SOIL MICROORGANISMS ASSOCIATED WITH FLAX ROOTS

1967 ◽  
Vol 13 (2) ◽  
pp. 199-203 ◽  
Author(s):  
E. A. Peterson ◽  
J. W. Rouatt

The root microflora of Bison flax, resistant to wilt caused by Fusarium oxysporum f. lini, was compared with that of the wilt-susceptible variety Novelty. Plants grown in "disease-free" soil show that the susceptible variety harbors not only the most numerous, but also the most metabolically active bacterial flora on its roots. Generic classification of bacterial isolates shows a higher incidence of more active organisms, represented by Pseudomonas and Flavobacterium on roots of the susceptible crop, whereas the more slowly growing pleomorphic types such as Arthrobacter were most abundant on roots of the resistant variety. Fungi were also more numerous on roots of the susceptible crop, but the generic composition of rhizosphere populations of both varieties was similar to that of the soil itself. Fusarium oxysporum dominated the flora occurring in an active mycelial state on roots of the susceptible variety, whereas F. oxysporum and Phoma sp. were codominants in the active flora of the resistant crop. Tests with other soils showed that dominance of specific genera varies with soil type. The results indicate a selective action on the root microflora, particularly the bacteria, and suggest both quantitative and qualitative differences in root environments of the two flax varieties.

Author(s):  
K. P. Suthar ◽  
R. M. Patel ◽  
D. Singh

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.


1961 ◽  
Vol 39 (1) ◽  
pp. 7-19 ◽  
Author(s):  
A. G. Lochhead ◽  
F. D. Cook

A comparison was made of growth factor requirements and growth factor synthesizing capacity of bacteria from the root surface and from the seeds of flax varieties resistant and susceptible, respectively, to wilt caused by Fusarium oxysporum f. lini. The percentage of bacteria from both root and seed which required growth-promoting substances was greater with the resistant ('Bison') than with the susceptible ('Novelty') variety. On the other hand bacteria capable of synthesizing growth factors were proportionately more abundant with the susceptible variety. The findings indicate a more pronounced rhizosphere effect exerted by the susceptible than by the resistant variety, and point to circumstances that favor a greater accumulation (or 'turnover') of vitamins and related substances at the root surface of susceptible plants.Two strains of Fusarium oxysporum f. lini capable of inducing wilt required no vitamins for growth; thiamine had a depressing effect. Both strains were able to synthesize various growth factors, though in different degree. Culture filtrates of bacteria from roots of the two varieties of flax showed no difference in their effect on growth of Fusarium; however, bacteria from the resistant variety showed somewhat greater ability to depress Fusarium than those from the susceptible. Though the findings do not constitute evidence of any relationship between differences in growth factor relationships to pathogenic potential of Fusarium, they suggest the value of considering growth-promoting substances in studies of the effect of nutrition on the activity of soil-borne pathogens.


2017 ◽  
Vol 40 (04) ◽  
Author(s):  
Y. M. Shukla ◽  
K. P. Suthar

Alterations in b-1,3 glucanase and chitinase activity during host-pathogen interaction were studied in chickpea varieties JCP 27 (resistant) and JG 62 (susceptible) to vascular wilt caused by Fusarium oxysporum f. sp. ciceri race 4. The enzyme activities were analyzed in root, stem and leaf tissues at three stages viz., pre-infection, infection and post-infection in normal and inoculated soil. The b-1,3 glucanase activity in root, stem and leaf tissues of susceptible variety found higher than those of resistant one at all the stages of infection under inoculated condition.. The chitinase activity in root and leaf tissues of susceptible variety was higher than the resistant variety at all infection stages in inoculated soil, whereas in stem tissue the activity level was higher in resistant variety at pre-infection and infection stages. Overall result revealed that b-1,3 glucanase showed higher induction with increase in inoculums pressure of the fungal pathogen, whereas hydrolytic enzyme chitinase was induced only when inoculum pressure of the fungal pathogen was severe.


1996 ◽  
Vol 74 (8) ◽  
pp. 1273-1278 ◽  
Author(s):  
W. C. Mueller ◽  
A. T. Morgham

The reactions of a broadleaf tobacco variety polygenically resistant to Fusarium wilt were compared with a susceptible variety. Symptoms of wilting, yellowing, and eventual death of leaves in the susceptible variety were associated with rapid movement of the fungus through the plant, whereas in the resistant variety the fungus was confined to the lower portion of the plant and symptoms occurred only on the lowermost leaves. The responses in the vascular tissue were similar in both varieties but appeared more intense in the resistant variety. Lipoidal wall coatings and occlusions occurred in the initially infected vessels. Apposition layers containing callose were deposited in the contact cells within 1 day of inoculation. Lipoidal occlusions occurred in the secondarily infected vessels, but apposition layers were not detected in the contact cells. Tyloses were not observed. Resistance is associated with the localization and slower movement of the fungus that is reflected in the observable differences in symptom development. Keywords: contact cells, Nicotiana tabacum, polygenic resistance, vascular occlusion.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kewei Li ◽  
Yijun Liu ◽  
Xiaolong Xie ◽  
Rongxing Zhou ◽  
Bo Xiang

Abstract Background Using effective scolicidal agents intraoperatively is essential to lessen the recurrence rate of hepatic echinococcosis. However, severe hypernatremia may occur after hypertonic saline (HS) has been applied as the scolicidal agent. The aim of this study is to report on pediatric patients with severe hypernatremia after hepatic echinococcus surgery. Methods Patients who presented to West China Hospital between January 2010 and February 2017 were retrospectively analyzed. Children under 16 years with echinococcosis treated by resection were included in the study. Results A total of 26 children were enrolled in this study, including 16 boys and 10 girls with a median age of 8 (2–16). 24 (92.3 %) cases were cystic echinococcosis (CE) and two (7.7 %) were alveolar echinococcosis (AE). According to Clavien-Dindo classification of surgical complications, the complication rate of all 26 patients was 19.2 %, among which three cases belonged to Grade I, one to Grade III b and 1 to Grade IV. Two children encountered severe hypernatremia (sodium: 155.3 mmol/L and 190.0mmol/L). Data showed classic clinical features of severe hypernatremia: profound and persistent bradycardia, hypotension and coma. After treatment, they recovered well without any neurologic sequelae. All patients were followed up regularly for a median time of 38 months (range 4–89 months); the overall disease-free survival was 100.0 %. Conclusions HS irrigation of intra-abdominal echinococcosis may cause acute hypernatremia and severe consequences. Diagnostic suspicion and early intervention are vital tools for avoiding morbidity and mortality.


2018 ◽  
Vol 24 (1) ◽  
pp. 43
Author(s):  
Syahrir Pakki ◽  
Mappaganggang Mappaganggang

<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>


2020 ◽  
Vol 6 (2) ◽  
pp. 29
Author(s):  
GEMBONG DALMADIYO ◽  
CECE SUHARA ◽  
SUPRIYONO SUPRIYONO ◽  
SUDJINDRO SUDJINDRO

<p><strong>Evaluation on the resistance of kenaf accessions (Hibis¬ cus cannabinus /..) to Fusarium oxysporum Schlect</strong></p><p>Resistant variety is one of the most important components controlling of fusarium wilt disease on kenaf caused by Fusarium oxysporum Schlect. To ind out resistant variety an evaluation on kenaf accessions was conducted in the laboratory and screen house of Phytopathology, RITFC, Malang in June-December 1997. The results of the selection on 77 accessions showed that 41 accessions were highly resistant, 1 2 accessions were resistant, 7 accessions were moderate, 12 accessions were susceptible, and 5 accessions were highly susceptible Three resistant and highly resistant accessions were namely 85-9-73, DS/005 H, and FJ/004 He could inhibit F. oxysporum growth about 23.40- 32.43 mm and its discolorisation about 0.0-13.4%.</p>


2020 ◽  
Vol 18 (4) ◽  
pp. 143
Author(s):  
MESAK TOMBE ◽  
DARMAWAN PANGERAN ◽  
TRI SAPTARI HARYANI

<p>ABSTRAK<br />Busuk batang vanili (BBV) yang disebabkan oleh Fusarium<br />oxysporum f.sp. vanillae (Fov) merupakan patogen penting pada vanili dan<br />menyebabkan kerugian besar setiap tahunnya di Indonesia. Jumlah<br />kerugian diperkirakan sebesar 3.000 ton atau sekitar US$ 16 juta.<br />Penelitian dilaksanakan di laboratorium dan rumah kaca Kelti Hama dan<br />Penyakit, Balai Penelitian Tanaman Rempah dan Obat, Bogor pada bulan<br />Februari 2010 sampai Agustus 2010. Tujuan penelitian adalah untuk<br />mengetahui pengaruh formula dengan bahan aktif minyak cengkeh dan<br />serai wangi terhadap penyakit BBV dan dampaknya terhadap kehidupan<br />mikroorganisme tanah. Dalam pelaksanaannya, kegiatan penelitian dilaku-<br />kan dalam 3 tahap yaitu : (1) uji formula in vitro, (2) uji formula in vivo,<br />dan (3) uji dampak formula terhadap mikroorganisme tanah. Percobaan<br />tahap 1, 2, dan 3 masing-masing terdiri atas 10, 6, dan 6 perlakuan,<br />dan.masing-masing disusun menggunakan rancangan acak lengkap dengan<br />3 ulangan. Materi yang dikaji dalam penelitian ini adalah (1) formula<br />dengan bahan aktif minyak cengkeh (formula standar), (2) formula dengan<br />bahan aktif minyak cengkeh dan serai wangi (formula baru), dan (3)<br />fungisida sintetis berbahan aktif mankozeb sebagai pembanding. Hasil uji<br />in vitro menunjukkan bahwa fungisida nabati CS (minyak cengkeh + serai<br />wangi) pada ke 3 tingkatan konsentrasi (terutama konsentrasi 400 ppm)<br />memperlihatkan efektivitas yang tinggi dalam menghambat pertumbuhan<br />miselium dan produksi spora patogen Fov.F117 dibandingkan perlakuan<br />lain dan kontrol. Hasil uji in vivo menunjukkan hal yang sama bahwa<br />fungisida nabati CS memperlihatkan efektivitas yang tinggi dalam<br />menekan intensitas serangan patogen BBV, terutama pada dosis aplikasi 5<br />ml/l. Dampak perlakuan terhadap kehidupan mikroorganisme tanah (fungi<br />dan bakteri) memperlihatkan bahwa penggunaan fungisida sintetis<br />mankozeb menghambat kehidupan mikroorganisme tanah 90-100% jika<br />dibandingkan dengan kontrol. Populasi mikroorganisme tanah pada semua<br />perlakuan fungisida nabati lebih tinggi jika dibandingkan dengan fungisida<br />mankozeb. Populasi mikroorganisme pada aplikasi fungisida nabati pada<br />dosis 5 ml/l tidak berbeda nyata dengan kontrol. Penelitian ini<br />menunjukkan bahwa penggunaan fungisida nabati minyak cengkeh<br />terutama jika dikombinasikan dengan minyak serai wangi mempunyai<br />prospek untuk digunakan dalam pengendalian penyakit BBV dengan<br />interval aplikasi 3-4 minggu sekali.<br />Kata kunci : Vanilla planifolia, Fusarium oxysporum f.sp, vanillae, busuk<br />batang vanili, minyak cengkeh, minyak serai wangi</p><p>ABSTRACT<br />Vanilla stem rot (VSR) disease caused by Fusarium oxysporum f.sp.<br />vanillae (Fov) is an important disease on vanilla and causes severe loss<br />annually in Indonesia. The total annual loss in production due to the VSR<br />was estimated to be 3,000 ton or about US$ 16 million. This research was<br />carried out in the laboratory and green house of Pest and Disease of<br />Research Institute for Spices and Medicinal Crops, Bogor from February<br />2010 until August 2010. The objective of this research was to study the<br />effect of formula using active compounds of clove and citronella oils on<br />the VSR disease and its impact on the survival of soil microorganisms.<br />The research activities were conducted in three stages, namely (1) in vitro<br />formula test; (2) in vivo formula test, and (3) impact test of formula on the<br />soil microorganisms. Materials studied in this research were (1) formula<br />with active compound of clove oil (standard), (2) formula with active<br />compound of clove and citronella oils (new formula), and (3) synthetic<br />fungicide with mancozeb active ingredient as comparison. Every phase of<br />this 3 stage experiment was arranged using completely randomized design<br />with three replicates. First, second, and third phases of the experiment<br />consisted of 10, 6, and 6 treatments, respectively. In vitro test results<br />carried out in the laboratory indicated that botanical formula CS (clove and<br />citronella oils of the three concentration levels, especially on the 400 ppm)<br />showed high effectiveness on inhibiting mycelium growth and spore<br />production of Fov.F117 pathogen compared to other treatments and<br />control. In vivo test in the green house indicated the same result that<br />botanical fungicide CS (clove dan citronella oils) showed high<br />effectiveness in suppressing VSR disease infection intensity, especially on<br />5 ml/l dosage. Application of mancozeb synthetic fungicide inhibited 90 –<br />100% soil microorganism livelihood compared to control. However, the<br />soil microorganism population on all botanical fungicides was higher than<br />on mancozeb fungicide. The microorganism population on the botanical<br />fungicide of 5 ml/l dosage was not significantly different from the control<br />(natural soil with no treatment). This research indicates that aplication of<br />botanical fungicide (combination between clove and citronella oils) with<br />3 - 4 weeks interval is prospectous to control VSR disease.<br />Key words : Vanilla planifolia, Fusarium oxysporum, f.sp. vanillae,<br />vanilla stem rot, clove oil, citronella oil</p>


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