Abstract:

In order to teat the induced function of exogenous jasmonates on larch tannins, variation of tannin content in needles of two-year-old Larix gmelinii and L. olgensis seedlings was analyzed by vanillin-colorimetry determination after spraying treatments with the different concentrations of exogenous jasmonates. The results showed after being treated with jasmonic acid (JA), methyl jasmonate (MJA) and (Z)-jasmone (ZJ), tannin content in needles of the two larch species increased or decreased significantly than the control, and the variation lasted for 10～20 days. ZJ had stronger effect on the variation of tannin content in L. gmelinii needles than MJA and JA, whereas the all three jasmonate significantly affected tannin content in L. olgensis needles.Tannin content in Larix gmelinii needles treated with the 0.01 mmol·L^-1 ZJ, 0.01 mmol·L^-1 MJA and 1 mmol·L^-1 JA changed significantly, while the variation of tannin content in L. olgensis needles was obviously affected by 0.01 mmol·L^-1 MJA and 1 mmol·L^-1 JA. Compared with that of tannin content in L. olgensis needles, variational degree of L. gmelinii needles were much higher on inducement of the three jasmonates. It is concluded that the treatments with exogenous jasmonates could induce increase or decrease of tannin content in the larch systemically, and the effects were relatively persistent. The stimulus response of L. gmelinii was stronger than that of L. olgensis to exogenous jasmonates.

Key words: larch, exogenous jasmonates, induced function, stimulus response, tannin