Elucidating the regulatory mechanisms of envi-ronmental factors on seed dormancy and germination will provide guidance for tree regeneration. Toward understand-ing the coupled effect of light and temperature on dormancy release and germination of Pinus koraiensis seeds, we set up three light conditions (L200: 200 μmol m ?2 s ?1 , L20: 20 μmol m ?2 s ?1 , L0: 0 μ m ?2 s ?1 ) and four storage tem-peratures [T-5: ? 5 ℃ (50 days), T5: ? 5 ℃ (50 days) + 5 ℃ (50 days), T25: ? 5 ℃(50 days) + 5 ℃ (50 days) + 25 ℃ (50 days), T15: ? 5 ℃ (50 days) + 5 ℃ (50 days) + 25 ℃ (50 days) + 15 ℃ (50 days)] using imbibed seeds, then quan-tified phytohormones gibberellic acid (GA 3 ) and abscisic acid (ABA) during the stratification. Germination percent-age ( G P ), mean germination time ( T M ), and germination value ( G V ) under 25/15 ℃ temperature and the three light conditions were then determined. Phytohormone levels and germination performances were significantly affected by light and temperature. No consistent trend was found between the phytohormone levels and G P caused by light levels. Under the three light conditions, ABA concentrations in the embryo and endosperm decreased as storage tempera-ture shifted from T-5 to T25 and increased from T25 to T15; GA 3 decreased in nearly all four storage temperatures. G P reached 40-60％ in T25 storage without light irradiance. In the three light conditions, G P and G V were higher at T5 and T25 than at T-5 and T15; so T5 and T25 are considered as optimum storage temperatures for dormancy release and ger-mination. At optimum temperatures, light (L200, L20) sig-nificantly increased the G P and G V compared with the dark (L0). At L200 and L20, significant negative correlations between G V and the ABA concentrations and positive cor-relations between G V and GA/ABA in the seed embryo were found. Temperature played a more important role in primary dormancy release and germination; light was unnecessary for primary dormancy release. Light facilitated seed ger-mination at optimum temperatures. The dormancy release and germination of P. koraiensis seeds were controlled by a decrease in ABA concentrations or an increase in GA/ABA induced by temperature variations.

Min Zhang;Jiaojun Zhu

Institute of Applied Ecology,Chinese Academy of Sciences, Shenyang 110016,People's Republic of China;Qingyuan Forest CERN,Chinese Academy of Sciences, Shenyang 110016,People's Republic of China

林业研究（英文版）

[1]Min Zhang;Jiaojun Zhu-.The coupled effect of light and temperature on dormancy release and germination of Pinus koraiensis seeds)[J].林业研究（英文版）,2022(04):1135-1144

imbibed,Phytohormone

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