Ozone effects on dry matter partitioning and chlorophyll fluorescence during plant development of wheat

✍ Scribed by G. Soja; A.-M. Soja

• Publisher: Springer Netherlands
• Year: 1995
• Tongue: English
• Weight: 382 KB
• Volume: 85
• Category: Article
• ISSN: 0049-6979
• DOI: 10.1007/bf00477187

✦ Synopsis

In closed-chamber fumigation experiments dry mailer partitioning and chlorophyll fluorescence of wheat were studied, analysing the effects of ozone during different stages of plant development. Ozone causes enhanced leaf senescence, leading to a loss of green leaf area and, consequently to a decreased supply of assimilates, affe~.Jng (in in<xeasing order of severeness) stem, ear and grain productivity because of reduced storage pools for translocation. Leaves of plants before shooting stage were most sensitive but the lack of green leaf area aider ear emergence had the most pronounced effects on grain yield.

Measurements of photochemical capacity showed that evidence for negative ozone effects could be found in changes of chlorophyll fluorescence parameters in leaf sections not yet showing visible ozone injury. Negative effe~s on photosyrtthesis were more distinct with increasing accumulated ozone dose, with increasing age of leaf tissue and with increasing ozone sensitivity of the cuRivar. The changes in chlorophyll fluorescence are most likely to be explained by a decreased pool size ofplastoquinones caused by ozone.