Biology of Colletotrichum gloeosporioides Isolates From Tropical Pasture Legumes.

1986 ◽  
Vol 34 (5) ◽  
pp. 537 ◽  
Author(s):  
HJ Ogle ◽  
JAG Irwin ◽  
DF Cameron
Keyword(s):  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Leaf Blight ◽  
The Other ◽  
Tropical Pasture ◽  
Optimum Temperature ◽  
Stylosanthes Guianensis ◽  
Size And Shape ◽  
Pasture Legumes

The relationships between isolates of Colletotrichum gloeosporioides from Stylosanthes guianensis (an anamorphic and a teleomorphic isolate), Aeschynomene falcata and Centrosema pubescens were investi- gated by comparing their morphology, temperature relations, symptomatology and pathogenicity. The Stylosanthes and Aeschynomene isolates caused more severe symptoms on the host from which they were isolated than on the other hosts. The Centrosema isolate caused moderate infection on Stylosanthes and mild infection on Centrosema. The anamorphic isolate from Stylosanthes produced leaf blight while the other isolates produced localised necrotic lesions. Conidia of the Centrosema isolate and the teleomorphic isolate from Stylosanthes were relatively uniform in size and shape and rounded at both ends. Both isolates produced fertile perithecia. Conidia of the Aeschynomene isolate and the anamorphic Stylosanthes isolate were more variable in shape and usually tapered at one end. The optimum temperature for mycelial growth of the anamorphic Stylosanthes isolate and the Aeschynomene isolate was 25°C, and for growth of the teleomorphic Stylosanthes isolate and the Centrosema isolate 27-29°C. Infection by the anamorphic and the teleomorphic Stylosanthes isolates proceeded in a similar fashion. Germinated spores and unmelanised appressoria were first observed at 6 h, melanised appressoria at 12 h and multiple appressoria and penetration at 24 h after inoculation. The anamorphic isolate produced significantly more successful penetrations than the teleomorphic isolate.

Seasonal changes in growth and nodulation of perennial tropical pasture legumes in the field. II. Effects of controlled defoliation levels on nodulation of Desmodium uncinatum and Phaseolus atropurpureus

1970 ◽  
Vol 21 (2) ◽  
pp. 207 ◽  
Author(s):  
PC Whiteman
Keyword(s):  
Field Experiment ◽  
Seasonal Changes ◽  
Plant Age ◽  
The Other ◽  
Tropical Pasture ◽  
Nodule Number ◽  
Pasture Legumes ◽  
Tropical Legumes ◽  
Young Leaves ◽  
Nodule Population

In a field experiment comparing the effects of varying levels of defoliation on the nodulation of two tropical legumes, D. intortum cv. Greenleaf and P. atropurpureus cv. Siratro, five treatments were imposed: (1) control, (2) cutting at 3 in., (3) removal of all leaves and petioles, (4) removal of half the leaves, taking the young leaves, (5) removal of half the leaves, taking the old leaves. The defoliation treatments were imposed twice, at plant age 73 and 103 days, and sampled twice, at 18 and 26 days, after each defoliation. The effects of defoliation were not evident for at least 18 days, but subsequently the nodule weight per plant was reduced by defoliation, the reduction being related to the severity of the initial defoliation. Cutting reduced both the nodule number and weight per nodule in both species. In P. atropurpureus removing all leaves had a similar effect to cutting. In the other defoliation treatments in both species, the weight per nodule declined even though the nodule number increased, and thus the nodule weight per plant increased or remained constant. This provided evidence that changes in nodule weight induced by defoliation were related to a loss of part of the original nodule population and initiation of new nodules.

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.

Peanut Web Blotch: I. Cultural Characteristics and Identity of Causal Fungus1

1984 ◽  
Vol 11 (2) ◽  
pp. 109-114 ◽  
Author(s):  
R. A. Taber ◽  
R. E. Pettit ◽  
G. L. Philley
Keyword(s):  
South Africa ◽  
Cultural Studies ◽  
Mycelial Growth ◽  
Fungal Species ◽  
Optimum Temperature ◽  
Cultural Characteristics ◽  
Foliar Disease ◽  
The Usa

Abstract A foliar disease of peanuts, previously unreported in the USA, was found in Texas in 1972. The pathogen was identified as a species of Ascochyta. Further cultural studies have revealed this fungus to be Phoma arachidicola Marasas, Pauer, and Boerema. Pycnidia form profusely at 20 C and 25 C. Pycnidiospores are borne on short pycnidiosphores and are predominantly one-celled in culture. Spores produced in pycnidia on infected leaflets become 1 septate. Large 1-septate spores, as well as an occasional 2-septate spore, may form in culture. Optimum temperature for mycelial growth in 20 C; little or no growth occurs at 5 C or above 30 C. The teleomorphic state develops in the field on fallen leaflets and can be induced to form in the laboratory on sterilized peanut leaflets between 15 and 20 C. Cultures derived from single ascospores form pseudothecia. Pycnidiospores, ascospores, and chlamydospores are all infective units. Because this fungus produces hyaline ascospores and pseudoparaphyses, it has been transferred to the genus Didymella as Didymella arachidicola (Choch.) comb. nov. Comparisons with 15 isolates causing web blotch of peanut in the USA, Argentina, and South Africa indicate that web blotch symptoms are produced by the same fungal species.

The ability of ectomycorrhizal fungi to utilize fatty acids and a lipid as a carbon source for mycelial growth

2003 ◽  
Vol 81 (12) ◽  
pp. 1285-1292 ◽  
Author(s):  
Takefumi Hattori ◽  
Akira Ohta ◽  
Masayuki Itaya ◽  
Mikio Shimada
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Carbon Source ◽  
Ectomycorrhizal Fungi ◽  
Mycelial Growth ◽  
The Other ◽  
Other Hand ◽  
The Family ◽  
Ecm Fungi ◽  
Relative Utilization

We have investigated growth of ectomycorrhizal (ECM) fungi (i.e., 55 strains of 32 species in 15 genera) on saturated (palmitate), monounsaturated (oleate), diunsaturated (linoleate), triunsaturated (linolenate) fatty acids, and the triacylglyceride of oleate (triolein) lipid to elucidate an ability to utilize the fatty acids and lipid as a carbon source for growth. Relative utilization ratios (URs, %) based on mycelial growth on glucose suggest that ECM fungi belonging to the family Thelephoraceae have an ability to utilize palmitate. On the other hand, ECM fungi in the genus Laccaria can utilize at least either palmitate or oleate. Furthermore, Hygropharus russula grows on palmitate, oleate, and slightly on triolein. Lactarius chrysorrheus grows only on palmitate. These fatty-acid- and lipid-utilizing fungi may be promising as model fungi for further elucidation of the metabolic ability to utilize the fatty acids and lipid as a carbon source. On the contrary, the fungi in the genus Suillus were shown to scarcely utilize the fatty acids and lipid. Furthermore, most ECM fungi did not grow on either linoleate or linolenate.Key words: carbon source, ectomycorrhizal fungi, fatty acid, lipid, mycelial growth.

scholarly journals Observations on the Fat Globules in Milk

1913 ◽  
Vol 5 (3) ◽  
pp. 331-356 ◽  
Author(s):  
W. F Cooper ◽  
W. H Nuttall ◽  
G. A Freak
Keyword(s):  
Annual Report ◽  
The Other ◽  
Optimum Temperature ◽  
Fat Globules ◽  
Chief Factors ◽  
Mean Size ◽  
The Subject ◽  
The Mean ◽  
Definite Result

Results of our previous work were published in the Journ. of Agric. Sri., IV, 1911. There, also, a brief summary of the chief papers published on the subject of the fat globules was given, to which it is unnecessary to refer in detail here.When the work was first commenced in 1909, the problem before us was the consideration of the variation in the size of the fat globules, with relation to churning, as regards the different breeds of cattle. The breed was considered because it was usually supposed that this was one of the chief factors which influenced churning. The most definite result of our work was that it was shown that consideration must be given to the character of the milk, irrespective of the breed. This conclusion is quite contrary to that of other workers, but an examination of their figures shows, undoubtedly, that this is actually the case: the results given by Woll (Digestion Expts., Seventh Annual Report, Agric. Expt. Stat, Wisconsin, 1890, 238; also Agric. Sci., 1892, vi, 445) emphasise this point particularly. It is also shown by this year's work, as may be seen from Tables V–XI.The comparative size of the globules has been worked out very thoroughly by Gutzeit, who measured the mean volume of the globule. Other workers give their results as “relative sizes.” In our work we attempted to ascertain the distribution of the fat in the globules, and to this end the number of globules of each size was determined, and curves were drawn. The result of this, however, was negative. At that time we were considering the breeds of the cows from which the milks were obtained; had we considered them solely as milks of a certain mean size of globule, much more might have been achieved.An apparatus was devised to give an absolute figure for the churnability of any cream, but, until the effect of the other factors has been determined, it is impossible to interpret the results. Some experiments to ascertain the optimum temperature were described also.

Taxonomic review of Epicadinus Simon, 1895 (Araneae: Thomisidae) 

Zootaxa ◽  
2018 ◽  
Vol 4459 (2) ◽  
pp. 201 ◽  
Author(s):  
ANDRÉ WANDERLEY DO PRADO ◽  
RENNER LUIZ CERQUEIRA BAPTISTA ◽  
MIGUEL MACHADO
Keyword(s):  
French Guiana ◽  
The Other ◽  
Valid Species ◽  
Variable Size ◽  
Size And Shape ◽  
Taxonomic Review ◽  
Nomen Dubium ◽  
The World ◽  
Senior Synonym

The genus Epicadinus Simon, 1895 can easily be distinguished from the other Neotropical Stephanopines by their abundant and robust setiferous tubercles, topped by elongated macrosetae, which cover most of the tegument. Additionally, the genus can be recognized by a pair of conical ocular mounds above the ALE, the anterior eye row very recurved, posterior one slightly procurved; carapace flattened and without tubercles, and opisthosoma with three conical projections (“tubercles”) of variable size and shape. This work is a taxonomic review of the 12 valid species of Epicadinus as listed in version 19 of the World Spider Catalogue (2018), whose hitherto known distribution included few records from Brazil, French Guiana, Bolivia and Peru, and only one from Mexico. Four valid species are recognized: Epicadinus biocellatus Mello-Leitão, 1929; E. trispinosus (Taczanowski, 1872) [with two junior synonyms E. trifidus (Pickard-Cambridge, 1893) syn. nov. and E. cornutus (Taczanowski, 1872) syn. nov.]; E. spinipes (Blackwall, 1862) [with two junior synonyms E. albimaculatus Mello-Leitão, 1929 syn. nov. and E. gavensis Soares, 1946 syn. nov]; and E. villosus [with two junior synonyms E. helenae Piza, 1936 syn. nov. and E. marmoratus Mello-Leitão, 1947 syn. nov.]. Epicadinus polyophthalmus Mello-Leitão, 1929 and Epicadinus tuberculatus Petrunkevitch, 1910 are transferred to Epicadus. Epicadus polyophthalmus (Mello-Leitão, 1929) comb. nov. is considered a nomen dubium. Epicadus tuberculatus (Petrunkevitch, 1910) comb. nov. is a senior synonym of Epicadus pustulosus (Mello-Leitão, 1929) syn. nov. 

scholarly journals Compatibility of fungal bioagent for bacterial leaf blight of rice with chemical pesticides, commonly used in rice cultivation

2013 ◽  
Vol 5 (2) ◽  
pp. 378-381 ◽  
Author(s):  
Gokil Prasad Gangwar
Keyword(s):  
Adverse Effect ◽  
Biological Control ◽  
Chemical Control ◽  
Mycelial Growth ◽  
Crop Protection ◽  
Leaf Blight ◽  
Rice Cultivation ◽  
Bacterial Leaf Blight ◽  
Copper Oxychloride ◽  
Chemical Pesticides

Though the pesticides have adverse effects but they still are very important in crop protection. Hence, present study on compatibility of fungal bioagent (Trichoderma harzianum) of bacterial leaf blight of rice with chemical pesticides which are commonly used in rice cultivation was carried out with aim to look the possibilities of integrating biological control with chemical control to manage bacterial leaf blight of rice effectively. All the chemical pesticides (fungicides, antibiotic, insecticides and herbicides) exhibited varying adverse effect on mycelial growth of T. harzianum but none of these was antisporulant. Among fungicides and antibiotic, copper oxychloride and streptocycline was compatible with T. harzianum at all concentrations (2000, 1000, 500 and 250 ppm) but mancozeb exhibited compatibility only on lower concentrations (500 and 250 ppm). All insecticides and herbicides were compatible with T. harzianum at all concentrations (2000, 1000, 500 and 250 ppm). Further studies are required in this area of research.

Sign in / Sign up

Export Citation Format

Share Document