scholarly journals Exploring of bacterial blight resistance in landraces, mining of resistant gene(s) and genetic divergence of resistant germplasm through molecular markers and quantitative traits.

2021 ◽  
Author(s):  
Touhidur Rahman Anik ◽  
Sheikh Arafat Islam Nihad ◽  
Md. Al-Imran Hasan ◽  
Mohammad Ahasan Hossain ◽  
Md. Mamunur Rashid ◽  
...  
Keyword(s):  
Genetic Similarity ◽  
Bacterial Blight ◽  
Quantitative Traits ◽  
Molecular Study ◽  
Issr Markers ◽  
Morphological Data ◽  
Pathogenicity Test ◽  
Resistant Varieties ◽  
Wide Range ◽  
Moderately Resistant

Bacterial blight, one of the oldest and severe diseases of rice poses a major threat towards global rice production and food security. Thereafter, sustainable management of this disease has given paramount importance globally. In the current study, we explored 792 landraces to evaluate their disease reaction status against three highly virulent strains ( BXo69 , BXo87 and BXo93 ) of Xanthomonas oryzae pv . oryzae ( Xoo ). Subsequently, we intended to identify the possible candidate resistant ( R ) genes responsible for the resistant reaction using six STS markers correspond to Xa4 , xa5 , Xa7 , xa13 , Xa21 and Xa23 genes and finally, we evaluated morphological and molecular diversity of the potential bacterial blight resistant germplasm using quantitative traits and ISSR markers. Based on pathogenicity test, a single germplasm was found as highly resistant while, 33 germplasm were resistant and 40 were moderately resistant. Further molecular study on these 74 germplasm divulged that 41 germplasm carried Xa4 gene, 15 carried xa5 gene, 62 carried Xa7 gene, 33 carried xa13 gene, and 19 carried Xa23 gene. Only a single germplasm consisted of Xa21 gene. Interestingly, we found a wide range of gene combinations ranged from 2 to 4 genes among the germplasm resistant to bacterial blight and G3 genotype (Acc. No. 4216; highly resistant) having Xa4 , Xa7 , xa13 , Xa21 and G43 genotype (Acc. No. 1523; resistant) having Xa4 , xa5 , xa13 and Xa23 gene combination being the most effective against all the Xoo strains. Nonetheless, UPGMA dendrogram and heatmap analysis based on quantitative traits identified two important clusters viz. cluster-III and cluster-VIII with multiple desired traits However, genetic similarity based on ISSR marker data pointed out 3 germplasm, namely, G20 (Acc. No. 4004; contained Xa4, Xa7, xa13 genes), G17 (Acc. No. 3981; contained Xa7, xa13 genes) and G6 (Acc. No. 991; contained Xa4, Xa7, xa13, Xa23 genes) having comparatively lower genetic similarity (0.30, 0.37 and 0.38, respectively) with elite variety BRRI dhan28. Notably, Mantle test of molecular and morphological data indicated that there was a positive correlation (r = 0.113) between them.  The outcome of this study would enrich and diversify the rice gene pool and would be useful for the development of durable bacterial blight resistant varieties.

scholarly journals EVALUATION OF AVAILABLE GENETIC RESOURCE AGAINST BACTERIAL BLIGHT OF COTTON IN PAKISTAN

2017 ◽  
Vol 29 (1) ◽  
pp. 63 ◽  
Author(s):  
Muhammad Sajid ◽  
Abdul Rashid ◽  
Muhammad R. Bashir ◽  
Muhammad A. Zeeshan ◽  
Muhammad Abid ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Disease Incidence ◽  
Growth Stages ◽  
Environment Friendly ◽  
Resistant Varieties ◽  
Wide Range ◽  
Blight Disease ◽  
Moderately Resistant ◽  
Selection Of ◽  
Susceptible Response

Bacterial leaf Blight of cotton a major seed borne foliar disease that attacks the crop at all growth stages leading to cause severe losses in conducive environment. To find out best source of resistance against pathogen this research was conducted in the field area Department of Plant Pathology, University of Agriculture Faisalabad. Incidence of bacterial blight of cotton was determined on twenty eight varieties/advanced lines sown in field to determine the resistance resource against the disease. Two years data showed that seventeen varieties (BT-Z-33, BT-S-78, BT-786, BT-A-ONE, BT -282, BT-886, BT-3701, BT-SPECIAL, BT-802, Non Bt-FH 901, BT-92, BT-131, BT-905, BT-SUPPER, Non Bt-MNH 496, Non Bt-FH 1000, and BT-121) expressed moderately resistant response with 21-50 % disease incidence (rating 4). Five varieties viz. Non Bt-FH 207, Non BT-N 112, Non BT-FH 942, Non BT-MNH 6070 and Non Bt-FH 941exhibited moderately susceptible response with 51-70% disease incidence under rating 5. Four varieties namely Non BT-N 814, Non Bt-FH 900, Non BT-ANMOL and Non Bt-FH 2015 showed susceptible response with 71-80% disease incidence (rating 6) while Non BT-REDACOLA and Non BT-C 26 expressed highly susceptible response with disease incidence 81-100% rating 7 against bacterial blight disease of cotton. Results indicate that a wide range of resistant resource is present in Pakistan against the disease. The selection of diverse germplasm/resistant varieties through screening is the most efficient, environment friendly and economical management strategy for farmers against this disease.

The control of bacterial blight in rain-grown cotton. II. Some effects of infection on growth and yield

1965 ◽  
Vol 65 (1) ◽  
pp. 29-40 ◽  
Author(s):  
M. H. Arnold
Keyword(s):  
Bacterial Blight ◽  
Susceptible Variety ◽  
Growth And Yield ◽  
Crop Loss ◽  
Seed Cotton ◽  
The Third ◽  
Seed Dressing ◽  
Resistant Varieties ◽  
Series Of Experiments ◽  
Moderately Resistant

Three series of experiments are described from which minimum estimates of crop loss caused by bacterial blight were obtained. In the first two, the estimates were derived from seed-dressing trials, and in the third, seed dressing was used in conjunction with resistant varieties.Losses amounted to as much as 354 ± 39 lb. seed cotton/acre for a susceptible variety but could be reduced both by seed dressing and by using resistant varieties. The effectiveness of resistance in moderately resistant varieties varied from one season to the next, an effect comparable with the genotype-environment interactions previously described for reactions to inoculation.

scholarly journals First Report of Nigrospora oryzae Causing Leaf Spot of Cotton in China

Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1379-1379 ◽  
Author(s):  
L. X. Zhang ◽  
S. S. Li ◽  
G. J. Tan ◽  
J. T. Shen ◽  
T. He
Keyword(s):  
Leaf Spot ◽  
Morphological Characteristics ◽  
Morphological Data ◽  
Its Sequence ◽  
Pathogenicity Test ◽  
First Report ◽  
Wide Range ◽  
Cotton Plants ◽  
Symptomatic Leaf ◽  
Nigrospora Oryzae

Cotton (Gossypium hirsutum L.) is widely cultivated for the important economic value of the fiber. In the summer of 2011, a leaf spot of cotton plants cv. Wanza40 was observed in 11 fields (total of about 4 ha) in Qianshan County in southwest Anhui Province, China. Approximately 30% of the plants in each field were symptomatic. Affected plants exhibited brown to reddish, irregular foliar lesions, each with a brown border near the vein of the leaves. A sign of fungal infection was a dark leaf mold observed on lesions on the abaxial surface of leaves. Sections of symptomatic leaf tissues were surface-sterilized (in 75% ethanol for 30 s, then 1% NaOCl for 1 min), rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). A fungus consistently recovered from symptomatic leaf samples produced colonies that were initially white and then became grayish brown with the onset of sporulation. Black, spherical to subspherical, single-celled conidia (10 to 12 × 14 to 16 μm) were borne on a hyaline vesicle at the tip of each conidiophore. Morphological characteristics of the fungus were similar to that of Nigrospora oryzae (2). The internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) from a representative strain of the fungus, AHC-1, was amplified using the primers ITS1/ITS4 (4) and sequenced (GenBank Accession No. JQ864579). The ITS sequence had 99% identity with >553 bp of the ITS sequence of an N. oryzae isolate (GenBank Accession No. EU918714.1). On the basis of morphological data and ITS rDNA sequence, the isolate was determined to be N. oryzae. A pathogenicity test was performed on detached, young leaves of 4-month-old healthy cotton plants of cv. Wanza40. Six leaves were inoculated by placing a colonized agar piece (5 mm in diameter) from 7-day-old cultures of the fungus on pushpin-wounded leaves. Another six leaves treated with sterile PDA plugs served as a negative control treatment. Leaves were incubated in petri dishes and maintained at 25°C in a growth chamber programmed for 12 hours of fluorescent white light/day. After 5 days, brown to black lesions were observed on all inoculated leaves, whereas no symptoms developed on control leaves. N. oryzae was consistently reisolated from symptomatic leaves but not from the control leaves. N. oryzae is a weak pathogen on a wide range of plants, and has been described as the causal agent of lint rot on cotton (1,3), but to our knowledge this is the first report of N. oryzae causing a leaf spot of cotton in China. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , April 8, 2012. (2) H. J. Hudson. Trans. Br. Mycol. Soc. 46:355, 1963. (3) A. J. Palmatter et al. Plant Dis. 87:873, 2003. (4) T. J. White et al. In: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

scholarly journals GREENBUG RESISTANCE IN OAT ACCESSIONS FROM DAGESTAN AND CAUCASIAN COUNTRIES

2019 ◽  
Vol 180 (3) ◽  
pp. 106-109 ◽  
Author(s):  
E. E. Radchenko ◽  
M. A. Chumakov ◽  
I. G. Loskutov
Keyword(s):  
North Caucasus ◽  
Plant Damage ◽  
The North ◽  
Resistant Varieties ◽  
Wide Range ◽  
Important Pest ◽  
Southern Russia ◽  
Susceptible Control ◽  
Moderately Resistant ◽  
Greenbug Resistance

Background. The breeding of resistant varieties is an effective way to control greenbug Schizaphis graminum Rondani, an economically important pest of oat and other cereals in southern Russia. The insect-host differential interaction necessitates a constant search for new resistance donors.Materials and methods. One hundred and ninety one accessions (mostly landraces) from the Caucasian countries (Armenia, Azerbaijan and Georgia) as well as from the North Caucasus of the Russian Federation (Dagestan) were assessed for greenbug resistance. The Krasnodar (Gulkevichi District) insect population was used in the experiments. The intact plants were uniformly infested with differentaged aphids in the phase of two leaves by shaking insects onto them. When the susceptible control (cv. Borrus) died, the plant damage score was determined using the scale from 0 (no damage) to 10 (91–100% of the leaf surface damaged, plant’s death). The plants with the score of 1–4 points were classified as resistant, 5–8 moderately resistant, and 9–10 susceptible.Results and conclusions. A local oat accession from Georgia (k-4308) was noted for its high insect resistance. Also, heterogeneity of the studied trait was demonstrated by 38 oats forms, most of which were differentiated into two phenotypic classes, and a wide range of plant damage variation was characteristic of 16 accessions. The specific occurrence of resistant forms was the highest among oat landraces from Azerbaijan: two out of five studied accessions (40%) carry resistance genes with a distinct phenotypic manifestation. They are followed by accessions from Georgia (25%), Armenia (17.3%) and Dagestan (13.8%). After selection for resistance, the identified forms can be used in plant breeding.

scholarly journals Antifungal Activity of Propyl Disulfide from Neem (Azadirachta indica) in Vapor and Agar Diffusion Assays against Anthracnose Pathogens (Colletotrichum gloeosporioides and Colletotrichum acutatum) in Mango Fruit

2021 ◽  
Vol 9 (4) ◽  
pp. 839
Author(s):  
Muhammad Rafiullah Khan ◽  
Vanee Chonhenchob ◽  
Chongxing Huang ◽  
Panitee Suwanamornlert
Keyword(s):  
Antifungal Activity ◽  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Colletotrichum Acutatum ◽  
Model Parameters ◽  
Pathogenicity Test ◽  
Agar Diffusion ◽  
Wide Range ◽  
Significant Difference ◽  
Diffusion Assay

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R2, 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.

scholarly journals Combination of nuclear and mitochondrial markers as a useful tool to identify Ctenophthalmus species and subspecies (Siphonaptera: Ctenophthalmidae)

2021 ◽  
Author(s):  
Antonio Zurita ◽  
Cristina Cutillas
Keyword(s):  
Taxonomic Status ◽  
Molecular Study ◽  
Molecular Data ◽  
Point Of View ◽  
Morphological Data ◽  
Molecular Approach ◽  
Nuclear Marker ◽  
Mitochondrial Markers ◽  
Morphological Criteria ◽  
Mtdna Markers

AbstractCtenophthalmus is considered the largest genus within the Order Siphonaptera. From a morphological point of view, only males of this genus can be identified at species and subspecies levels using morphological keys, whereas there are no morphological criteria in order to classify females at these taxonomical levels. Furthermore, the amount of available molecular and phylogenetic data for this genus is quite scarce so far. The main objective of this work was to assess the utility of the combination of nuclear and mitochondrial markers with respect to their ability to differentiate among different subspecies within the Ctenophthalmus genus. With this purpose, we carried out a comparative morphological and molecular study of three different subspecies (Ctenophthalmus baeticus arvernus, Ctenophthalmus nobilis dobyi, and Ctenophthalmus andorrensis catalaniensis) in order to clarify and discuss its taxonomic status. In addition, our study complemented the molecular data previously provided for Ctenophthalmus baeticus boisseauorum and Ctenophthalmus apertus allani subspecies. We sequenced five different molecular markers: EF1-α, ITS1, ITS2, cox1, and cytb. Our results confirmed that morphological data by themselves are not able to discriminate among Ctenophthalmus female taxa; however, the combination of the nuclear marker EF1-α together with mtDNA markers cytb and cox1 constituted a useful taxonomical and phylogenetic tool to solve this issue. Based on these results, we consider that the use of this molecular approach should be gradually used within Ctenophthalmus genus in order to complement its classical taxonomy and clarifying the complex taxonomy of other congeneric species of fleas.

RESISTANCE TO DIEBACK DISEASE CAUSED BY FUSARIUM AND LASIODIPLODIA SPECIES IN CACAO (THEOBROMA CACAO L.) GENOTYPES

2011 ◽  
Vol 48 (1) ◽  
pp. 85-98 ◽  
Author(s):  
RICHARD ADU-ACHEAMPONG ◽  
SIMON ARCHER ◽  
SIMON LEATHER
Keyword(s):  
Biological Sciences ◽  
Theobroma Cacao ◽  
Genotypic Differences ◽  
Sources Of Resistance ◽  
Cross Sectional ◽  
Assessment Scores ◽  
Sahlbergella Singularis ◽  
Wide Range ◽  
Dieback Disease ◽  
Moderately Resistant

SUMMARYFusarium and Lasiodiplodia species invade feeding lesions caused by mirid bugs (Distantiella theobroma [Dist.] and Sahlbergella singularis Hagl.) and inflict serious damage and yield loss to susceptible cacao (Theobroma cacao L.) varieties in West Africa. As it is the fungal invasion rather than the physical feeding injury by mirids that cause dieback and tree death in cacao, a dieback resistance strategy in cacao crop must take into account resistance to these causal agents. Twenty-nine and 15 cacao genotypes were screened in the laboratory and the greenhouse, respectively, for resistance to isolates of Fusarium decemcellulare and Lasiodiplodia theobromae at Imperial College London's Biological Sciences Campus, UK. Resistance was assessed as the size of necrotic lesions, distance of fungal colonisation in the stem and the proportion of seedlings with dieback symptoms. Genotypic differences were found in both laboratory and greenhouse tests among various cacao genotypes, and the clones showed a wide range of disease reactions from highly resistant to very susceptible. The pathogenicity of F. decemcellulare and L. theobromae were similar in this study, which suggests that a breeding programme for controlling one of the pathogens can have benefit against the other. Direct significant correlations (r = 0.7) were obtained between visual dieback assessment scores and the percentage cross-sectional area of stem necrosis. Moreover, the response of inoculated stem segments corresponded to the reaction of intact plants despite the variation in the used methodology. Three cacao genotypes (CATIE 1000, T85/799 and MXC 67) were resistant or moderately resistant to F. decemcellulare and L. theobromae. These genotypes could be useful sources of resistance to both pathogens and other wilt causing pathogens in cacao.

scholarly journals New morphological data and molecular diagnostic of Henneguya friderici (Myxozoa: Myxobolidae), a parasite of Leporinus friderici (Osteichthyes: Anostomidae) from southeastern Brazil

2017 ◽  
Vol 26 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Letícia Poblete Vidal ◽  
José Luis Luque
Keyword(s):  
Body Length ◽  
18S Rdna ◽  
Genetic Similarity ◽  
Morphological Data ◽  
Southeastern Brazil ◽  
Molecular Diagnostic ◽  
Similarity Analysis ◽  
Rdna Sequencing ◽  
The Family ◽  
Gill Filaments

Abstract The myxozoan Henneguya friderici is a parasite of the gills, intestine, kidney and liver of Leporinus friderici, a characiform fish belonging to the family Anostomidae. Forty-two specimens of L. friderici that had been caught in the Mogi Guaçú River, state of São Paulo, were studied. Elongated white plasmodia were found in the gill filaments of 10 host specimens (24%). The mature spores had an ellipsoidal body with polar capsules of equal size and caudal length greater than body length. This study also described 18S rDNA sequencing of H. friderici infecting the gill filaments. This produced a sequence of 1050 bp that demonstrated significant genetic differences with previously described species of Henneguya. Similarity analysis using sequences from species that clustered closest to those produced by this study showed that the species with greatest genetic similarity to H. friderici was H. leporinicola, with 94% similarity.

scholarly journals Analysis of genetic relationships of genotypes of the genus Rosa L. from the collection of Nikita Botanical Gardens using ISSR and IRAP DNA markers

2020 ◽  
Vol 24 (5) ◽  
pp. 474-480
Author(s):  
I. I. Suprun ◽  
S. A. Plugatar ◽  
I. V. Stepanov ◽  
T. S. Naumenko
Keyword(s):  
Genetic Diversity ◽  
Bayesian Methods ◽  
Dna Markers ◽  
Wild Species ◽  
Genetic Similarity ◽  
Genetic Relationships ◽  
Issr Markers ◽  
The Other ◽  
Clustering Methods ◽  
Botanical Gardens

In connection with the development of breeding and the creation of new plant varieties, the problem of their genotyping and identification is becoming increasingly important, therefore the use of molecular methods to identify genetic originality and assess plant genetic diversity appears to be relevant. As part of the work performed, informative ISSR and IRAP DNA markers promising for the study of genetic diversity of the Rosa L. genus were sought and applied to analysis of genetic relationships among 26 accessions of the genus Rosa L. from the gene pool collection of Nikita Botanical Gardens. They included 18 cultivated varieties and 8 accessions of wild species. The species sample included representatives of two subgenera, Rosa and Platyrhodon. The subgenus Platyrhodon was represented by one accession of the species R. roxburghii Tratt. Cultivated roses were represented by varieties of garden groups hybrid tea, floribunda, and grandiflora. The tested markers included 32 ISSRs and 13 IRAPs. Five ISSR markers (UBC 824, ASSR29, 3A21, UBC 864, and UBC 843) and three IRAPs (TDK 2R, Сass1, and Сass2) were chosen as the most promising. They were used for genotyping the studied sample of genotypes. In general, they appeared to be suitable for further use in studying the genetic diversity of the genus Rosa L. The numbers of polymorphic fragments ranged from 12 to 31, averaging 19.25 fragments per marker. For markers UBC 864 and UBC 843, unique fingerprints were identified in each accession studied. The genetic relationships of the studied species and varieties of roses analyzed by the UPGMA, PCoA, and Bayesian methods performed on the basis of IRAP and ISSR genotyping are consistent with their taxonomic positions. The genotype of the species R. roxburghii of the subgenus Platyrhodon was determined genetically as the most distant. According to clustering methods, the representative of the species R. bengalensis did not stand out from the group of cultivated varieties. When assessing the level of genetic similarity among the cultivated varieties of garden roses, the most genetically isolated varieties were ‘Flamingo’, ‘Queen Elizabeth’, and ‘Kordes Sondermeldung’; for most of the other varieties, groups of the greatest genetic similarity were identified. This assessment reflects general trends in phylogenetic relationships, both among the studied species of the genus and among cultivated varieties.

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