VARIABILITY WITHIN ISOLATES OF VERTICILLIUM ALBO-ATRUM FROM POTATO

1961 ◽  
Vol 41 (3) ◽  
pp. 487-492 ◽  
Author(s):  
D. B. Robinson
Keyword(s):  
Irish Cobbler ◽  
Prince Edward Island ◽  
Growth Habit ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Verticillium Albo Atrum

A monospore analysis of fresh isolates of Verticillium albo-atrum Reinke & Berthold from eight locations and six varieties of potato in Prince Edward Island, showed that, with one exception, the mass isolates were composed of morphologic forms distinguishable in growth habit and in capacity to form dark resting mycelium. One chief component, resembling the parent form, was present in all isolates. Pathogenicity trials in the greenhouse showed that the monospore forms differed in virulence and that virulence was not associated with the capacity to form dark, resting mycelium. Some monospore forms were avirulent, and one series was found that was equally pathogenic on both the highly susceptible variety Irish Cobbler and the field resistant variety Houma.

scholarly journals Resistance Response of Maize Germplasm to Downy Mildew [Peronosclerospora philipinensis]

2018 ◽  
Vol 24 (1) ◽  
pp. 43
Author(s):  
Syahrir Pakki ◽  
Mappaganggang Mappaganggang
Keyword(s):  
Downy Mildew ◽  
Block Design ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Average Intensity ◽  
Standard Score ◽  
Resistance Response ◽  
Maize Germplasm ◽  
Randomized Block Design ◽  
Moderately Resistant

<p>Two experiments to study responses of resistance of maize germplasm to downy mildew (Peronosclerospora philipinensis) have been conducted. Both experiments were arranged in randomized block design with two replication. The treatments in each experiment (2014 and 2016) were 70 maize accessions. The accessions were planted in planting distant of 75 cm × 20 cm, in 5 m rows, resulting in 20 plants per row. In every 10 rows, two check varieties were planted, i.e. one susceptible and one resistant variety. Ten days prior to planting, the soil was fertilized with mixed fertilizers consisted of urea, ZA, SP36, and KCl at a dose of 100, 100, 100, and 100 kg/ha, respectively. Fertilization II and III was given at 30 days after planting, and 45 days after planting with a dose of 100 kg urea/ha. As a source of inoculum downy mildew, around the repeated plot was planted with varieties Anoman variety (susceptible variety) that was inoculated with a suspension of downy mildew pathogen. Observation was conducted at 25, 35, and 55 days after planting, with the standard score of resistant to downy mildew, followed: 0–10% = resistant, 11–25% = moderately resistant, 26–50% = moderately susceptible, &gt;50% = susceptible. The result of the experiments showed that there were 5 accessions resistant to downy mildew (P. philipinensis), i.e. CML 440×MR4-9-30-3, 664, 60, 572, and 554 with the intensity of downy mildew infection ranged from 5 to 10%. Twelve other accessions were classified as moderately resistant, i.e. CML 440×MR4-9-98-2, 440×MR4-9-98-4 CML, CML 440×MR4-9-124-1, 66, 71, 319, 108, 73, 48, 105, 554, and 682 with intensity of infection ranged from 13 to 25%. At the same experiments, the average intensity of downy mildew infection on susceptible check varieties reached 100 percent.</p>

Transcriptome analysis of scions grafted to potato rootstock for improving late blight resistance

2020 ◽  
Author(s):  
Yuexin Li ◽  
Degang Zhao
Keyword(s):  
Disease Resistance ◽  
Late Blight ◽  
Protein Kinases ◽  
Molecular Mechanisms ◽  
Late Blight Resistance ◽  
Potato Late Blight ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Blight Resistance ◽  
Expression Levels

Abstract Background: Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms.Results: A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. These genes included late blight response genes encoding calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs. When Favorita was used as the rootstock, the expression levels of the late blight response genes were not up-regulated in the Qingshu 9 scion, but the expression levels of the genes related to proline metabolism, fatty acid chain elongation, and diterpenoid biosynthesis pathways were down-regulated. Resistance results showed that self-grafting of the susceptible variety and grafting with the resistant variety as the rootstock increased the resistance of the susceptible scion to late blight. However, the resistance was stronger after grafting with the resistant variety as the rootstock. Using the susceptible variety as the rootstock decreased the late blight resistance of the resistant scion.Conclusions: Our results showed that changes to the expression of disease resistance genes in the scion after grafting are associated with late blight resistance. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.

scholarly journals Changes in Protein Composition in the Grain and Malt after Fusarium Infection Dependently of Wheat Resistance

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 112 ◽  
Author(s):  
Spanic ◽  
Horvat ◽  
Drezner ◽  
Zdunic
Keyword(s):  
Molecular Weight ◽  
Grain Yield ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Low Molecular Weight ◽  
Protein Distribution ◽  
Glutenin Subunits ◽  
Wheat Grains ◽  
Fusarium Infection ◽  
The Impact

The grain yield, as well as the quality and safety of the wheat grains and corresponding malt can be compromised by Fusarium spp. infection. The protein content of the grain affects the chemical composition and enzyme levels of the finished malt. The malting industry demands varieties with good malting and brewing performance, as well as good agronomic performance and disease resistance. The best method of disease control is breeding and selection for resistant varieties. Due to higher requirements for malting wheat worldwide, the goal of this investigation was to explore changes in protein distribution in wheat grains and corresponding malt, which are under higher pressure of Fusarium head blight (FHB) infestation in field conditions. The present study provides new knowledge on the impact of the FHB on the distribution of protein components of naturally Fusarium-infected (control) and Fusarium-inoculated wheat varieties in the grain and the corresponding malt in two consecutive years (2015/2016 and 2016/2017). The results showed that Fusarium infection of the susceptible variety Golubica, decreased total glutenins (5.9%), and both high and low molecular weight glutenin subunits (2.5% and 3.5%, respectively) in wheat grains, compared to control, in 2016. In contrast, gliadins and α-gliadins increased significantly (+7.6% and +5.1%, respectively) in the same variety. Wheat grains of the more resistant variety Vulkan showed an increase of the total glutenins content (+4.3%), and of high and of low molecular weight glutenin subunits (+1.2% and +3.2%, respectively) after Fusarium-inoculation, compared to naturally infected grains in 2016. Susceptible variety Golubica increased total glutenins (+9.1%), and both high and low molecular weight glutenin subunits (+3.5% and +5.6%, respectively) after Fusarium-inoculation in wheat malt, compared to naturally infected malt in 2016. In 2017, when disease pressure was higher than in 2016, there was a tendency in all varieties to increase gliadins and its sub fractions after malting, and to decrease glutenins and its sub fractions in Fusarium-inoculated treatment. In conclusion, FHB dramatically depressed grain yield (up to 37%) and quality (glutenins and high molecular weight subunits) in the susceptible Fusarium variety, which makes it inconvenient for malting.

scholarly journals Screening Camelia sinensis Germplasm Against Grey Leaf Blight of Tea

2017 ◽  
Vol 5 (4) ◽  
pp. 123 ◽  
Author(s):  
Asma Akbar ◽  
Gul Shad Ali ◽  
Brian Pearson ◽  
Farrukh Hamid ◽  
Sonia Sumreen
Keyword(s):  
Dry Weight ◽  
Susceptible Variety ◽  
Leaf Blight ◽  
Resistant Variety ◽  
Lesion Diameter ◽  
Leaf Weight ◽  
Number Of Leaves ◽  
Tea Plants ◽  
Blight Disease ◽  
Grey Blight

Grey blight is a foliar disease of tea plants (Camellia sinensis) caused by Pestalotiopsis. The grey blight pathogen was isolated from infected leaves of tea plants in the National Tea and High Value Crop Research Institute (NTHRI), Shinkiari, Khyber Pakhtunkhwa, Pakistan. Eight different varieties, Indonesian, Roupi, Jue King, P-5, P-3, Qi man, Chuy and P-1, were investigated for yield loss and resistance against the grey blight disease. All varieties displayed considerably different levels of resistance to Pestalotiopsis (p<0.05). The most resistant variety was Indonesian, which showed the lowest number of lesions (1.5 leaf-1) and the smallest lesion diameter (3.0 cm), whereas the most susceptible variety was P-1 which showed the highest number of lesions (3.83 leaf-1) and the largest lesion diameter (15.0 cm). The grey leaf blight pathogen significantly affected biomass and dry matter of the tested varieties. Compared to non-inoculated control, inoculation with Pestalotiopsis reduced the number of leaves by 40% (p<0.05), fresh leaf weight by 31% (p<0.05) and dry leaf weight by 59% (p<0.05). Whereas, the Indonesian variety was the least affected showing only 11% (p<0.05), 19% (p<0.05), and 28% (p<0.05) reduction in number of leaves, fresh weight and dry weight, respectively, over control. These results showed that Pestalotiopsis significantly reduced tea yield and that this disease can be managed by growing resistant varieties.

scholarly journals Systematic Analysis and Functional Validation of Citrus Pectin Acetylesterases (CsPAEs) Reveals that CsPAE2 Negatively Regulates Citrus Bacterial Canker Development

2020 ◽  
Vol 21 (24) ◽  
pp. 9429
Author(s):  
Qiang Li ◽  
Jia Fu ◽  
Xiujuan Qin ◽  
Wen Yang ◽  
Jingjing Qi ◽  
...  
Keyword(s):  
Susceptible Variety ◽  
Resistant Variety ◽  
Potential Candidate ◽  
Bacterial Canker ◽  
Citrus Pectin ◽  
Systematic Analysis ◽  
Canker Disease ◽  
Potential Candidate Gene ◽  
Citrus Bacterial Canker ◽  
Canker Development

The present study was designed to serve as a comprehensive analysis of Citrus sinensis (C. sinensis) pectin acetylesterases (CsPAEs), and to assess the roles of these PAEs involved in the development of citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri (Xcc) infection. A total of six CsPAEs were identified in the genome of C. sinensis, with these genes being unevenly distributed across chromosomes 3, 6, and 9, and the unassembled scaffolds. A subset of CsPAEs were found to be involved in responses to Xcc infection. In particular, CsPAE2 was identified to be associated with such infections, as it was upregulated in CBC-susceptible variety Wanjincheng and inversely in CBC-resistant variety Calamondin. Transgenic citrus plants overexpressing CsPAE2 were found to be more susceptible to CBC, whereas the silencing of this gene was sufficient to confer CBC resistance. Together, these findings provide evolutionary insights into and functional information about the CsPAE family. This study also suggests that CsPAE2 is a potential candidate gene that negatively contributes to bacterial canker disease and can be used to breed CBC-resistant citrus plants.

scholarly journals Biovar Differentiation and Variation in Virulence of Ralstonia solanacearum Isolates Infecting Solanaceous Vegetables

2016 ◽  
Vol 2 ◽  
pp. 22-26 ◽  
Author(s):  
Ram Devi Timila ◽  
Shrinkhala Manandhar
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Negative Impact ◽  
Virulent Strain ◽  
Solanum Melongena ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Slight Variation ◽  
Solanaceae Family ◽  
Moderately Resistant

Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of solanaceous vegetables specially tomato (Lycopersicon esculentum L.) and eggplant (Solanum melongena L.). Experiments were conducted to determine biovar types existing among the strains or isolates of Nepal and variation in virulence in some vegetables belonging to solanaceae family. A total of 39 isolates infecting tomato, eggplant, chilli and potato collected from different parts of Nepal were analyzed for biovar types on the basis of 3 disaccharides and 3 hexose alcohols oxidation test.  Experiments were conducted to determine variation in virulence or aggressiveness of some of the  isolates under  screen house conditions using three host differentials such as Pusa Ruby (susceptible), Bishesh (moderately resistant) and Srijana (resistant) tomato cultivars. Of the 39 isolates, 23 were biovar III, three biovar II, three biovar IV, and one was biovar I. Nine isolates could not be differentiated into any of the five biovars. For breeding and epidemiological purposes it is very important to analyze the variability of aggressiveness. A total of 5 isolates collected from different places were included in the test. Isolates from Bhaktapur was found the most virulent causing wilt in the variety Bishesh (moderately resistant). Other isolates had the negative impact with zero wilt on the differentials used. Isolates from Jungekhola of Dhading district did not induce wilt even on susceptible variety (Pusa Ruby), but exhibited only senescence reaction. The result indicated that there is some slight variation among the isolates tested. Some effective management tactics might be needed in those locations where highly aggressive or virulent strain of bacterial wilt is prevalent, because resistant variety may not be stable in such locations.

THE BIOLOGY OF CANADIAN WEEDS.: 53. Convolvulus arvensis L.

1982 ◽  
Vol 62 (2) ◽  
pp. 461-472 ◽  
Author(s):  
SUSAN E. WEAVER ◽  
WALKER R. RILEY
Keyword(s):  
Reproductive Biology ◽  
Prince Edward Island ◽  
Growth Habit ◽  
Convolvulus Arvensis ◽  
Field Bindweed ◽  
Agricultural Regions ◽  
Rhizome System ◽  
Methods Of Control

Convolvulus arvensis L., field bindweed, is an introduced weed which occurs in the agricultural regions of all provinces of Canada with the exception of Newfoundland and Prince Edward Island. Its twining growth habit and extensive root and rhizome system make it exceptionally difficult to control. It spreads by both seeds and root or rhizome fragments. Details of its morphology, reproductive biology, response to parasites, and methods of control are presented.

Polyamine Modulation by antagonistic bacteria Bacillus subtilis in chickpea during Fusarium oxysporum f. sp. ciceri interaction

2019 ◽  
Author(s):  
K. P. Suthar ◽  
R. M. Patel ◽  
D. Singh
Keyword(s):  
Bacillus Subtilis ◽  
Fusarium Oxysporum ◽  
Seed Treatment ◽  
Plant Defence ◽  
Vegetarian Diet ◽  
Susceptible Variety ◽  
Root Tissue ◽  
Resistant Variety ◽  
Induce Resistance ◽  
Pgpr Traits

Chickpea (Cicer arietinum L.) is pivotal source of protein for vegetarian diet, however, its productivity is adversely affected by wilt disease. Non pathogenic rhizospheric microorganism’s leads to induce resistance and are found to be effective in management of this disease. The polyamines (PAs) content and its metabolism are the key in plant microbial interaction, so the alteration in PAs viz. spermidine (SPD), spermine (SPM) and putresine (PTR) in chickpea by Bacillus substilis isolate K18 (BS-K18) effective antagonist (75%) of Fusarium oxysporum f. sp. ciceri (Foc) and having PGPR traits was analyzed under Foc stress. The higher PAs content was reported in resistant variety (WR-315) compared to susceptible variety (JG-62). The PTR was dominant PA present in chickpea, further overall root tissue reported higher PA content as compared to leaves tissue. The PA content was constitutively improved by B. subtilis seed treatment in resistant and susceptible varieties. The Foc stress leads to induction of PA content in leaves and root tissue, where its content was higher in resistant variety as compared to susceptible variety. The BS-K18 seed treatment under Foc stress leads to induction of PA content as compared to both treatments alone, the SPD and SPM were more induced in leaves and root tissue of susceptible variety whereas PTR was more induces in resistant variety. Overall, polyamines were induced up to 3 DAT then after decline suggest their early role in plant defence mechanism, further PTR was found to be dominating polyamine during chickpea-Foc interaction under BS-K18 treatment. The Bacillus subtilis seed treatment leads to improve wilt tolerance in susceptible var. JG-62 through modulation of PAs, the same mechanism also helped to enhanced effectiveness of resistant var. WR-315.

The influence of host-plant on the development of the adult brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), and its significance in migration

1983 ◽  
Vol 73 (1) ◽  
pp. 117-128 ◽  
Author(s):  
D. E. Padgham
Keyword(s):  
Body Weight ◽  
Host Plant ◽  
Rice Variety ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Residual Body ◽  
Nymphal Stage ◽  
Nilaparvata Lugens Stål

AbstractThe development of adults of Nilaparvata lugens (Stål) reared on one susceptible and one resistant variety of rice plants of different ages was compared. Throughout the range of plants tested there was an overall trend for the newly moulted adult to synthesise and store a reserve of lipid and to lose most of the stored glycogen accumulated during the nymphal stage. N. lugens has two wing morphs, and whilst lipid deposits were greatest in the macropterous ‘migrant’ males, in females it was the brachypterous ‘reproductive’ insects that had the highest lipid deposits and also the greatest residual body weight. However, because of their lower body weight, the macropterous females had the greater percentage of lipid. Both flight willingness and the percentage of macropterous females showing flight-orientated physiological development increased with the age of the host-plant. Both survival and migration potential were lower in insects reared on the resistant rice variety compared to those reared on the susceptible variety. The pattern of post-flight resynthesis of fuels suggests that more than one major migration is unlikely.

scholarly journals Pathogen-induced callose and phenolic compounds accumulation in winter wheat seedlings

2018 ◽  
Vol 76 (2) ◽  
pp. 66-71
Author(s):  
O. Boboshko ◽  
O. Panyuta ◽  
O. Artemenko ◽  
N. Taran ◽  
V. Emelyanov
Keyword(s):  
Phenolic Compounds ◽  
Winter Wheat ◽  
Plant Cell Wall ◽  
Susceptible Variety ◽  
Causal Agent ◽  
Resistant Variety ◽  
Protective Mechanisms ◽  
Wheat Seedlings ◽  
Protective Reaction ◽  
Genetically Determined

Callose and/or phenolic compounds accumulation, which leads to the plant cell wall reinforcement in the places of the host plant and pathogen contact, is one of the first plants reactions on to the pathogen. The local protective reaction causes systemic protective mechanisms that cover the entire plant organism. The purpose of the work was determination of callose and phenolic compounds content in winter wheat seedlings of Myronivska 808 and Renan varieties as constitutional and induced by the eyespot causal agent in the range of their titres active concentrations and comparison of these substances accumulation in time. Callose determination was carried according to the modified Kauss et al. method. Phenoliccompounds quantificationassaywas basedon Folin-Ciocalteu method. The content of constitutional and pathogen-induced callose and phenolic compounds in the winter wheat seedlings of Myronivska 808 and Renan varieties was determined. The higher content of constitutional callose and phenolic compounds at the initial stages of vegetation was established in the wheat seedlings of relatively resistant variety Renan than in the seedlings of the susceptible variety Myronivska 808, which is related with genetically determined resistance of this variety to the eyespot causal agent. More intensive pathogen-induced accumulation of callose was observed in wheat seedlings of Myronivska 808 variety, but this did not affect the overall effectiveness of protection against pathogen. The highest pathogen-induced callose accumulation in wheat seedlings of a relatively resistant variety Renan was under inoculum concentration 104 CFU/ml and in seedlings of the susceptible variety Myronivska 808 – 102 CFU/ml. It has been shown that the higher content of constitutional callose and phenolic compounds and their intensive accumulation under infection in the wheat seedlings of Renan variety, is a determinative factor of the resistance to the eyespot causal agent.

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