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Diel leaf growth of soybean: a novel method to analyze two-dimensional leaf expansion in high temporal resolution based on a marker tracking approach (Martrack Leaf).

Mielewczik M, Friedli M, Kirchgessner N, Walter A - Plant Methods (2013)

Bottom Line: The beads are mechanically constricted to the focal plane of a camera.Algorithms are provided to the entire community interested in using such approaches.It will be beneficial for the further elucidation of genotype x environment x management interactions affecting leaf growth processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: ETH Zürich, Institute of Agricultural Sciences, Universitätstr, 2, CH-8092 Zürich, Switzerland. norbert.kirchgessner@usys.ethz.ch.

ABSTRACT

Background: We present a novel method for quantitative analysis of dicot leaf expansion at high temporal resolution. Image sequences of growing leaves were assessed using a marker tracking algorithm. An important feature of the method is the attachment of dark beads that serve as artificial landmarks to the leaf margin. The beads are mechanically constricted to the focal plane of a camera. Leaf expansion is approximated by the increase in area of the polygon defined by the centers of mass of the beads surrounding the leaf. Fluctuating illumination conditions often pose serious problems for tracking natural structures of a leaf; this problem is circumvented here by the use of the beads.

Results: The new method has been used to assess leaf growth in environmental situations with different illumination conditions that are typical in agricultural and biological experiments: Constant illumination via fluorescent light tubes in a climate chamber, a mix of natural and artificial illumination in a greenhouse and natural illumination of the situation on typical summer days in the field. Typical features of diel (24h) soybean leaf growth patterns were revealed in all three conditions, thereby demonstrating the general applicability of the method. Algorithms are provided to the entire community interested in using such approaches.

Conclusions: The implementation Martrack Leaf presented here is a robust method to investigate diel leaf growth rhythms both under natural and artificial illumination conditions. It will be beneficial for the further elucidation of genotype x environment x management interactions affecting leaf growth processes.

No MeSH data available.


Related in: MedlinePlus

Diel growth pattern of soybean leaves in the climate chamber. (A, B, C) Relative growth rates (RGR) of three soybean leaves from day 1 to day 4. (D) Relative humidity (%) and (E) temperature (°C) throughout the measurements.
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Figure 6: Diel growth pattern of soybean leaves in the climate chamber. (A, B, C) Relative growth rates (RGR) of three soybean leaves from day 1 to day 4. (D) Relative humidity (%) and (E) temperature (°C) throughout the measurements.

Mentions: It was therefore beneficial to introduce a bright background below the leaf, thereby increasing contrast between beads and background (see Figures 1 D+E and 2). Experiments performed in climate chambers showed clearly oscillating temporal leaf growth patterns (see Figure 6) RGR increased during the day, reaching a maximum at day-night-transition. At night, RGR declined again. Short-term fluctuations of RGR were present, but the overall diel pattern remained constant throughout several days.


Diel leaf growth of soybean: a novel method to analyze two-dimensional leaf expansion in high temporal resolution based on a marker tracking approach (Martrack Leaf).

Mielewczik M, Friedli M, Kirchgessner N, Walter A - Plant Methods (2013)

Diel growth pattern of soybean leaves in the climate chamber. (A, B, C) Relative growth rates (RGR) of three soybean leaves from day 1 to day 4. (D) Relative humidity (%) and (E) temperature (°C) throughout the measurements.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750653&req=5

Figure 6: Diel growth pattern of soybean leaves in the climate chamber. (A, B, C) Relative growth rates (RGR) of three soybean leaves from day 1 to day 4. (D) Relative humidity (%) and (E) temperature (°C) throughout the measurements.
Mentions: It was therefore beneficial to introduce a bright background below the leaf, thereby increasing contrast between beads and background (see Figures 1 D+E and 2). Experiments performed in climate chambers showed clearly oscillating temporal leaf growth patterns (see Figure 6) RGR increased during the day, reaching a maximum at day-night-transition. At night, RGR declined again. Short-term fluctuations of RGR were present, but the overall diel pattern remained constant throughout several days.

Bottom Line: The beads are mechanically constricted to the focal plane of a camera.Algorithms are provided to the entire community interested in using such approaches.It will be beneficial for the further elucidation of genotype x environment x management interactions affecting leaf growth processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: ETH Zürich, Institute of Agricultural Sciences, Universitätstr, 2, CH-8092 Zürich, Switzerland. norbert.kirchgessner@usys.ethz.ch.

ABSTRACT

Background: We present a novel method for quantitative analysis of dicot leaf expansion at high temporal resolution. Image sequences of growing leaves were assessed using a marker tracking algorithm. An important feature of the method is the attachment of dark beads that serve as artificial landmarks to the leaf margin. The beads are mechanically constricted to the focal plane of a camera. Leaf expansion is approximated by the increase in area of the polygon defined by the centers of mass of the beads surrounding the leaf. Fluctuating illumination conditions often pose serious problems for tracking natural structures of a leaf; this problem is circumvented here by the use of the beads.

Results: The new method has been used to assess leaf growth in environmental situations with different illumination conditions that are typical in agricultural and biological experiments: Constant illumination via fluorescent light tubes in a climate chamber, a mix of natural and artificial illumination in a greenhouse and natural illumination of the situation on typical summer days in the field. Typical features of diel (24h) soybean leaf growth patterns were revealed in all three conditions, thereby demonstrating the general applicability of the method. Algorithms are provided to the entire community interested in using such approaches.

Conclusions: The implementation Martrack Leaf presented here is a robust method to investigate diel leaf growth rhythms both under natural and artificial illumination conditions. It will be beneficial for the further elucidation of genotype x environment x management interactions affecting leaf growth processes.

No MeSH data available.


Related in: MedlinePlus