Bark beetles Tomicus yunnanensis and T.minor are two important pests of Pinus yunnanensis and can cause massive death of pine trees.In this study,we examined several traits related to photosynthesis in P.yunnanensis a...Bark beetles Tomicus yunnanensis and T.minor are two important pests of Pinus yunnanensis and can cause massive death of pine trees.In this study,we examined several traits related to photosynthesis in P.yunnanensis and their relationship with antibiotic defense responses after joint attack by the two bark beetles at the shoot and the trunk stages.When shoots were attacked by the beetles,the abundance of chlorophylls,carotenoids,and the rates of net photosynthesis(Pn)and transpiration(E)decreased in needles,while the levels of superoxide dismutase and malondialdehyde remained unchanged in both needles and phloem.The activity of peroxidases also remained unchanged in needles,but increased in phloem.The activity of catalases increased in both needles and phloem.When trunks were attacked by the bark beetles,chlorophyll abundance,Pn,E,and antioxidative enzyme activities all declined,and the declines were more pronounced than in the attacked shoots.A decrease in protein concentrations was also observed in needles and phloem from the attacked pines.Attack on shoots by the bark beetles suppressed host defense and provided a favorable environment for larval growth and development,resulting in long-term decline of pine growth potential.The results suggest that attacks on trunks by beetles caused more severe damage to host trees than attacks on shoots.展开更多
Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Se...Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Seed germination and seedling growth traits at the nursery stage were investigated at the population level. We evaluated relationships between pairs of measured traits as well as the association between measured traits and geo- climatic variables including longitude, latitude, elevation, temperature and precipitation. Seedling growth showed significant differences although a low magnitude of variation was found in the seed germination traits among the populations. Some populations with strong and stable growth （e.g., the Baoshan population） may be selected as superior seed sources for regeneration and reforestation. Germination percentage was negatively correlated with elevation, and positively with precipitation. In addition, germination index, vigor index and seedling height were positively correlated with precipitation. Seed germination index, cotyledon number and length, and seedling diameter were significantly and positively correlated with seed weight. Strong correlations between pairs of traits will be helpful in early evaluations for the selection of certain prominent traits.展开更多
基金supported by the Fundamental Scientific Research Fund for Central Non-profit Research Institute(Grant No.CAFYBB2016MA006)the Public Welfare Special Fund Project of Forestry Industry of State Forestry Administration of China(Grant No.200904052)
文摘Bark beetles Tomicus yunnanensis and T.minor are two important pests of Pinus yunnanensis and can cause massive death of pine trees.In this study,we examined several traits related to photosynthesis in P.yunnanensis and their relationship with antibiotic defense responses after joint attack by the two bark beetles at the shoot and the trunk stages.When shoots were attacked by the beetles,the abundance of chlorophylls,carotenoids,and the rates of net photosynthesis(Pn)and transpiration(E)decreased in needles,while the levels of superoxide dismutase and malondialdehyde remained unchanged in both needles and phloem.The activity of peroxidases also remained unchanged in needles,but increased in phloem.The activity of catalases increased in both needles and phloem.When trunks were attacked by the bark beetles,chlorophyll abundance,Pn,E,and antioxidative enzyme activities all declined,and the declines were more pronounced than in the attacked shoots.A decrease in protein concentrations was also observed in needles and phloem from the attacked pines.Attack on shoots by the bark beetles suppressed host defense and provided a favorable environment for larval growth and development,resulting in long-term decline of pine growth potential.The results suggest that attacks on trunks by beetles caused more severe damage to host trees than attacks on shoots.
基金supported by the Natural Science Foundation of China(NSFC 31360189 and NSFC 31070591)
文摘Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Seed germination and seedling growth traits at the nursery stage were investigated at the population level. We evaluated relationships between pairs of measured traits as well as the association between measured traits and geo- climatic variables including longitude, latitude, elevation, temperature and precipitation. Seedling growth showed significant differences although a low magnitude of variation was found in the seed germination traits among the populations. Some populations with strong and stable growth （e.g., the Baoshan population） may be selected as superior seed sources for regeneration and reforestation. Germination percentage was negatively correlated with elevation, and positively with precipitation. In addition, germination index, vigor index and seedling height were positively correlated with precipitation. Seed germination index, cotyledon number and length, and seedling diameter were significantly and positively correlated with seed weight. Strong correlations between pairs of traits will be helpful in early evaluations for the selection of certain prominent traits.
