scholarly journals Absence of Corn Stunt Spiroplasma and Maize Bushy Stunt Phytoplasma in Leafhoppers (Hemiptera: Cicadellidae) that Inhabit Edge Grasses Throughout Winter in Jalisco, Mexico

2015 ◽  
Vol 98 (3) ◽  
pp. 967-969 ◽  
Author(s):  
Rosaura Torres-Moreno ◽  
Gustavo Moya-Raygoza ◽  
Edel Pérez-López
Keyword(s):  
Corn Stunt ◽  
Corn Stunt Spiroplasma ◽  
Maize Bushy Stunt Phytoplasma

scholarly journals Aspectos da biologia da cigarrinha-do-milho, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae)

1999 ◽  
Vol 28 (3) ◽  
pp. 413-420 ◽  
Author(s):  
José M. Waquil ◽  
Paulo A. Viana ◽  
Ivan Cruz ◽  
Jamilton P. Santos
Keyword(s):  
Dalbulus Maidis ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma ◽  
Maize Bushy Stunt Phytoplasma ◽  
Maize Rayado Fino Virus

Na cultura do milho, a cigarrinha, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae) é vetora de três patógenos: Spiroplasma kunkelii (corn stunt spiroplasma), o fitoplasma do milho (maize bushy stunt phytoplasma) e o vírus da risca do milho (maize rayado fino vírus). Os prejuízos causados por essas doenças podem variar de nove a 90 %, dependendo da susceptibilidade das cultivares e dos patógenos envolvidos. O objetivo deste trabalho foi estudar aspectos da biologia de D. maidis, sob condições controladas e utilizando-se insetos e cultivares de milho e sorgo adaptados às condições brasileiras. Plântulas de milho e de sorgo foram cultivadas em vasos plásticos, cobertas com gaiolas de plástico e infestadas com 10 adultos por planta. Sempre utilizando-se 10 plântulas por tratamento, foram conduzidos dois ensaios independentes. No 1°, estudou-se o período de incubação nas temperaturas constantes de 17, 20, 23, 26, 29 e 32ºC ± 1ºC e fotofase de 12 h. No 2°, estudou-se o desenvolvimento de ninfas à temperatura constante de 26,5 ± 2ºC e mesma fotofase. O período de incubação foi mais curto nas temperaturas de 26 e 29ºC, nas quais cerca de 70% das ninfas levaram nove dias para a eclosão. Foram observados até cinco ínstares, embora cerca de 76% da população tenha completado o desenvolvimento passando por apenas quatro ínstares. A duração média de cada instar foi de 3,14 dias. Os adultos viveram em média 51,4 dias e o ciclo médio de ovo a adulto foi de 26,3 dias. Portanto, para a manutenção de colônias de insetos ou no desenvolvimento de estudos com essa espécie é importante observar os limites máximos e mínimos de temperatura.

An in vitro comparison of some biochemical and biological properties of California and Morocco isolates of Spiroplasma citri

1979 ◽  
Vol 25 (10) ◽  
pp. 1125-1132 ◽  
Author(s):  
E. C. K. Igwegbe ◽  
Clauzell Stevens ◽  
John J. Hollis Jr.
Keyword(s):  
Biological Properties ◽  
Tetrazolium Chloride ◽  
Potassium Tellurite ◽  
Spiroplasma Citri ◽  
Antimicrobial Substances ◽  
Solid Media ◽  
Corn Stunt ◽  
Optimum Ph ◽  
Corn Stunt Spiroplasma

California (CI) and Morocco (MI) isolates of Spiroplasma citri incubated at 4, 24, or 32 °C yielded typical mycoplasma colonies on agar at each passage. MI but not CI incubated at 37 °C yielded a few colonies at first passage only, but both isolates did not survive 42 °C for 3 days. In liquid and solid media, best growth of both isolates occurred between pH 7.0 and pH 8.5 and the optimum pH for growth in liquid medium was 7.5 (CI) and 8.5 (MI). The sensitivity of CI or MI to 21 antimicrobial substances was identical in most cases. Corn stunt spiroplasma (CSS) and CI had similar antimicrobial substance spectrum, although CSS was much more sensitive to any given substance than CI. CI fermented the following with acid production: cellobiose, dextrose, galactose, trehalose, fructose, mannitol. maltose, and sucrose. MI fermented all these in addition to arabinose, mannose. sorbitol, and raffinnose. Arginine but not urea was hydrolyzed by both isolates. CI or MI failed to reduce potassium tellurite, methylene blue, or tetrazolium chloride.

Presence of spiroplasma-inhibitory substances in plant tissue extracts

1980 ◽  
Vol 26 (7) ◽  
pp. 807-811 ◽  
Author(s):  
C. H. Liao ◽  
T. A. Chen
Keyword(s):  
Plant Extracts ◽  
Plant Tissue ◽  
Cytoplasmic Membrane ◽  
Cynodon Dactylon ◽  
Culture Media ◽  
Cell Replication ◽  
Spiroplasma Citri ◽  
Tissue Extracts ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma

Plant tissue extracts prepared from corn, periwinkle, celery, and lettuce contain substance(s) which are inhibitory for spiroplasma growth in culture media. The inhibition titer, measured as the highest dilution of plant extracts which block spiroplasma growth, is inversely proportional to the spiroplasma concentration used for testing. At a concentration of 104 cells/mL, the growth of four spiroplasma isolates investigated (corn stunt spiroplasma, Spiroplasma citri, honey bee spiroplasma, and Bermuda grass (Cynodon dactylon) spiroplasma) was suppressed by the addition of corn and periwinkle extracts up to dilutions of 1/160 and 1/1280, respectively. Spiroplasmas remained viable in extract-supplemented media for at least 5 days and continued to multiply shortly after the plant extract was removed. These results suggest that (1) the inhibitory action of plant extracts is spiroplasmastatic, and (2) inhibitory factors may temporarily bind to cytoplasmic membrane and subsequently suppress the process of cell replication. The anti-mycoplasma activity was greatly reduced when the extract was placed in boiling water for 10 min or at 37 °C for 5 days. No loss of activity was detected when the extract was kept at −20 or 4 °C for 5 days.

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