The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform

Philippe Rott - One of the best experts on this subject based on the ideXlab platform.

  • Spread of Sugarcane yellow leaf virus in initially Disease-Free sugarcane is linked to rainfall and host resistance in the humid tropical environment of Guadeloupe
    European Journal of Plant Pathology, 2011
    Co-Authors: Jean Heinrich Daugrois, Carine Edon-jock, Sandrine Bonoto, Jean Vaillant, Philippe Rott
    Abstract:

    Sugarcane yellow leaf virus , the causal agent of yellow leaf, is transmitted from plant to plant by aphids. Understanding and evaluating the epidemic risks due to spread of yellow leaf by aphids is an important feature for sugarcane production. Four distinct sugarcane trials were set up with Disease-Free Plants to study the relationship between spread of yellow leaf, the vector dynamics and environmental conditions that may favour yellow leaf epidemics. The study was performed by surveys of vector populations and determination of plant infections. Sugarcane cultivar SP71-6163, highly susceptible to yellow leaf, was analyzed spatially at different dates in all four trials and compared to commercial cultivars in two of the four trials. These surveys allowed us to identify a correlation between the aphid dynamics in the field and yellow leaf progress. Additionally, a negative correlation was found between rainfall during the first weeks after transferring sugarcane Plants to the field and aphid dispersal within the field. This later result revealed an impact of rainfall on aphid invasion and subsequent plant infection by SCYLV. If aphids are the key factor for disease spread, plant response varied also according to cultivar resistance with high variation depending on rain conditions.

  • Spread of Sugarcane yellow leaf virus in initially Disease-Free sugarcane plots is linked to rainfall and host resistance in the humid tropical environment of Guadeloupe
    European Journal of Plant Pathology, 2011
    Co-Authors: Jean Heinrich Daugrois, Carine Edon-jock, Jean Vaillant, Sandrine Bonotto, Philippe Rott
    Abstract:

    Sugarcane yellow leaf virus, the causal agent of yellow leaf, is transmitted from plant to plant by aphids. Understanding and evaluating the epidemic risks due to spread of yellow leaf by aphids is an important feature for sugarcane production. Four distinct sugarcane trials were set up with Disease-Free Plants to study the relationship between spread of yellow leaf, the vector dynamics and environmental conditions that may favour yellow leaf epidemics. The study was performed by surveys of vector populations and determination of plant infections. Sugarcane cultivar SP71-6163, highly susceptible to yellow leaf, was analyzed spatially at different dates in all four trials and compared to commercial cultivars in two of the four trials. These surveys allowed us to identify a correlation between the aphid dynamics in the field and yellow leaf progress. Additionally, a negative correlation was found between rainfall during the first weeks after transferring sugarcane Plants to the field and aphid dispersal within the field. This later result revealed an impact of rainfall on aphid invasion and subsequent plant infection by SCYLV. If aphids are the key factor for disease spread, plant response varied also according to cultivar resistance with high variation depending on rain conditions.

  • Infection of sugarcane by SCYLV associated with high populations of Melanaphis sacchari in Guadeloupe
    2003
    Co-Authors: Jean Heinrich Daugrois, Sandrine Bonotto, Myriam Siegwart, Steeve Joseph, Philippe Rott
    Abstract:

    A sugarcane trial (18 rows of 65m each) was established with 1,900 disease free tissue culture propagated Plants of cultivar SP71-6163. In Brazil, this cultivar is highly susceptible to yellow leaf caused by the Sugarcane yellow leaf virus (SCYLV). Two rows of SCYLV-infected Plants of cultivar FR90714 were also planted next to one side of the SP71-6163 plot. Colonization of Disease-Free Plants by aphids was monitored for 22 weeks after sugarcane planting in the field. The number of SCYLV-infected Plants was estimated by tissue blot immunoassay (TBIA) with the bottom part of the midrib of the top visible dewlap leaf Two aphid species, Melanaphis sacchari and Sipha flava, were identified in the trial. Only populations of M. sacchari, a vector of SCYLV, were, however, taken into account during the survey. M. sacchari was first observed on two Plants out of the 1,900 four weeks after sugarcane planting in the field. Aphid population increased slowly until 10 weeks when 301 (17%) Plants were colonized with a mean of 51 aphids per colonized plant. Then, the number of aphids in the field decreased, most likely due to natural control by ladybugs which were also present on the sugarcane leaves. Aphid population increased again between 17 and 22 weeks after planting and, on week 22, 2,822 M. sacchari aphids were found on 41 colonized Plants out of 47 (87%) randomly observed. One month earlier, only 222 Plants out of the 1,900 (12%) were colonized by M. sacchari. One top visible dewlap leaf was sampled every 10 Plants of SP71-6163 on each sugarcane row every 1-7 weeks (182 to 200 leaves per sampling date). The first SCYLV-infected leaves were found on two Plants, 16 weeks after planting. Four weeks later, when high aphid populations were observed, 8% of samples were positive. After 25 weeks, one leaf was sampled from each plant in the trial and 113 leaves out of 1879 (6%) were infected by SCYLV. Infected Plants were randomly distributed in the field, but the first row adjacent to infected Plants of cultivar FR90714 showed a higher percentage of infection (17%). Percentage of infected leaves remained at about 6% until the end of sampling, 38 weeks after planting. Sugarcane stalks were harvested after 44 weeks of growth in the field and, after five weeks of growth in the first ratoon crop, 170 out of 817 sampled leaves (21%) were infected by SCYLV. At the same time, aphids were observed on 112 out of 309 Plants (36%) and a mean population of 26 aphids per colonized plant was determined. Winged adult aphids were also observed on 28 Plants out of 309 (9%). In our trial, sugarcane infection by SCYLV seemed, therefore, to be associated with high aphid populations at the beginning of each crop. Rapid increase of yellow leaf incidence may therefore occur in Guadeloupe when diseased cane and aphid vectors of SCYLV are present. (Texte integral)

Paramvir Singh Ahuja - One of the best experts on this subject based on the ideXlab platform.

  • In vitro propagation of rose--a review.
    Biotechnology advances, 2005
    Co-Authors: Pratap Kumar Pati, Madhu Sharma, Siba Prasad Rath, Anil Sood, Paramvir Singh Ahuja
    Abstract:

    In vitro propagation of rose has played a very important role in rapid multiplication of cultivars with desirable traits and production of healthy and Disease-Free Plants. During the last several years, different approaches have been made for in vitro propagation of rose. Micropropagation using apical buds or nodal segments and understanding the specific requirements at different stages has been comprehensively covered in literature. New challenges for refinements of protocols for high rate of shoot multiplication and development of cost effective methods has gained importance in the recent past. Importance of liquid static culture for shoot proliferation and root induction for rose is also discussed in the present review. Further, the development of protocol for in vitro plant regeneration which is considered as most important step for successful implementation of various biotechnological techniques used for plant improvement programmes has been adequately addressed in literature. In rose, there are several reports which indicate rapid regeneration and multiplication through organogenesis or somatic embryogenesis. On the whole, the present review gives a consolidated account of in vitro propagation in rose.

Jean Heinrich Daugrois - One of the best experts on this subject based on the ideXlab platform.

  • Spread of Sugarcane yellow leaf virus in initially Disease-Free sugarcane is linked to rainfall and host resistance in the humid tropical environment of Guadeloupe
    European Journal of Plant Pathology, 2011
    Co-Authors: Jean Heinrich Daugrois, Carine Edon-jock, Sandrine Bonoto, Jean Vaillant, Philippe Rott
    Abstract:

    Sugarcane yellow leaf virus , the causal agent of yellow leaf, is transmitted from plant to plant by aphids. Understanding and evaluating the epidemic risks due to spread of yellow leaf by aphids is an important feature for sugarcane production. Four distinct sugarcane trials were set up with Disease-Free Plants to study the relationship between spread of yellow leaf, the vector dynamics and environmental conditions that may favour yellow leaf epidemics. The study was performed by surveys of vector populations and determination of plant infections. Sugarcane cultivar SP71-6163, highly susceptible to yellow leaf, was analyzed spatially at different dates in all four trials and compared to commercial cultivars in two of the four trials. These surveys allowed us to identify a correlation between the aphid dynamics in the field and yellow leaf progress. Additionally, a negative correlation was found between rainfall during the first weeks after transferring sugarcane Plants to the field and aphid dispersal within the field. This later result revealed an impact of rainfall on aphid invasion and subsequent plant infection by SCYLV. If aphids are the key factor for disease spread, plant response varied also according to cultivar resistance with high variation depending on rain conditions.

  • Spread of Sugarcane yellow leaf virus in initially Disease-Free sugarcane plots is linked to rainfall and host resistance in the humid tropical environment of Guadeloupe
    European Journal of Plant Pathology, 2011
    Co-Authors: Jean Heinrich Daugrois, Carine Edon-jock, Jean Vaillant, Sandrine Bonotto, Philippe Rott
    Abstract:

    Sugarcane yellow leaf virus, the causal agent of yellow leaf, is transmitted from plant to plant by aphids. Understanding and evaluating the epidemic risks due to spread of yellow leaf by aphids is an important feature for sugarcane production. Four distinct sugarcane trials were set up with Disease-Free Plants to study the relationship between spread of yellow leaf, the vector dynamics and environmental conditions that may favour yellow leaf epidemics. The study was performed by surveys of vector populations and determination of plant infections. Sugarcane cultivar SP71-6163, highly susceptible to yellow leaf, was analyzed spatially at different dates in all four trials and compared to commercial cultivars in two of the four trials. These surveys allowed us to identify a correlation between the aphid dynamics in the field and yellow leaf progress. Additionally, a negative correlation was found between rainfall during the first weeks after transferring sugarcane Plants to the field and aphid dispersal within the field. This later result revealed an impact of rainfall on aphid invasion and subsequent plant infection by SCYLV. If aphids are the key factor for disease spread, plant response varied also according to cultivar resistance with high variation depending on rain conditions.

  • Infection of sugarcane by SCYLV associated with high populations of Melanaphis sacchari in Guadeloupe
    2003
    Co-Authors: Jean Heinrich Daugrois, Sandrine Bonotto, Myriam Siegwart, Steeve Joseph, Philippe Rott
    Abstract:

    A sugarcane trial (18 rows of 65m each) was established with 1,900 disease free tissue culture propagated Plants of cultivar SP71-6163. In Brazil, this cultivar is highly susceptible to yellow leaf caused by the Sugarcane yellow leaf virus (SCYLV). Two rows of SCYLV-infected Plants of cultivar FR90714 were also planted next to one side of the SP71-6163 plot. Colonization of Disease-Free Plants by aphids was monitored for 22 weeks after sugarcane planting in the field. The number of SCYLV-infected Plants was estimated by tissue blot immunoassay (TBIA) with the bottom part of the midrib of the top visible dewlap leaf Two aphid species, Melanaphis sacchari and Sipha flava, were identified in the trial. Only populations of M. sacchari, a vector of SCYLV, were, however, taken into account during the survey. M. sacchari was first observed on two Plants out of the 1,900 four weeks after sugarcane planting in the field. Aphid population increased slowly until 10 weeks when 301 (17%) Plants were colonized with a mean of 51 aphids per colonized plant. Then, the number of aphids in the field decreased, most likely due to natural control by ladybugs which were also present on the sugarcane leaves. Aphid population increased again between 17 and 22 weeks after planting and, on week 22, 2,822 M. sacchari aphids were found on 41 colonized Plants out of 47 (87%) randomly observed. One month earlier, only 222 Plants out of the 1,900 (12%) were colonized by M. sacchari. One top visible dewlap leaf was sampled every 10 Plants of SP71-6163 on each sugarcane row every 1-7 weeks (182 to 200 leaves per sampling date). The first SCYLV-infected leaves were found on two Plants, 16 weeks after planting. Four weeks later, when high aphid populations were observed, 8% of samples were positive. After 25 weeks, one leaf was sampled from each plant in the trial and 113 leaves out of 1879 (6%) were infected by SCYLV. Infected Plants were randomly distributed in the field, but the first row adjacent to infected Plants of cultivar FR90714 showed a higher percentage of infection (17%). Percentage of infected leaves remained at about 6% until the end of sampling, 38 weeks after planting. Sugarcane stalks were harvested after 44 weeks of growth in the field and, after five weeks of growth in the first ratoon crop, 170 out of 817 sampled leaves (21%) were infected by SCYLV. At the same time, aphids were observed on 112 out of 309 Plants (36%) and a mean population of 26 aphids per colonized plant was determined. Winged adult aphids were also observed on 28 Plants out of 309 (9%). In our trial, sugarcane infection by SCYLV seemed, therefore, to be associated with high aphid populations at the beginning of each crop. Rapid increase of yellow leaf incidence may therefore occur in Guadeloupe when diseased cane and aphid vectors of SCYLV are present. (Texte integral)

Pratap Kumar Pati - One of the best experts on this subject based on the ideXlab platform.

  • In vitro propagation of rose--a review.
    Biotechnology advances, 2005
    Co-Authors: Pratap Kumar Pati, Madhu Sharma, Siba Prasad Rath, Anil Sood, Paramvir Singh Ahuja
    Abstract:

    In vitro propagation of rose has played a very important role in rapid multiplication of cultivars with desirable traits and production of healthy and Disease-Free Plants. During the last several years, different approaches have been made for in vitro propagation of rose. Micropropagation using apical buds or nodal segments and understanding the specific requirements at different stages has been comprehensively covered in literature. New challenges for refinements of protocols for high rate of shoot multiplication and development of cost effective methods has gained importance in the recent past. Importance of liquid static culture for shoot proliferation and root induction for rose is also discussed in the present review. Further, the development of protocol for in vitro plant regeneration which is considered as most important step for successful implementation of various biotechnological techniques used for plant improvement programmes has been adequately addressed in literature. In rose, there are several reports which indicate rapid regeneration and multiplication through organogenesis or somatic embryogenesis. On the whole, the present review gives a consolidated account of in vitro propagation in rose.

J. M. Gatti - One of the best experts on this subject based on the ideXlab platform.

  • Disease-Free Plants for management of strawberry anthracnose crown rot.
    Plant Disease, 1992
    Co-Authors: T. B. Mcinnes, L. L. Black, J. M. Gatti
    Abstract:

    Anthracnose crown rot (ACR), caused by Colletotrichum fragariae, limited both plant and fruit production in strawberry summer nursery beds and production fields in Louisiana from 1986 to 1989 on most farms that used locally grown Plants. Pathogen-free Plants derived from tissue culture and increased in northeast Louisiana were provided to growers in southeast Louisiana for establishment of summer nursery beds. The pathogen-free strawberry Plants remained free of ACR in summer nursery beds planted apart from other beds established with locally grown transPlants (...)