scholarly journals The diversity of fungi colonizing necrotic inflorescence buds of rhododendron (Rhododendron L.)

2013 ◽  
Vol 66 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Małgorzata Żołna ◽  
Barbara Kierpiec-Baran ◽  
Maria Kowalik

<p>The infection of rhododendron (<em>Rhododendron </em>L.) inflorescence buds caused by pathogenic fungi induces its browning, withering, and dieback. The identification of fungi causing the infection of rhododendron inflorescence buds can be a reason for creating new improved cultivars with genetically determined resistance to pathogens. The investigations were carried out in 2010–2011 on the collection of ornamental plants of the Faculty of Horticulture, University of Agriculture in Kraków. The material comprised infected inflorescence buds collected from nine newly bred taxa and one botanical species of rhododendron. 596 colonies of fungi belonging to 31 species were isolated from infected rhododendron inflorescence buds. The dominant species were: <em>Pestalotiopsis sydowiana</em>, <em>Truncatella truncata</em>, <em>Alternaria alternata</em>, <em>Phialophora asteris,</em> and <em>Trichoderma viride</em>, which constituted almost 74% of the isolated fungi population.<em> Boeremia exigua </em>var<em>. exigua</em>,<em> Epicoccum nigrum</em>, <em>Fusarium poae</em>, <em>Mammaria echinobotryoides</em>, <em>Paraphoma chrysanthemicola</em>, <em>Phialophora cyclaminis</em>,<em> Phoma eupyrena</em>, <em>Talaromyces wortmannii</em>, <em>Umbelopsis isabellina</em>, and other fungi were isolated in a lower number.</p><p>The results of mycological analysis confirm the diversity of species colonizing necrotic inflorescence buds of rhododendron.</p>.

PERENNIAL ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 33
Author(s):  
Astuti Arif ◽  
. Syahidah ◽  
Sitti Nuraeni

Fungi have a great diversity and wide distribution at the world. It can be used as the alternative technology for controlling of subterranean termite attack, particularly genus Coptotermes knowned as the wooden destructive organism, by using entomophatogenic fungi. For the purpose of the study, several isolate sources were taken from some locations. The results show that eight numbers of pathogenic fungi was founded by screening and identification of fungi taken from 19 numbers of isolate sources. The pathogenic fungi were Beauveria sp., Penicillium brevicompactum, P. rubrum, Paecilomyces fulvus, Fusarium verticolloides, Pythium sp., and Aspergillus sp. Key words: Jamur entomopatogen, Coptotermes sp.


Author(s):  
V. М. Lukomets ◽  
S. V. Zelentsov

To improve the effectiveness of the soybeans and oil flax breeding, research to improve existing and develop new breeding methods are conducting in all-Russia Research institute of Oil Crops (Krasnodar). One of the improved methods for the soybean breeding, based on the use of sources of complexes of compensatory genes, is the CCG technology, which allows to create varieties with an increased yield of a heterotic level transmitted along the progeny for the entire life cycle of the variety. For the purpose of non-transgenic production of new traits, a theory of polyploid recombination of the genome (TPR) was formulated, which models the mechanism of the natural formation of polymorphism in the centers of origin of cultivated plants. On the basis of this theory, a method of breeding (TPR-technology) has been developed, which makes it possible to obtain recombinant reploids of soybeans and oil flax with an extended spectrum of traits. Of these reploids, the soybean lines with increased sucking force of the roots, providing high drought resistance, were distinguished; cold-resistant soybean lines, which stand in the phase of shoots of freezing to minus 5 °С; lines of oil flax with complete resistance to flax sickness of soil and high resistance to Fusarium; winter-hardy flax lines that withstand winter frosts down to minus 20–23 °С and ripen one and a half months earlier than spring sowings. Another original developed method is the ODCS-technology for isolating and selecting soybean genotypes with high resistance to fungal pathogens. The physiological basis of ODCS-technology is the blocking of osmotic nutrition of pathogenic fungi due to genetically determined increased osmotic pressure in the tissues of host plants. The practical implementation of CCG-, TPR- and ODKS-technologies in the selection process, allowed to create a whole series of soybean and oil flax varieties with improved or new traits.


1999 ◽  
Vol 380 (7-8) ◽  
pp. 855-864 ◽  
Author(s):  
F. J. Maier ◽  
W. Schäfer

Abstract Random insertional mutagenesis is a powerful tool to investigate the molecular basis of most genetically determined processes, for example in pathogenic fungi. An improved version of this method is the insertional mutagenesis via restriction enzyme mediated integration (REMI). Transformation efficiency and mode of vector integration are species dependent and further influenced by vector conformation, restriction enzyme activity, and transformation protocol. An overview is given, covering the mutants and already identified genes obtained after REMI mutagenesis. An outlook describes the future developments in the field.


2019 ◽  
Vol 9 (1) ◽  
pp. 160
Author(s):  
Nahla Tharwat Elazab

In recent year&rsquo;s endophytic fungi has become a major concern on their host plants by enhancing their growth, increasing their fitness, strengthening their tolerances to abiotic and biotic stresses, and promoting their accumulation of secondary metabolites. Kingdom of Saudi Arabia has a wide range of flora which may be a rich source of endophytic fungi so that, the present study involves diversity and bioactivity of the endophytic fungal community in Al-Qassim region from 15 wild plants 162 isolates were obtained and identified. Among them, the most common isolates were Aspergillus niger, Aspergillus terreus, Aspergillus ochraceous and Trichoderma viride, these four endophytic isolates were examined for its antagonistic effect against six phytopathogenic fungi using two different assays, Dual-culture and Culture filtrate. Trichoderma viride recorded the most significant growth inhibition of almost pathogenic fungi followed by the three endophytic Aspergillus spp. In addition, these four endophytic fungi were screened for the production of some extracellular enzymes such as protease, cellulose, amylase, pectinase and xylanase. Our results show the ability of these isolates to produce these extracellular enzymes so this indicated the possible role of endophytic fungi as a biocontrol agent of plant disease.


2013 ◽  
Vol 54 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Alicja Saniewska

The inhibitory effect of crab-shell chitosan, medium (200-800 cps) and high molecular weight ( 800-2000 cps) (purchased from Sigma-Aldrich Chemicals) toward <i>Alternaria alternata, Botrytis tulipae, Fiisarium oxysporum</i> f. sp. <i>callistephi, Fusarium oxysporum</i> f. sp. <i>tulipae, Phoma narcissi</i> and <i> Phoma poolensis</i> was evaluated <i>in vitro</i> and in <i>vivo</i>. The chitosan evidently inhibited in vitro growth of all tested pathogens, with a marked effect at higher concentrations above 200 μg/cm<sup>3</sup>. Chitosan at a concentration of 1,25; 2,5 and 5,0 mg/cm<sup>3</sup> didn't have inhibitory action in appearance of fungi growth on naturally contaminated <i>Callistephus chinensis</i> seeds. At the same concentrations, chitosan applied as bulb scales dressing of <i>Hymenocallis narcissiflora</i> bulbs, before inoculation or after inoculation with <i>Phoma narcissi</i>, inhibited the development of necrotic spots on scales. Chitosan used preventively or curatively at a concentrations of 1,25; 2,5 and 5,0 mg/cm<sup>3</sup> indicated inhibitory effect on development of <i>Fusarium oxysporum</i> f. sp. <i>tulipae</i> on tulip bulbs. Chitosan at a concentration of 10 mg/cm<sup>3</sup> applied preventively (first spray 12th June) was very effective in the control of <i>Puccinia antirrhini</i> on snapdragon in the field. The strongest inhibitory effect was observed on snapdragon treated 8 times at week intervals.


2018 ◽  
Vol 6 (2) ◽  
pp. 59-66
Author(s):  
Raihan I Raju

A number of seed borne fungi such as- Fusarium moniliforme, Curvularia lunata, Alternaria solani, Helminthosporium solani, Aspergillus flavus, A. niger and Penicillium spp. were identified from the selected BARI-8, Nilima, Patharkuchi, Roma and Ratan varieties of tomato seeds. The highest (2.53%) mean incidence of the fungi F. moniliforme were recorded in tomato variety Roma, BARI-8, Nilima and Ratan while the lowest (0.13%) mean incidence of the fungi Penicillium was found in Ratan. The maximum percent of germination (64%) was recorded in both BARI-8 and Patharkuchi varieties, while the minimum (7%) germination in Nilima. The highest seedling vigor index (632.96) was encountered in BARI-8 and the lowest in Nilima. Trichoderma viride, T. harzianum and T. koningii were used as bio-control agents against major seed borne fungi. T. viride showed the significantly effective mycelial growth inhibition against F. moniliforme and C. lunata, while T. harzianum and T. koningii showed poor performance against both tested fungi. In case of botanical extracts, Lawsonia inermis exhibited the maximum (82.15% and 86.24%) inhibition of mycelium growth of F. moniliforme and C. lunata, respectively. Chemical fungicides, Bavistin (0.5 gm/l) inhibited 65% mycelial growth against F. moniliforme, while higher concentration of chemical fungicide gave 81% inhibition of C. lunata. The results suggested that, L. inermis phytoextract can possibly be exploited for the management of seed-borne pathogenic fungi of tomato in an environmental friendly way.Jahangirnagar University J. Biol. Sci. 6(2): 59-66, 2017 (December)


2011 ◽  
Vol 3 (4) ◽  
pp. 79-87 ◽  
Author(s):  
Mohamed Yosseif MOUBARK ◽  
Montaser Fawzy ABDEL-MONAIM

This study evaluated the effectiveness of applying the bioagents Bacillus subtilis (isolate BSM1), B. megaterium (isolate BMM5), Trichoderma viride (isolate TVM2) and T. harzianum (isolate THM4) for the control of rot root disease caused by Fusarium graminearum, Drechslera halodes and Rhizoctonia solani on two wheat cultivars ('Sakha 93' and 'Bani Suif 5') under greenhouse conditions. Moreover, their effect wheat growth and yield were also studied under field conditions. In vitro, all tested bioagents were significantly in the reduced redial growth of the pathogenic fungi. Trichoderma viride was active more than the other tested bioagents followed by T. harzianum, while B. subtilis was the least ones. Under greenhouse conditions, all tested bioagents were able to reduce significantly damping-off and root rot caused by the tested pathogens compared with control and increased fresh and dry weight of the survival plants when applied as soil or grain treatments however, there was variation among bioagent isolates effect on reduction of disease severity both application methods. Trichoderma viride and B. megaterium were recorded the highest effective in this respect compared with other tested bioagents. Under field conditions, analysis of variance and mean performance were estimated for four characters: grain yield 4.8 m-2, No. of spikes m-2, No. of kernels spike-1 and 1,000-kernel weight. Significant mean squares were obtained for all studied characters between the seasons (S), methods (M), (S) (M), treatments (T), (S) (T), (M) (T) and (S) (M) (T) for 'Sakha 93' cultivar and 'Bani Suif 5' cultivar except application methods and (S) (M) for number of kernels spike-1 and 1,000-kernel weight, respectively. While the treatments T. harzianum and B. megaterium were the best treatments to increase grain yield, the treatments B. subtilis and T. harzianum were best treatments to increase number of spikes and the treatments B. subtilis and B. megaterium were best treatments to increase number of kernels for soil and grain application methods, respectively.


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