Sequence Analysis of the Ribosomal DNA Spacer Region of Pyrenophora spp.; Evaluation of its Potential for PCR Detection in a Seed Health Test

Author(s):  
Elisabeth A. Stevens ◽  
Blakemore J. A. Emily ◽  
James C. Reeves
Plant Disease ◽  
2004 ◽  
Vol 88 (6) ◽  
pp. 633-640 ◽  
Author(s):  
J. K. Pataky ◽  
C. C. Block ◽  
P. M. Michener ◽  
L. M. Shepherd ◽  
D. C. McGee ◽  
...  

Two sets of experiments were done to examine whether seed-treatment chemicals affected the ability of an enzyme-linked immunosorbent assay (ELISA)-based seed health test to detect Erwinia stewartii. The chemicals evaluated included Actellic, Apron, Captan, Cruiser, Gaucho, Maxim, Poncho, Thiram, and Vitavax in 11 seed-treatment combinations. In one experiment, seed-treatment chemicals were evaluated quantitatively in a critical region of ELISA absorbance values near 0.5 using maize seed that were spiked with uniform quantities of a liquid suspension of E. stewartii. The number of bacteria in each sample was estimated from ELISA absorbance values using standard curves. Log CFU of E. stewartii per sample were not significantly different among the untreated control and the 11 seed treatments compared with Tukey's Studentized Range Test (P = 0.05). Means of log CFU/ml for all treatments were tightly clustered around 5.70 which corresponded to an absorbance value of 0.440 and a bacterial population of about 500,000 CFU/ml. In a second set of experiments, seed treatment chemicals were evaluated based on qualitative decisions that resulted from the ELISA-based seed health test of seed lots of Jubilee and A632 infected with E. stewartii. The number of negative samples was not substantially greater than expected based on binomial probabilities except for samples of Captan/Vitavax-treated A632, which we considered to be a type I error. The mean absorbance values of positive samples ranged from 1.42 to 1.72 for A632 and from 1.51 to 1.91 for Jubilee and did not differ significantly among the seed treatments. There was no consistent evidence from these experiments that fungicide or insecticide seed treatments interfered with the sensitivity of the ELISA or altered low (e.g., 0.5) or high (e.g. 1.4 to 1.9) absorbance values. The ability of the ELISA-based seed health test to detect E. stewartii in maize seed was not affected by these seed treatments.


2016 ◽  
Vol 29 (1) ◽  
pp. 66-75 ◽  
Author(s):  
CÁSSIO JARDIM TAVARES ◽  
PATRÍCIA CARDOSO FERREIRA ◽  
ADRIANO JAKELAITIS ◽  
JULIANA DE FÁTIMA SALES ◽  
OSVALDO RESENDE

ABSTRACT: The objective of this research was to evaluate the effects of using different herbicides as desiccants in pre-harvest and the effects of storage on the physiological and sanitary quality of azuki bean seeds (Vigna angularis Willd). The experiment was arranged in a randomized complete block design in a split plot scheme, with four replications. Four herbicides were tested: paraquat (400 g a.i. ha-1), glufosinate ammonium (400 g a.i. ha-1), glyphosate (720 g a.i. ha-1), flumioxazin (30 g a.i. ha-1) and a control without herbicide application. In the subplots seed quality was tested in two evaluation periods: at harvest and six months after harvest. Desiccant was applied when the azuki beans were physiologically mature. We assessed the physiological and sanitary quality of the seeds using a vigour and seed health test. The use of glyphosate resulted in a higher incidence of abnormal seedlings and reduced size and weight of the seedlings. With paraquat and flumioxazin the physiological quality was maintained and there was reduced pathogen infestation in the seeds six months after harvest. Storage affected the physiological quality of the azuki bean seeds.


2012 ◽  
Vol 5 (1) ◽  
pp. 113-116
Author(s):  
A Sultana ◽  
AQMB Rashid

An experiment was conducted under in-vitro condition to determine the effect of wheat seed categories such as healthy looking, blackpointed and shriveled as affected by Bipolaris sorokiniana on the germination of wheat seeds. The work was done in the   laboratory of Seed Pathology Center, Bangladesh Agricultural University, Mymensingh during 2010-11. The highest prevalence   65%) of B. sorokiniana was recorded in shriveled seeds, (42%) was recorded in blackpointed seeds, and (30%) was associated  with healthy looking seeds. The pathogen was responsible for the highest germination failure (87%) found in the category of   shriveled seeds and then (35%) was found in blackpointed seeds while the healthy looking seeds showed (24%) germination  failure. The result suggests that, the shriveled and blackpointed seed samples must be rejected, and after proper seed health test in an only the healthy looking seeds may be recommended for sowing through proper seed treatment. DOI: http://dx.doi.org/10.3329/jesnr.v5i1.11563 J. Environ. Sci. & Natural Resources, 5(1): 113 - 116, 2012


2016 ◽  
Vol 27 (1) ◽  
pp. 48-56
Author(s):  
L Naher ◽  
MA Ali ◽  
S Sheheli

Farmers of our country are not aware about seed treatment for controlling seed borne fungi. Seeds of 3 rice varieties viz. BR11, BRRI dhan30 and BRRI dhan33 were collected from farmers houses of Gopalpur, Tangail. Three seed treating fungicides viz. vitavax 200 vitavax 200 (0.25%), thiovit (0.25%) and cupravit (0.25%) were used. Collected seed samples were tested by dry inspection and blotter method. The highest and the lowest germination were recorded in seed samples of BRRI dhan30 (90%) and BRRI dhan33 (75%). After seed treatment the highest and the lowest germination were recorded in seed samples of BRRIdhan30, BRRI dhan33 (100) treated by vitavax 200 (0.25%) and BR11 (80%) in control. Seed health test by blotter method revealed seed borne fungi belonging to six genera viz. Bipolarisoryzae (2.5 to 8.53%), Alternariapadwickii (5.3 to 13.35%), Fusariummoniliforme (11.66 to 21.67%), Fusariumoxysporum (1.25 to 4.35%), Curvularialunata (1.95 to 7.5%) and Aspergillusspp (1.75 to 6.54%) were encountered. Bur after seed treatment remarkable improvement viz. Bipolarisoryzae (0.15 to 3.75%), Alternariapadwickii (0.0 to 3.0%), Fusariummoniliforme (2.16 to 5.83%), Fusariumoxysporum (0.0 to 3.0%), Curvulariaunata (0.0 to 2.56%) and Aspergillusspp (0.0 to 1.5%) were encountered. Vitavax 200 was found most effective against the seed borne pathogens of rice. Nowadays, many botanical extracts such as neem, nishinda, garlic, alamonda and biological agent such as Trichoderma also using as seed treating agent and resulted significant higher germination and plant stand, less disease incidence and higher yield of different crops. So, the farmers should treat their seed before sowing in their field and through this technique they will be more benefited.Progressive Agriculture 27 (1): 48-56, 2016


2020 ◽  
Vol 55 (1) ◽  
pp. 43-53
Author(s):  
E. Gyasi ◽  
C. Kwoseh ◽  
E. Moses

A survey was conducted on the source of planting materials and pre-planting seed treatment practice by pepper farmers in Obenemasi and Ofoase-Kokoben communities in the Ashanti Region of Ghana using a well-structured questionnaire in June, 2011. Seed health test was conducted on 40 farmer-saved pepper seed samples collected from the farmers interviewed using the blotter method in the laboratory. Efficacy of garlic, ginger and neem botanical extracts in managing the seed-borne fungi of pepper seeds was also investigated in this study in-vitro. Results of the questionnaire-based survey indicated that, majority of respondent farmers, about 75% recycled seeds from previous harvest, 20% of respondents also used seeds obtained from friends and 5% obtained their pepper seeds from local markets. Nine genera of fungi including 12 species were identified from the pepper seed samples collected. The three botanical extracts proved effective as Mancozeb in controlling one or more of the test seed-borne fungi. Garlic aqueous extract (60% (w/v)) was effective as Mancozeb in controlling Colletotrichum capsici and Colletotrichum gloesporioides. Ginger aqueous extract (60% (w/v)) was also effective against seed-borne Fusarium and Aspergillus spp. whereas aqueous neem extract (60% (w/v)) was effective in controlling Aspergillus flavus and Aspergillus niger.


2016 ◽  
Vol 3 (3) ◽  
pp. 403-410 ◽  
Author(s):  
Imam Mehedi ◽  
Afia Sultana ◽  
Md Amanut Ullah Raju

Seed health test was done in laboratory to determine the status of seed borne fungi on seeds of five tomato (Lycopersicon esculentum) varieties viz. Manik, Ratan, Roma VF, Kopotakkho and Monirumpuri and their possible control by using plant extracts. A total of 4 genera of 3 species of fungi were recorded where Fusarium oxysporum was the most prevalent and predominant seed borne fungus (25.60%). Other three fungal species are Aspergillus sp. of Aspergillus flavus (21.70%) and Aspergillus niger (11.11%) and Cladosporium sp. (13.49%). Tomato seeds were treated with different plant leaf extracts namely Mahogany, Mehendi and Allamanda with different doses viz. 1:1, 1:2 and 1:3 to control the seed borne fungi. In treated seeds, germination was ranged from 72-82% which was 68% in controlled condition. Among the doses of three botanicals, Mahogany, Mehendi and Allamonda extract @ (1:1 w/v) showed significant performance in controlling seed borne fungi and germination of tomato seeds. Among the three botanicals, Mahogany @ (1:1 w/v) was found the best treatment regarding percent reduction of seed borne infection.Res. Agric., Livest. Fish.3(3): 403-410, December 2016


2019 ◽  
Vol 13 ((04) 2019) ◽  
pp. 635-641
Author(s):  
Mônica Shirley Brasil dos Santos e Silva ◽  
Antônia Alice Costa Rodrigues ◽  
Erlen Keila Candido e Silva ◽  
Anna Christina Sanazário de Oliveira ◽  
Leonardo de Jesus Machado Gois de Oliveira ◽  
...  

The objective of the present study was to assess the seed health quality, quantification of seed-seedling pathogen transmission and the effect of plant extracts in reducing plant pathogens in the seeds of the tomato varieties San Marzano and Ipa 6. For the seed health, the samples were disinfested, plated and assessed after seven days, according to the Brazilian Seed Analysis Rule. For the transmission rate, 12 trays were prepared with 100 seeds each and assessed at 7, 14 and 21 d.a.s. (days after seeding) using 100 seedlings. The plant (main root, stalk and leaves) tissues were plated in PDA culture medium and assessed after seven days of incubation. Aqueous extracts were prepared from cinnamon, basil, neem and eucalyptus with 0.5% concentration and the seeds were immersed in each solution for 10 minutes. Then, they plated and assessed after seven days. The health test showed that biggest incidences of Aspergillus fumigatus (26 %) and Aspergillus flavus (26 %) were occurred in the seeds of the varieties Ipa 6 and San Marzano, respectively. The fungi A. flavus, A. fumigatus, A. niger, R. stolonifer and Curvularia sp. were detected in quantification of transmission in the seeds of the two tomato varieties. The treatment with basil extract resulted in the least fungus incidence in the transmission quantification of ‘San Marzano’ tomato seeds, while on Ipa 6 seeds the eucalyptus treatment performed better. The interference of treatments was not observed in tomato seed germination. However, there was decrease in incident of pathogens in seeds treated with the plant extracts and different effects was observed based on type and species of the pathogen.


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