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High-throughput phenotyping of plant resistance to aphids by automated video tracking.

Kloth KJ, Ten Broeke CJ, Thoen MP, Hanhart-van den Brink M, Wiegers GL, Krips OE, Noldus LP, Dicke M, Jongsma MA - Plant Methods (2015)

Bottom Line: Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods.The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays.One video tracking platform could screen 100 samples in parallel.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands ; Laboratory of Plant Physiology, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands ; Plant Research International, Wageningen University and Research Center, P.O. Box 16, 6700 AA Wageningen, The Netherlands.

ABSTRACT

Background: Piercing-sucking insects are major vectors of plant viruses causing significant yield losses in crops. Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods.

Results: We have developed an automated video tracking platform that quantifies aphid feeding behaviour on leaf discs to assess the level of plant resistance. Through the analysis of aphid movement, the start and duration of plant penetrations by aphids were estimated. As a case study, video tracking confirmed the near-complete resistance of lettuce cultivar 'Corbana' against Nasonovia ribisnigri (Mosely), biotype Nr:0, and revealed quantitative resistance in Arabidopsis accession Co-2 against Myzus persicae (Sulzer). The video tracking platform was benchmarked against Electrical Penetration Graph (EPG) recordings and aphid population development assays. The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays. One video tracking platform could screen 100 samples in parallel.

Conclusions: Automated video tracking can be used to screen large plant populations for resistance to aphids and other piercing-sucking insects.

No MeSH data available.


Related in: MedlinePlus

Velocity thresholds for registration of probes. An example of how aphid feeding behaviour was measured using a resolution of 275 pixels per mm2. Subject states can be defined as ‘moving’ or ‘not moving’ by means of two thresholds: the start velocity at which the subject begins to move, and the stop velocity at which the state changes from moving to not moving. Probe starts were recorded if the velocity of the aphid’s centre point dropped below 0.02 mm/s for at least 10 seconds (α). Probe stops were recorded if the velocity of M. persicae aphids exceeded 0. 3 mm/s for at least 2 seconds (β), or 0.35 mm/s for at least 2 seconds in the case of winged N. ribisnigri aphids. To avoid premature probe endings due to short movements during probing (event γ), probe stops were only recorded when velocity increased above 0. 1 mm/s for more than 2 seconds. Figure adjusted from the EthoVision XT Reference Manual (version 8) [44].
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Fig2: Velocity thresholds for registration of probes. An example of how aphid feeding behaviour was measured using a resolution of 275 pixels per mm2. Subject states can be defined as ‘moving’ or ‘not moving’ by means of two thresholds: the start velocity at which the subject begins to move, and the stop velocity at which the state changes from moving to not moving. Probe starts were recorded if the velocity of the aphid’s centre point dropped below 0.02 mm/s for at least 10 seconds (α). Probe stops were recorded if the velocity of M. persicae aphids exceeded 0. 3 mm/s for at least 2 seconds (β), or 0.35 mm/s for at least 2 seconds in the case of winged N. ribisnigri aphids. To avoid premature probe endings due to short movements during probing (event γ), probe stops were only recorded when velocity increased above 0. 1 mm/s for more than 2 seconds. Figure adjusted from the EthoVision XT Reference Manual (version 8) [44].

Mentions: Automated video tracking of aphid feeding behaviour was performed using video tracking software and a stationary camera mounted above 20 no-choice arenas. We introduced one aphid onto each arena, consisting of an agar substrate almost completely covered by a leaf disc, and recorded 20 arenas simultaneously with a frame rate of 25 frames s−1 (Figure 1, Additional file 1: Figure S1). Because the aphid’s mouthparts were not visible in the multi-arena setup, we made the assumption that when the aphid’s centre point was located on the leaf disc and did not move, the aphid was penetrating the leaf tissue with its stylets. By assessing video images by eye, we defined velocity thresholds for the start and end of probing events of two aphid species, M. persicae and N. ribisnigri (Figure 2, Additional file 1: Figure S2). According to our observations, the software was more vulnerable to premature probe endings of N. ribisnigri due to body movements during probing (such as event γ in Figure 2). As this aphid species is somewhat larger (±1.9 mm body length, versus ± 1.7 mm for M. persicae), movements around the fixated mouth resulted in a higher tangential velocity, and therefore required a higher velocity threshold.Figure 1


High-throughput phenotyping of plant resistance to aphids by automated video tracking.

Kloth KJ, Ten Broeke CJ, Thoen MP, Hanhart-van den Brink M, Wiegers GL, Krips OE, Noldus LP, Dicke M, Jongsma MA - Plant Methods (2015)

Velocity thresholds for registration of probes. An example of how aphid feeding behaviour was measured using a resolution of 275 pixels per mm2. Subject states can be defined as ‘moving’ or ‘not moving’ by means of two thresholds: the start velocity at which the subject begins to move, and the stop velocity at which the state changes from moving to not moving. Probe starts were recorded if the velocity of the aphid’s centre point dropped below 0.02 mm/s for at least 10 seconds (α). Probe stops were recorded if the velocity of M. persicae aphids exceeded 0. 3 mm/s for at least 2 seconds (β), or 0.35 mm/s for at least 2 seconds in the case of winged N. ribisnigri aphids. To avoid premature probe endings due to short movements during probing (event γ), probe stops were only recorded when velocity increased above 0. 1 mm/s for more than 2 seconds. Figure adjusted from the EthoVision XT Reference Manual (version 8) [44].
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4318543&req=5

Fig2: Velocity thresholds for registration of probes. An example of how aphid feeding behaviour was measured using a resolution of 275 pixels per mm2. Subject states can be defined as ‘moving’ or ‘not moving’ by means of two thresholds: the start velocity at which the subject begins to move, and the stop velocity at which the state changes from moving to not moving. Probe starts were recorded if the velocity of the aphid’s centre point dropped below 0.02 mm/s for at least 10 seconds (α). Probe stops were recorded if the velocity of M. persicae aphids exceeded 0. 3 mm/s for at least 2 seconds (β), or 0.35 mm/s for at least 2 seconds in the case of winged N. ribisnigri aphids. To avoid premature probe endings due to short movements during probing (event γ), probe stops were only recorded when velocity increased above 0. 1 mm/s for more than 2 seconds. Figure adjusted from the EthoVision XT Reference Manual (version 8) [44].
Mentions: Automated video tracking of aphid feeding behaviour was performed using video tracking software and a stationary camera mounted above 20 no-choice arenas. We introduced one aphid onto each arena, consisting of an agar substrate almost completely covered by a leaf disc, and recorded 20 arenas simultaneously with a frame rate of 25 frames s−1 (Figure 1, Additional file 1: Figure S1). Because the aphid’s mouthparts were not visible in the multi-arena setup, we made the assumption that when the aphid’s centre point was located on the leaf disc and did not move, the aphid was penetrating the leaf tissue with its stylets. By assessing video images by eye, we defined velocity thresholds for the start and end of probing events of two aphid species, M. persicae and N. ribisnigri (Figure 2, Additional file 1: Figure S2). According to our observations, the software was more vulnerable to premature probe endings of N. ribisnigri due to body movements during probing (such as event γ in Figure 2). As this aphid species is somewhat larger (±1.9 mm body length, versus ± 1.7 mm for M. persicae), movements around the fixated mouth resulted in a higher tangential velocity, and therefore required a higher velocity threshold.Figure 1

Bottom Line: Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods.The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays.One video tracking platform could screen 100 samples in parallel.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Entomology, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands ; Laboratory of Plant Physiology, Wageningen University, P.O. Box 16, 6700 AA Wageningen, The Netherlands ; Plant Research International, Wageningen University and Research Center, P.O. Box 16, 6700 AA Wageningen, The Netherlands.

ABSTRACT

Background: Piercing-sucking insects are major vectors of plant viruses causing significant yield losses in crops. Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods.

Results: We have developed an automated video tracking platform that quantifies aphid feeding behaviour on leaf discs to assess the level of plant resistance. Through the analysis of aphid movement, the start and duration of plant penetrations by aphids were estimated. As a case study, video tracking confirmed the near-complete resistance of lettuce cultivar 'Corbana' against Nasonovia ribisnigri (Mosely), biotype Nr:0, and revealed quantitative resistance in Arabidopsis accession Co-2 against Myzus persicae (Sulzer). The video tracking platform was benchmarked against Electrical Penetration Graph (EPG) recordings and aphid population development assays. The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays. One video tracking platform could screen 100 samples in parallel.

Conclusions: Automated video tracking can be used to screen large plant populations for resistance to aphids and other piercing-sucking insects.

No MeSH data available.


Related in: MedlinePlus