Liaoning Province Sand Fixation and Afforestation Research Institute

Fuxin, China

Liaoning Province Sand Fixation and Afforestation Research Institute

Fuxin, China
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Meng P.,Agricultural University of Hebei | Meng P.,Liaoning Province Sand Fixation and Afforestation Research Institute | Li Y.-L.,Agricultural University of Hebei | Zhang B.-X.,Liaoning Province Sand Fixation and Afforestation Research Institute
Chinese Journal of Applied Ecology | Year: 2013

For the popularization of Pinus densiflora var. zhangwuensis, a new afforestation tree species on the desertified and salinized-alkalized lands in Northern China, and to evaluate the salinity-alkalinity tolerance of the tree species and to better understand the tolerance mechanisms, a pot experiment with 4-year old P. densiflora var. zhangwuensis and P. sylvestris var. mongolica was conducted to study their seedlings growth and physiological and biochemical indices under the effects of three types salt (NaCl, Na2CO3, and NaHCO3) stresses and of alkali (NaOH) stress. Under the salt-alkali stresses, the injury level of P. densiflora var. zhangwuensis was lower, and the root tolerance index was higher. The leaf catalase (CAT) activity increased significantly by 22.6 times at the most, as compared with the control; the leaf malondialdehyde (MDA) content had no significant increase; the leaf chlorophyll (Chl) content had a smaller decrement; and the leaf water content (LWC) increased slightly. P. sylvestris var. mongolica responded differently to the salt-alkali stresses. Its leaf CAT activity had less change, MDA content increased significantly, Chl content had significant decrease, and LWC decreased slightly. It was suggested that P. densiflora var. zhangwuensis had a greater salinity-alkalinity tolerance than P. sylvestris var. mongolica. The higher iron concentration in P. densiflora var. zhangwuensis needles enhanced the CAT activity and Chl content, whereas the higher concentrations of zinc and copper were associated with the stronger salinity-alkalinity tolerance.


Meng P.,Liaoning Province Sand Fixation and Afforestation Research Institute | An Y.N.,Liaoning Province Sand Fixation and Afforestation Research Institute | Bai X.F.,Liaoning Province Sand Fixation and Afforestation Research Institute
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2016

Pinus densiflorahas grown in the southern Horqin Sandy Land, China, for 50 years, but little is known about its field performance in this region, and nothing is known about its photosynthetic physiology. To understand the physiological characteristics and mechanisms of photosynthesis in P. densiflora, mature trees were compared with the same-aged trees of Pinus sylvestris var. mongolica (the control), and the growth characteristics of both species were investigated. Photosynthetic characteristics were analyzed with a Li-6400 system, and fast chlorophyll a fluorescence transients (OJIP) were analyzed with a Pocket PEA plant efficiency analyzer. Growth and biomass of mature P. densiflora was greater than that of P. sylvestris var. mongolica. This was closely related to stronger photosynthesis in P. densiflora, including a higher maximum net photosynthetic rate (Pmax, 10.376 μmol CO2 m-2 s-1) and a large range of light adaptation with high light saturation point and low light compensation point. The dark respiration rate (Rd) of P. densiflora was low, leading to higher photosynthetic efficiency (Pmax/Rd). Diurnal changes in the net photosynthetic rate (Pn) of P. densiflora ranged from 3.290 to 7.349 μmol CO2 m-2 s-1, and the mean Pn was 4.902 μmol CO2 m-2 s-1, which was 36.2% higher than that of P. sylvestris var. mongolica. The Pnof P. densiflora at each time point was significantly higher than that of P. sylvestris var. mongolica, except at 14: 00 and 16: 00. The transpiration rate of P. densiflora was 34.8% lower than that of P. sylvestris var. mongolica, and its water use efficiency was 2.06-fold greater than that of P. sylvestris var. mongolica. The Pnof P. densiflora remained high when stomatal conductance was low. Compared with P. sylvestris var. mongolica, P. densiflora was less susceptible to dynamic photoinhibition, showing slight photoinhibition only at a PPFD of 2000 μmol m-2 s-1, when Pnwas 91.4% of the maximum. The chlorophyll content in P. densiflora needles was 1.380 mg/g, double that in needles of P. sylvestris var. mongolica. The JIP test was used to reveal the mechanism for the strong photosynthesis of P. densiflora and showed that in the range from 0 to P phase, the relative variable fluorescence value of P. densiflora was generally low. This low value indicated that little energy was dissipated via the electron transfer chain, so that more energy could be used for photochemistry. The two species reached fluorescence maxima at different times under saturating illumination: 700 ms for P. densiflora and 900 ms for P. sylvestris var. mongolica. The phenomenological energy fluxes per excited cross section (CS) were calculated; these indexes showed that, compared with P. sylvestris var. mongolica, P. densiflora had a higher density of reaction centers (RC/CSo, RC/CSm), a greater proportion of photon flux absorbed by the antenna pigments (ABS/CSo, ABS/CSm), higher trapping flux to the reaction center (TRo/CSo), and used more energy for electron transfer (ETo/ CSo). These attributes led to its higher performance indexes. The PI(ABS/CSo/CSm) of P. densiflora were 1.42-, 1.65-, and 1.63- fold those of P. sylvestris var. mongolica, respectively. Together, these results suggest that the growth and photosynthetic performance of P. densiflora are better than those of P. sylvestris var. mongolica in the Horqin Sandy Land environment. This conclusion provides the theoretical basis for the expansion of P. densiflora cultivation in this region. © 2016. Shengtai Xuebao Acta Ecologica Sinica. All Rights Reserved.


Meng P.,Liaoning Province Sand Fixation and Afforestation Research Institute | Bai X.,Liaoning Province Sand Fixation and Afforestation Research Institute | Li H.,Liaoning Province Sand Fixation and Afforestation Research Institute | Song X.,Liaoning Province Sand Fixation and Afforestation Research Institute | Zhang X.,Liaoning Province Sand Fixation and Afforestation Research Institute
Journal of Forestry Research | Year: 2015

Pinus densiflora var. zhangwuensis grows fast, and its drought and salinity resistance are better than Pinus sylvestris var. mongolica. We compared cold hardiness and mechanisms of cold hardiness between the two species, to provide a theoretical basis for promoting and applying P. densiflora var. zhangwuensis in cold regions. A cold stress experiment was carried out on 3-year-old plantlets of P. densiflora var. zhangwuensis and P. sylvestris var. mongolica after hardening at five temperature regimes, 5, −10, −20, −40, and −60 °C, respectively. Some indices of needle samples for both species were measured, such as relative conductivity (REL), maximum photochemical efficiency (Fv/Fm), malondialdehyde (MDA), catalase (CAT), proline (Pro), soluble sugar (SS), and stomata density. REL and MDA values of both species after hardening had the same trend of increasing, but the trend was opposite in Fv/Fm value with increasing cold stress. Compared with P. sylvestris var. mongolica, the P. densiflora var. zhangwuensis had smaller increases in REL and MDA, and a smaller decline in Fv/Fm during cold stress. Compared to the control, REL growth of P. densiflora var. zhangwuensis and P. sylvestris var. mongolica at −60 °C were 0.41 and 0.60, and MDA growth was 29.94 mol g−1 FW and 47.80 mol g−1 FW, and Fv/Fm declines were 0.08 and 0.27. Half-lethal temperatures (LT50) calculated by logistic equation for P. densiflora var. zhangwuensis and P. sylvestris var. mongolica were −58.23 and −50.34 °C, respectively. These data suggest that cold resistance of P. densiflora var. zhangwuensis is stronger than that of P. sylvestris var. mongolica. Cold-resistance mechanisms of the two species differed. In response to cold stress, P. sylvestris var. mongolica had strong osmotic adjustment ability because of higher Pro and SS content, while P. densiflora var. zhangwuensis had strong antioxidant ability due to stronger CAT activity. Stomata density and diameter of P. densiflora var. zhangwuensis were smaller, as were single leaf area and number of leaves per plant, both characteristics promoting survival in a cold environment. Greater shoot height and total biomass of seedlings of P. densiflora var. zhangwuensis might be another reason for its stronger cold tolerance. © 2015, Northeast Forestry University and Springer-Verlag Berlin Heidelberg.


Wang K.,LIAONING Technical University | Lei H.,LIAONING Technical University | Liu J.-H.,Liaoning Province Sand Fixation and Afforestation Research Institute
Chinese Journal of Applied Ecology | Year: 2016

In the present study, the effects of spring drought stress on physiological characteristics of leaves and roots for Populus alba, Ulmus pumila, Syringa oblata and Prunus sibirica were analyzed in Northwest Liaoning Province. The relationships between leaves and roots under drought stress were explored, and drought resistance of the four tree species was evaluated with the method of subordinate function and the gray correlative analysis. The results showed that there were significant differences in osmotic substances contents (soluble sugar, soluble protein and proline), antioxidative enzymes activities (SOD, POD and CAT) and malondialdehyde content among the four tree species and different organs (leaves and roots) (P<0.05). The average subordinative value in leaves increased in a sequence of P. sibirica (0.245), P. alba (0.346), S. oblata (0.412) and U. pumila (0.673), but it increased in roots in an order of U. pumila (0.315), P. sibirica (0.383), S. oblata (0.552) and P. alba (0.558). Meanwhile, the average subordinative value in leaves of P. alba, S. oblata and P. sibirica was lower than in roots, but it was higher in leaves than in roots of U. pumila. The association between physiological indexes and drought resistance showed an order of malondialdehyde > SOD > CAT > soluble protein > proline > soluble sugar > POD in leaves, and an order of malondialdehyde > soluble protein > soluble sugar > CAT > POD > proline > SOD in roots. These results indicated that the drought-resistant capability was different in leaves and roots of the four tree species. The roles of drought-resistance indexes were different between leaves and roots of the four tree species. Different management measures should be selected according to different organs of various tree species. © 2016, Science Press. All right reserved.

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