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A New Method for in Situ Measurement of Bt-Maize Pollen Deposition on Host-Plant Leaves.

Hofmann F, Otto M, Kuhn U, Ober S, Schlechtriemen U, Vögel R - Insects (2011)

Bottom Line: These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves.The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software), which can be used in combination with a notebook in the field.Maize pollen could be correctly identified and pollen deposition as well as the spatial heterogeneity of maize pollen deposition was recorded on maize and different lepidopteran host plants (Centaurea scabiosa, Chenopodium album, Rumex spp., Succina pratensis and Urtica dioica) growing adjacent to maize fields.

View Article: PubMed Central - PubMed

Affiliation: TIEM Integrated Environmental Monitoring GbR, Nörten-Hardenberg/Bremen, Germany. f.hofmann@oekologiebuero.de.

ABSTRACT
Maize is wind pollinated and produces huge amounts of pollen. In consequence, the Cry toxins expressed in the pollen of Bt maize will be dispersed by wind in the surrounding vegetation leading to exposure of non-target organisms (NTO). NTO like lepidopteran larvae may be affected by the uptake of Bt-pollen deposited on their host plants. Although some information is available to estimate pollen deposition on host plants, recorded data are based on indirect measurements such as shaking or washing off pollen, or removing pollen with adhesive tapes. These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves. Here, we present a new method for recording in situ the amount and the distribution of Bt-maize pollen deposited on host plant leaves. The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software), which can be used in combination with a notebook in the field. The method was evaluated during experiments in 2008 to 2010. Maize pollen could be correctly identified and pollen deposition as well as the spatial heterogeneity of maize pollen deposition was recorded on maize and different lepidopteran host plants (Centaurea scabiosa, Chenopodium album, Rumex spp., Succina pratensis and Urtica dioica) growing adjacent to maize fields.

No MeSH data available.


Related in: MedlinePlus

Image of upper leaf side of Centaurea scabiosa taken in situ with Dino-Lite microscope (200×). Maize pollen can be distinguished from other pollen species by its relatively large size between 80–120 μm, color, shape and structure of the exine. Measurements are given by Dino Capture software.
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f2-insects-02-00012: Image of upper leaf side of Centaurea scabiosa taken in situ with Dino-Lite microscope (200×). Maize pollen can be distinguished from other pollen species by its relatively large size between 80–120 μm, color, shape and structure of the exine. Measurements are given by Dino Capture software.

Mentions: The size of the sampling spot varies with the magnification of the microscope between approximately 20 mm2 (50×) and 5 mm2 (200×) and was calibrated before measurement. A magnification of 200× is preferable for most pollen counts as maize pollen can be more easily identified with this magnification (Figure 2). Pollen analysis was done visually. The use of image analysis to quantify pollen seems possible but is restricted to occurrences of lower pollen densities when pollen does not overlap. Such overlap will interfere with automatic image analysis and result in additional effort for quality control, including a visual re-analysis of images. Our first aim was to test whether maize pollen can be identified and distinguished from other pollen-types and whether the method is suitable for in situ measurements of different plant and leaf types. Criteria for the selection of plant species were the availability in and close to the maize fields, leaf shape, presence/absence of leaf hairs, and the plant's potential role as host plant for lepidopteran larvae. The plant species selected, apart from maize, were stinging nettle (Urtica dioica), goosefoot (Chenopodium album), two dock species (Rumex crispus and R. obtusifolius), devil's scabious (Succisa pratensis), and knappweed (Centaurea scabiosa).


A New Method for in Situ Measurement of Bt-Maize Pollen Deposition on Host-Plant Leaves.

Hofmann F, Otto M, Kuhn U, Ober S, Schlechtriemen U, Vögel R - Insects (2011)

Image of upper leaf side of Centaurea scabiosa taken in situ with Dino-Lite microscope (200×). Maize pollen can be distinguished from other pollen species by its relatively large size between 80–120 μm, color, shape and structure of the exine. Measurements are given by Dino Capture software.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553420&req=5

f2-insects-02-00012: Image of upper leaf side of Centaurea scabiosa taken in situ with Dino-Lite microscope (200×). Maize pollen can be distinguished from other pollen species by its relatively large size between 80–120 μm, color, shape and structure of the exine. Measurements are given by Dino Capture software.
Mentions: The size of the sampling spot varies with the magnification of the microscope between approximately 20 mm2 (50×) and 5 mm2 (200×) and was calibrated before measurement. A magnification of 200× is preferable for most pollen counts as maize pollen can be more easily identified with this magnification (Figure 2). Pollen analysis was done visually. The use of image analysis to quantify pollen seems possible but is restricted to occurrences of lower pollen densities when pollen does not overlap. Such overlap will interfere with automatic image analysis and result in additional effort for quality control, including a visual re-analysis of images. Our first aim was to test whether maize pollen can be identified and distinguished from other pollen-types and whether the method is suitable for in situ measurements of different plant and leaf types. Criteria for the selection of plant species were the availability in and close to the maize fields, leaf shape, presence/absence of leaf hairs, and the plant's potential role as host plant for lepidopteran larvae. The plant species selected, apart from maize, were stinging nettle (Urtica dioica), goosefoot (Chenopodium album), two dock species (Rumex crispus and R. obtusifolius), devil's scabious (Succisa pratensis), and knappweed (Centaurea scabiosa).

Bottom Line: These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves.The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software), which can be used in combination with a notebook in the field.Maize pollen could be correctly identified and pollen deposition as well as the spatial heterogeneity of maize pollen deposition was recorded on maize and different lepidopteran host plants (Centaurea scabiosa, Chenopodium album, Rumex spp., Succina pratensis and Urtica dioica) growing adjacent to maize fields.

View Article: PubMed Central - PubMed

Affiliation: TIEM Integrated Environmental Monitoring GbR, Nörten-Hardenberg/Bremen, Germany. f.hofmann@oekologiebuero.de.

ABSTRACT
Maize is wind pollinated and produces huge amounts of pollen. In consequence, the Cry toxins expressed in the pollen of Bt maize will be dispersed by wind in the surrounding vegetation leading to exposure of non-target organisms (NTO). NTO like lepidopteran larvae may be affected by the uptake of Bt-pollen deposited on their host plants. Although some information is available to estimate pollen deposition on host plants, recorded data are based on indirect measurements such as shaking or washing off pollen, or removing pollen with adhesive tapes. These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves. Here, we present a new method for recording in situ the amount and the distribution of Bt-maize pollen deposited on host plant leaves. The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software), which can be used in combination with a notebook in the field. The method was evaluated during experiments in 2008 to 2010. Maize pollen could be correctly identified and pollen deposition as well as the spatial heterogeneity of maize pollen deposition was recorded on maize and different lepidopteran host plants (Centaurea scabiosa, Chenopodium album, Rumex spp., Succina pratensis and Urtica dioica) growing adjacent to maize fields.

No MeSH data available.


Related in: MedlinePlus