A comparative evaluation of the consequences of Phytoptus tetratrichus Nalepa (Acari: Eriophyoidea) feeding on the content and tissue distribution of polyphenolic compounds in leaves of different linden taxa

摘要

Here we report a comparative study on the content and tissue distribution of polyphenols in leaves of small-leaved linden (Tilia cordata Mill.) and silver linden (Tilia tomentosa Moench) differentially galled by Phytoptus tetratrichus Nalepa (Acari: Eriophyidae). Data showed that at the beginning of the season (early July): (1) the native level of leaf flavonoids (flavonols, anthocyanins, tannins) varied significantly being higher in T. cordata than in T. tomentosa, (2) eriophyoid mite abundance was markedly lower on leaves of T. cordata with 4-fold higher levels of anthocyanins and 6-fold higher levels of tannins than on leaves of T. tomentosa, (3) in relation to linden taxa and mite/gall density, the content of flavonoids altered differently: in mite-galled leaves of T. cordata both flavonols and tannins accumulated markedly (up to 1% of leaf dry weight), whereas in galled leaves of T. tomentosa the increase of tannins and flavonols was much weaker (up to 0.6% of leaf dry weight), (4) due to P. tetratrichus feeding, the content of anthocyanins in T. cordata leaves decreased, while in T. tomentosa it did not change or it increased, depending on gall density. Results obtained suggest that at the beginning of the season T. cordata is a less suitable host for P. tetratrichus than T. tomentosa due to the relatively high amount of native leaf anthocyanins and tannins. Since the most responsive class of leaf flavonoids to P. tetratrichus feeding were tannins and flavonols, they are proposed as putative factors negatively affecting the performance of P. tetratrichus.