Volume 7
Issue 1
Horticulture
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Available Online: http://www.ejpau.media.pl/volume7/issue1/horticulture/abs-05.html
CHLOROPHYLL α FLUORESCENCE AS A DIAGNOSTIC TOOL FOR ASSESSMENT OF APPLE RESISTANCE AGAINST TWO-SPOTTED SPIDER MITE (TETRANYCHUS URTICAE KOCH.)
Wojciech Warabieda, Bożena Borkowska
ABSTRACT
The chlorophyll fluorescence measurements were used as a method of assessing the influence of Tetranychus urticae feeding on photosynthetic apparatus of ‘Lobo’ and ‘Jester’ apple cultivars. The photochemical efficiency measured with such parameters like: the initial fluorescence (F0), the maximum fluorescence (Fm), the ratio of variable to maximum fluorescence (Fv/Fm), and the area under the fluorescence curve (Sc) decreases continuously with increasing infestation by mites. The only parameter not influenced by mites feeding was the half-rise time from F0 to Fm (Tfm). Antennas of both ‘Lobo’ and ‘Jester’ cvs. were similarly injured by mites (comparable decrease of F0) but photochemical reactions of the harvested energy of ‘Jester’ leaves were less influenced by this pest (lower decrease for Fv/Fm). It suggests a higher tolerance of the photosynthetic apparatus of ‘
Key words: apple, biotic stress, mite, resistance, chlorophyll fluorescence.