scholarly journals Isolasi, identifikasi dan karakterisasi penyebab penyakit bercak daun pada semai pinus di perum perhutani BKPH Purworejo, KPH Kedu Selatan

2020 ◽  
Vol 14 (1) ◽  
pp. 21-32
Author(s):  
Nur Hidayati ◽  
Siti Husna Nurrohmah ◽  
Fithry Ardhany ◽  

Pinus merkusii, a multiuse tree, is cultivated at Indonesian Plantation. Pinus plantation have been threatened by rust/spot leaf disease. The pathogen has infected pinus seedlings at Perum Perhutani, BKPH Purworejo, KPH Kedu Selatan and cause high mortality. The aims of this research to identify pathogen causing rust/spot leaf thus information how to control can be observed. Pathogens were isolated from infected leaves, and grown on the potato dextrose agar (PDA) and observed macroscopis and microscopis and identified. The pathogens also were inoculated to healthy seedlings (Postulat Koch Test). The result shows that pathogen causing rust/spot leaf on seedlings pine is Pestalotia sp with characteristic white colony, hypha has aservuli with conidia that have 25 septums and at the edge, some structure looks like feather whipped 3-5. Potulat Koch test indicated that inoculated healthy seedling shows similar symptom with infected seedlings. Rust/spot leaf has similar sympto and sign. Spot or rust appear on leaves started from edge and spread to base. At first, spots were formed in small size and separate each other but they developed and became larger and wider and fused.

2021 ◽  
Vol 11 (2) ◽  
pp. 65-71
Author(s):  
Masendra Masendra ◽  
Brandon Arsito Verick Purba ◽  
Ganis Lukmandaru

The outer part of a tree, known as the bark, protects the internal tissues from external conditions and attacks from microorganisms. Its antifungal activities are due to the presence of chemicals in this bark. This study aimed at evaluating the toxicity of triterpenoids and steroids from the bark of Pinus merkusii against Phanerochaete chrysosporium (white-rot). The triterpenoids and steroids were isolated from n-hexane extract of the bark through column chromatography. Then, the antifungal activity was evaluated by measuring the growth rate of the fungus on potato dextrose agar (PDA) medium in a Petri dish. The isolation resulted in three triterpenoids (3β- methoxyserratt-14-en-21-one, serrate-14-en-3β,21β –diol, 3α,21β- dimethoxy-D14-serratene) and two steroids (β-sitosterol, Stigmast-4-en-3-one). There was more of antifungal activity with β-sitosterol and serrate-14-en-3β,21β –diol, due to presence of hydroxyl bond and their hydrophobicity.


2020 ◽  
Vol 142 ◽  
pp. 47-53
Author(s):  
K Béland ◽  
G Séguin ◽  
S Lair

An unusually high mortality rate due to verminous (Philometra rubra) coelomitis was documented in wild-hatched striped bass Morone saxatilis raised in a fish hatchery as part of a stock restoration program. To decrease the parasitic burden and therefore potentially minimize mortality, the effectiveness of 2 different anthelmintics was evaluated. Two trials were conducted on wild-collected fingerlings naturally infected by P. rubra. In 2006, 144 yearling fish were randomly assigned to 4 experimental groups: (1) levamisole (Levasol®) at 2 mg l-1 via immersion for 8 h once weekly for 3 wk; (2) levamisole at a dose of 2.5 mg kg-1 biomass via feed once daily for 7 d; (3) emamectin benzoate (Slice®) at a dose of 0.05 mg kg-1 biomass via feed once daily for 7 d; and (4) control. Emamectin successfully eliminated live nematodes in 84.9% of the fish, whereas the administration of levamisole, either via immersion or feed, was not successful in significantly reducing the number of live P. rubra. In 2007, the administration of the same dosage of emamectin to approximately 1000 naturally infected yearling striped bass was associated with a 100% mortality rate of P. rubra in the 30 fish randomly examined 5 wk after the beginning of the treatment. Results of these trials indicate that, at the dosage used, the administration of emamectin at the end of the summer is safe for striped bass yearlings and considerably reduces the prevalence and intensity of the infection by this parasite.


1961 ◽  
Vol 37 (3) ◽  
pp. 441-444
Author(s):  
A. Nygaard ◽  
M. Felbo ◽  
J. Pedersen

ABSTRACT In a study of 173 pregnancies in 130 diabetic mothers of White's groups B, C and D who had received long-term treatment during pregnancy, the authors found cases of diabetes – in addition to the mother – in the maternal family, in the father and his family, or in the maternal as well as paternal family in a total of 100 pregnancies (57 %). The perinatal mortality was only slightly – and not significantly – higher among infants whose families included other diabetics than the mother. This higher mortality was found only among male infants of whom there was a preponderance in pregnancies with familial diabetes, but this was also not statistically significant. Thus, the result indirectly indicates that the primary cause of the high mortality among the infants of diabetic women must be the fact that the foetus develops in a diabetic environment.


Author(s):  
A. Muntala ◽  
P. M. Norshie ◽  
K. G. Santo ◽  
C. K. S. Saba

A survey was conducted in twenty-five cashew (Anacardium occidentale) orchards in five communities in the Dormaa-Central Municipality of Bono Region of Ghana to assess the incidence and severity of anthracnose, gummosis and die-back diseases on cashew. Cashew diseased samples of leaves, stem, inflorescences, twigs, flowers, nuts and apples showing symptoms (e. g. small, water-soaked, circular or irregular yellow, dark or brown spots or lesions on leaves, fruits and flowers, sunken surface, especially on the apples, blight, gum exudates) were collected for isolation of presumptive causative organism. The pathogen was isolated after disinfecting the excised diseased pieces in 70% ethanol, plated on potato dextrose agar (PDA) and incubated at 28 oC for 3 to 7 days. The identity of the putative pathogen was morphologically and culturally confirmed as belonging to Colletotrichum gloeosporioides species complex using standard mycological identification protocols. The pathogen had varied conidia sizes of between 9-15 up to 20 μm in length and diameter of 3-6 μm. The conidia were straight and cylindrically shaped with rounded or obtuse ends. The septate mycelium was whitish-grey, velvety and cotton-like in appearance from the top. The results confirmed the presence of the pathogen in the orchards with incidence ranging from 6.9% and 14.0% for gummosis and averaged 22.9% for anthracnose infected orchards. The result of the pathogenicity test confirmed the isolates to be pathogenic on inoculated cashew seedlings and were consistently re-isolated, thereby establishing the pathogen as the true causal agent of the said diseases in cashew trees and thus completed the Koch’s postulate.


2019 ◽  
Vol 7 (4) ◽  
pp. 1036-1040
Author(s):  
Sadhvik Reddy ◽  
Saumit Sandesh C ◽  
Srividya KA ◽  
Sandeep Reddy ◽  
Mohana Kumar S ◽  
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2018 ◽  
Vol 6 (6) ◽  
pp. 1493-1499
Author(s):  
Shrutika.C.Rampure . ◽  
Dr. Vindhya .P. Malagi ◽  
Dr. Ramesh Babu D.R

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