caused by Rhizoctonia solani. Twenty melon genotypes were challenged against the pathogen isolates RS-9 and RS-10 aiming at selecting those potentially useful for breeding programs and/or integrated disease management. Seeds were planted in infested soil (50 mg of colonized rice grains kg-1 of soil). Disease severity was assessed 15 days after inoculation, by means of a disease scale from 0 to 4, used later to cluster genotypes in five classes. None of the genotypes presented immune-like reaction to R. solani, independent of the pathogen isolate. Disease severity ranged from 6.2 to 85.4% and from 7.8 to 85.2%, for isolates RS-9 and RS-10, respectively. When both isolates were considered simultaneously, genotypes Sancho, AF-1805, Athenas, AF-682, Torreon, and Galileo were highly resistant. Genotypes Sancho and AF-1805 had the lowest disease severity levels in relation to isolate RS-9, and genotype Gold Pride, in relation to RS-10. These genotypes differed significantly from the others, within isolates. Therefore, they are potential sources of resistance to R. solani and should be considered as a priority planting choice in infested areas.

scholarly journals Induction of post-infection ethylene and its role in resistance of bean (Phaseolus vulgaris) against Colletotrichum lindemuthianum

2011 ◽  
Vol 39 (No. 3) ◽  
pp. 79-87 ◽  
Author(s):  
J. Ombiri ◽  
V. Zinkernagel ◽  
E.M. Gathuru ◽  
O. Achwanya ◽  
A. Lebeda
Keyword(s):  
Phaseolus Vulgaris ◽  
Ethylene Production ◽  
Post Infection ◽  
Colletotrichum Lindemuthianum ◽  
Rapid Decline ◽  
Symptom Development ◽  
Sharp Rise ◽  
Inoculation Techniques ◽  
Moderately Resistant ◽  
Resistant Genotypes

The influence of inoculation techniques on induction of post-infection ethylene production in susceptible and resistant genotypes of bean (Phaseolus vulgaris) inoculated with the kappa race of Colletotrichum lindemuthianum was studied. Three inoculation methods (brushing, dipping and spraying) of excised leaves were compared. The brushing technique caused both the highest ethylene production at 120 h after inoculation, and better symptom development than dipping and spraying. It was, therefore, adopted to determine the post-infection ethylene production in four inoculated bean genotypes (GLP406 and Kaboon – resistant, GLP636 – moderately resistant; and MDRK – susceptible). Ethylene production increased slightly 24 h after inoculation in all four genotypes, followed by a rapid decline after 48 h. Ethylene production remained low until 120 h after which a sharp rise was observed in genotype MDRK. Increased production, though to a lesser extent, was observed in GLP636. This trend was repeatable and thus may offer an additional physiological marker to bean breeders to screen for resistance to C. lindemuthianum.   

scholarly journals Identification of sources of resistance to anthracnose stalk rot in maize

2016 ◽  
Vol 46 (11) ◽  
pp. 1885-1890
Author(s):  
Alessandro Nicoli ◽  
Laércio Zambolim ◽  
Rodrigo Veras da Costa ◽  
Lauro José Moreira Guimarães ◽  
Fabrício Eustáquio Lanza ◽  
...  
Keyword(s):  
Disease Severity ◽  
Colletotrichum Graminicola ◽  
Sources Of Resistance ◽  
Future Studies ◽  
Stalk Rot ◽  
Experimental Trial ◽  
Two Factors ◽  
Artificial Inoculations ◽  
Primary Measure ◽  
Resistant Genotypes

ABSTRACT: Adoption of resistant cultivars is the primary measure used to control anthracnose stalk rot. The goal of this study was to identify maize-resistant genotypes to anthracnose stalk rot, which are similar to the hybrid 2B710. Experiments were performed at Embrapa Maize and Sorghum experimental fields in Brazil. The first experimental trial evaluated 234 maize lines as well as two commercials hybrids, BRS1010 (susceptible) and 2B710 (resistant). Artificial inoculations were performed with a strain at the blister (R2) phase, and evaluation of disease severity was performed after 30 days. The second experimental trial evaluated 48 maize lines and hybrids, inoculated with two Colletotrichum graminicola strains. In the first trial, eight resistance groups were formed, and the last lines were more resistant, as was the hybrid 2B710, with values between 11.50% and 23.0% of severity. In the second trial, there was an interaction between the two factors, lines and isolates, and the lines often showed the same reaction features as those obtained in the first trial. However, the disease severity was higher for most lines, even when using other isolates. These lines with effective levels of resistance could be used in future studies of inheritance, in programs to develop hybrids, and to identify molecular markers associated with resistance to anthracnose stalk rot in maize.

scholarly journals Biochemical Profiling of Resistant Phenotypes Against Bipolaris oryzae Causing Brown Spot Disease in Rice

2021 ◽  
Vol 3 ◽  
Author(s):  
Benish Ashfaq ◽  
Hafiz M. Imran Arshad ◽  
M. Atiq ◽  
Sumaira Yousaf ◽  
Kamran Saleem ◽  
...  
Keyword(s):  
Disease Severity ◽  
Brown Spot ◽  
Bipolaris Oryzae ◽  
Spot Disease ◽  
Disease Resistant ◽  
Brown Spot Disease ◽  
Significant Difference ◽  
Rice Genotypes ◽  
Moderately Resistant ◽  
Resistant Genotypes

Brown leaf spot disease of rice is a dominant lethal disease, caused by the fungus Bipolaris oryzae. The pathogen is an obligate parasite and causes qualitative and quantitative damage to rice crop. The objective of the present study was to investigate what extent the defense related biochemical compounds reflect the distinct categories of resistance phenotypes in rice against brown spot disease. This was done by determining the concentration of Catalase (CAT), Phenylalanine ammonia-lyase (PAL), Polyphenol oxidase (PPO), Peroxidase (POD), and β-1,3-Glucanase enzymes in resistant, moderately resistant and susceptible rice genotypes. The disease resistant phenotypes in rice line (PARC-7) reflect the higher accumulation of CAT, PAL, PPO, POD, and β-1,3-Glucanase. The pattern of enzyme accumulation was similar in all resistant genotypes. The rice genotypes with moderately resistant phenotypes showed significant difference with respect to the concentration of biochemical defense-related compounds. The difference in accumulation of defense related enzymes reflected the level of disease severity (% leaf area covered) on resistant and moderately resistant genotypes. The susceptible rice genotypes showed the minimum concentration of these enzymes, with the lowest concentrations found in the rice variety Bas-2000 (80% Disease Index). The differential defense response in resistant and susceptible genotypes suggests that these enzymes can be used as biochemical markers for early detection of disease resistant genotypes. The study of enzyme accumulation at different time points and at different levels of disease severity helps to understand the resistance mechanisms against brown spot disease in rice.

scholarly journals Evaluation of Glycine max Germ Plasm for Resistance to Fusarium solani f. sp. glycines

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 741-746 ◽  
Author(s):  
D. S. Mueller ◽  
G. L. Hartman ◽  
R. L. Nelson ◽  
W. L. Pedersen
Keyword(s):  
Sudden Death ◽  
Great Lakes ◽  
Disease Severity ◽  
Fusarium Solani ◽  
Sudden Death Syndrome ◽  
Soybean Plant ◽  
Sources Of Resistance ◽  
Foliar Disease ◽  
Plant Introductions ◽  
Moderately Resistant

Sudden death syndrome, caused by Fusarium solani f. sp. glycines, has caused increased losses in soybean production in recent years. This study was done to identify potential sources of resistance to sudden death syndrome. Using a greenhouse screening procedure, 6,037 soybean plant introductions (PIs) were compared with a susceptible check, Great Lakes 3302, and two moderately resistant checks, PI 520.733 and PI 567.374, for resistance to sudden death syndrome. Only 57 PIs had foliar disease ratings that were not significantly different from PI 567.374 (P ≤ 0.05) 3 weeks after inoculation. Six PIs had lower ratings than PI 567.374 at 4 weeks after inoculation, while none had lower area under the disease progress curve (AUDPC) values. When comparing the PIs to PI 520.733, 209 PIs had foliar disease ratings not significantly different from PI 520.733 (P ≤ 0.05) 3 weeks after inoculation. Eight PIs had significantly lower disease severity ratings 4 weeks after inoculation, and 38 PIs had significantly lower AUDPC values than PI 520.733. Additionally, root lesion lengths were measured 4 weeks after inoculation and ranged from 25.2 to 41.5 mm for all the PIs; none of the entries had smaller lesion lengths than the susceptible check Great Lakes 3302. The correlation between lesion length and disease foliar severity rating was not significant. There also were no plant morphological characteristics (i.e., flower color or seed coat color) associated with higher sudden death syndrome foliar symptoms. Eighteen PIs previously identified as moderately resistant with differing agronomic traits were inoculated with five different isolates of Fusarium solani f. sp. glycines. Results indicated that resistance in these 18 PIs was effective against all five isolates of Fusarium solani f. sp. glycines. Isolate Mont-1 caused the greatest disease severity ratings. These PIs that exhibited low foliar severity ratings may provide new sources of resistance for the development of new sudden death syndrome-resistant lines and cultivars.

Sources of resistance to Fusarium wilt and root-knot nematode in indigenous chickpea germplasm

2012 ◽  
Vol 10 (3) ◽  
pp. 258-260 ◽  
Author(s):  
Mohar Singh ◽  
Z. Khan ◽  
Krishna Kumar ◽  
M. Dutta ◽  
Anju Pathania ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Rating Scale ◽  
Resistance Breeding ◽  
Practical Method ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Chickpea Wilt ◽  
Breeding Programmes ◽  
Race 1 ◽  
Moderately Resistant

Fusarium wilt caused by Fusarium oxysporum, Schlecht. emend. Snyd. & Hans. f. sp. ciceri is prevalent in most chickpea-growing countries and is a major devastating disease. Host plant resistance is the most practical method of disease management. Indigenous chickpea germplasm reveals a heterogeneous genetic make-up and the response of resistance to wilt is an unexplored potential source for disease resistance. There are 70 indigenous germplasm lines selected on the basis of their agronomic performance and diverse areas of collections in the country. Of these, four accessions had a highly resistant score of 1 and six had a score of 3 using a 1–9 rating scale, indicating their level of resistance to Fusarium wilt (race 4). Other germplasm accessions of chickpea were found to be moderately resistant to highly susceptible disease reaction. Likewise, the same set of germplasm was also screened for Meloidogyne incognita (race 1) using pot culture under controlled condition. Only one accession was found to be resistant to this pest. These resistant gene sources can be utilised effectively for race-specific chickpea wilt and root-knot resistance breeding programmes.

scholarly journals Evaluation of a Diverse, Worldwide Collection of Wild, Cultivated, and Landrace Pepper (Capsicum annuum) for Resistance to Phytophthora Fruit Rot, Genetic Diversity, and Population Structure

2015 ◽  
Vol 105 (1) ◽  
pp. 110-118 ◽  
Author(s):  
R. P. Naegele ◽  
A. J. Tomlinson ◽  
M. K. Hausbeck
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Phytophthora Capsici ◽  
The United States ◽  
Fruit Rot ◽  
Sources Of Resistance ◽  
Plant Introductions ◽  
Genetic Clusters ◽  
Commercial Breeding ◽  
Moderately Resistant

Pepper is the third most important solanaceous crop in the United States and fourth most important worldwide. To identify sources of resistance for commercial breeding, 170 pepper genotypes from five continents and 45 countries were evaluated for Phytophthora fruit rot resistance using two isolates of Phytophthora capsici. Genetic diversity and population structure were assessed on a subset of 157 genotypes using 23 polymorphic simple sequence repeats. Partial resistance and isolate-specific interactions were identified in the population at both 3 and 5 days postinoculation (dpi). Plant introductions (PIs) 640833 and 566811 were the most resistant lines evaluated at 5 dpi to isolates 12889 and OP97, with mean lesion areas less than Criollo de Morelos. Genetic diversity was moderate (0.44) in the population. The program STRUCTURE inferred four genetic clusters with moderate to very great differentiation among clusters. Most lines evaluated were susceptible or moderately susceptible at 5 dpi, and no lines evaluated were completely resistant to Phytophthora fruit rot. Significant population structure was detected when pepper varieties were grouped by predefined categories of disease resistance, continent, and country of origin. Moderately resistant or resistant PIs to both isolates of P. capsici at 5 dpi were in genetic clusters one and two.

Genetic diversity among potato species as revealed by phenotypic resistances and SSR markers

2013 ◽  
Vol 11 (2) ◽  
pp. 131-139 ◽  
Author(s):  
D. Carputo ◽  
D. Alioto ◽  
R. Aversano ◽  
R. Garramone ◽  
V. Miraglia ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Sources Of Resistance ◽  
Wild Potato Species ◽  
Resistance Response ◽  
Potato Species ◽  
Average Value ◽  
Ssr Analysis ◽  
Efficient Breeding ◽  
Resistant Genotypes

The evolutionary diversity of wild potato species makes them excellent materials for improving the narrow genetic basis of the cultivated potato Solanum tuberosum. Understanding their genetic diversity is important not only to choose the best parents for breeding, but also to design proper crossing schemes and selection strategies. The objectives of this study were to determine the resistance response to Ralstonia solanacearum, Potato virus Y and low temperatures of 21 clones of 12 potato species, and to determine their genetic diversity through simple sequence repeat (SSR) markers. Sources of resistance have been found for all the investigated traits, with high resistance variability not only between but also within species. Combined resistances were also identified, with positive implications for efficient breeding. SSR analysis allowed the detection of 12 loci and 46 alleles across all genotypes, with an average value of 3.8 alleles per locus. Both unique and rare alleles useful for marker-assisted selection were found. SSR-based cluster analysis revealed that resistant genotypes were distributed among all clusters, suggesting that genetically different resistant genotypes were identified. The information obtained in this study is discussed from a breeding perspective.

Sign in / Sign up

Export Citation Format

Share Document