My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in AJ

  1. Vol. 83 No. 3, p. 652-654
     
    Received: May 14, 1990
    Published: May, 1991


    * Corresponding author(s):
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/agronj1991.00021962008300030032x

Leaf Dark-Adapter for Measuring Chlorophyll Fluorescence in Situ during Daytime

  1. A. Selmani and
  2. C. E. Wassom 
  1. Dep. of Agronomy, Kansas State Univ., Manhattan, KS 66506

Abstract

Abstract

Chlorophyll a fluorescence is used as an indicator of stress damage to growing plants. Plants or plant samples first must be transported to a laboratory and dark adapted. If stress (e.g., drought has not been severe enough to permanently damage the photosynthetic apparatus, plants may recover during dark adaption and stress may not be detectable. In situ readings are more reliable. Dark adaptation takes place after the onset of total darkenss. The objective of this work was to develop a device that would enable the dark adaptation of plant leaves in situ during hours when stress could occur. A thin, light weight sheet of metal was developed to clip onto corn (Zea mays L.) leaves and allow dark adaptation during daylight. A sliding shutter was provided to expose a section of the leaf to light emitted from the fluorometer probe. Using the device, field measurements of daytime chlorophyll a fluorescence were obtained on attached leaves. Measurements were also taken at night on the same plants after dark-adaptation. In situ day measurements were significantly lower than those taken at night, indicating that stress during daytime influenced the fluorescence response and that plants tended to recover before nighttime readings were taken. Daytime in situ measurements provide an opportunity to detect non-permanent damage to the photosynlhetic apparatus that may show transient drought effects and lowel photosynthetic activity.

Cooperative investigations ofthe Kansas Agnc. Exp. Stn. and Dep. of Agronomy, Contribution no. 90-488-J of the Kansas Exp. Stn. Supported in part by the MidAmerica International Agricultural Consortium, Univ. of Nebraska, USDAID, Morocco Project No. 608-0136.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .