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Fan X.M.,Central South University of forestry and Technology | Yuan D.Y.,Central South University of forestry and Technology | Yang F.X.,Hunan University of Technology | Tian X.M.,Hunan Forest Botanical Garden | And 3 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015

Eight-year-old Castanea henryi cv. Huali 4 (Fagaceae) trees were studied in order to explore the relationship between tree shape and light use by C. henryi, and provide scientific advice on the cultivation and management of this species. An illuminometer, a chlorophyll meter and a portable photosynthesis system were used to measure relative light intensity in different tiers of the canopy, and the diurnal course of ecophysiological and photosynthetic parameters were measured to ascertain the effects of different tree forms on the photosynthetic performance and yield of C. henryi. The results showed that: 1) the relative light intensities of the three tree shapes (open center, small and sparse canopy, and natural roundhead) created by specific training and pruning regimes were all significantly higher than the control (trees not trained or pruned, but left to grow naturally) for all the canopy positions. Relative light intensity followed the same trend, regardless of canopy position (open center shape > small and sparse canopy > natural roundhead shape). The relative light intensity in the outer layer of the open center shape was highest (93.89%), This was 10.34% higher than the value for thesmall and sparse canopy shapes, 23.29% higher than in the natural roundhead shape, and 41.08% higher than the control. These results indicated that C. henryi received more light when it had an open center shape. Diurnally, the net photosynthetic rate (Pn) for C. henryi leaves taken from different shaped trees had two peaks at 10:00 and 14:00. The Pn for leaves on the open center shaped trees (9.97 μmol m-2 s-1) was higher than the values for the other two shapes and the control. 2) Some photosynthetic parameters differed significantly among the tree shapes. The maximum Pn and the light saturation point in trees with the open center shape were higher than the values recorded for the other tree shapes. However, the CO2 compensation point and dark respiration rate for leaves on the open center shaped trees were lower than the values for the other two tree shapes and the control. Additionally, the carboxylation efficiency of the open center shaped trees was significantly higher than it was for the other shapes, all of which indicated that the photosynthetic performance of the open center shape trees was better than the other shapes. 3) The chlorophyll fluorescence parameter results showed that maximum fluorescence (Fm), PS II maximal efficiency (Fv / Fm), PS II potential efficiency (Fv / Fo), and the electron transport rate (ETR) for each of the three tree shapes significantly improved compared to the control. The ETR in the open center shaped trees was higher than the ETR values for the other two tree shapes and the control. 4) There were significant differences (P≤0.01) in Pn , transpiration rate, Fv/ Fo , ETR, chlorophyll content, and yield per plant, and the correlation index between Pn and yield per plant was highest (r = 0.835). Thus, manipulating tree shape by training and pruning can significantly improve the ventilation and light conditions in the inner layer of a tree, improve the utilization ratio of light energy, and increase yield. Based on our results, C. henryi trees with an open center shape are superior in light energy use to the ones with small and sparse canopies and natural roundhead shapes. Therefore training and pruning C. henryi to have an open center shape will improve yields. © 2005, Ecological Society of China. All rights reserved. Source


Wu H.,International Center for Bamboo And Rattan | Lv H.,Hunan Forest Botanical Garden | Li L.,International Center for Bamboo And Rattan | Liu J.,International Center for Bamboo And Rattan | And 3 more authors.
PLoS ONE | Year: 2015

The AP2/ERF transcription factor family, one of the largest families unique to plants, performs a significant role in terms of regulation of growth and development, and responses to biotic and abiotic stresses. Moso bamboo (Phyllostachys edulis) is a fast-growing non-timber forest species with the highest ecological, economic and social values of all bamboos in Asia. The draft genome of moso bamboo and the available genomes of other plants provide great opportunities to research global information on the AP2/ERF family in moso bamboo. In total, 116 AP2/ERF transcription factors were identified in moso bamboo. The phylogeny analyses indicated that the 116 AP2/ERF genes could be divided into three subfamilies: AP2, RAV and ERF; and the ERF subfamily genes were divided into 11 groups. The gene structures, exons/introns and conserved motifs of the PeAP2/ERF genes were analyzed. Analysis of the evolutionary patterns and divergence showed the PeAP2/ERF genes underwent a large-scale event around 15 million years ago (MYA) and the division time of AP2/ERF family genes between rice and moso bamboo was 15-23 MYA. We surveyed the putative promoter regions of the PeDREBsand showed that largely stress-related cis-elements existed in these genes. Further analysis of expression patterns of PeDREBs revealed that the most were strongly induced by drought, low-temperature and/or high salinity stresses in roots and, in contrast, most PeDREB genes had negative functions in leaves under the same respective stresses. In this study there were two main interesting points: there were fewer members of the PeDREB subfamily in moso bamboo than in other plants and there were differences in DREB gene expression profiles between leaves and roots triggered in response to abiotic stress. The information produced from this study may be valuable in overcoming challenges in cultivating moso bamboo. © 2015 Wu et al. Source


Zhu F.,Central South University of forestry and Technology | Zhu F.,State Key Laboratory of Ecological Applied Technology in Forest Area of South China | Hong X.Q.,Central South University of forestry and Technology | Yan W.D.,Central South University of forestry and Technology | And 4 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2014

Polycyclic aromatic hydrocarbons (PAHs) are widespread in nature because of several polluting anthropogenic activities. They have been recognized as a potential health risk due to their intrinsic chemical stability, high recalcitrance to different types of degradation and high toxicity to living organisms. Soil enzymes, being in intimate contact with the soil's environment and very sensitive to any ecosystem perturbation, are well suited for assessing the impact of pollution on the soil quality. The aim of this trial was to quantify the responses of soil enzyme activity during the phytoremediation of PAHs impacted soil. Four tree species including Cinnamomum camphora, Magnolia grandiflora, Koelreuteria bipinnata, Liriodendron chinense, from subtropical China, were selected and planted separately in the pots in which soils were treated with diesel oil to three concentration levels of PAHs(L1 < L2 < L3). Phosphatase, polyphenol oxidase and hydrogen peroxide activity were evaluated at 0, 3, 6, 9 and 12 months after the PAHs contamination. The resulted showed that the inhibition rates of polyphenol oxidase activity ranged from-94.98% to 16.29%, the inhibition rates of hydrogen peroxide activity ranged from-76.71% to 13.19%, and the inhibition rates of phosphatase activity ranged from-49.62% to 56.38%. Enzymatic activity in PAHs contaminated soils were also affected by different tree species. Analysis of variance indicated that there was a significant difference of hydrogen peroxide activity between different PAHs levels and there were a significant difference of 3 enzyme activities between different times, but all 3 enzyme activities were not significant between interactions of different trees and PAHs levels and between interactions of different times and PAHs levels. Two principal components were extracted from the principal component analysis and their cumulative contribution of variance accounted for 94.19%. The variance contribution rate of PC1 and PC2 were 87.61% and 6.58%, respectively. The correlation coefficients between main substrates and PC1 or PC2 indicated that enzymatic activity was influenced by PAHs and trees together, but the such influence from PAHs contamination was higher than that from the trees. Meanwhile, the principal component analysis also showed the polyphenol oxidase and phosphatase activities impacted by the PAHs and trees were higher than the hydrogen peroxide activity. Source


Fan X.,Central South University of forestry and Technology | Yuan D.,Central South University of forestry and Technology | Tang J.,Hunan University of Technology | Tian X.,Hunan Forest Botanical Garden | And 3 more authors.
Trees - Structure and Function | Year: 2015

Key message: We provide new embryological information regarding the Fagaceaefamily. Abortive ovules may be a result of mate choice and be necessary to maximize reproductive success in Chinese chinquapin (Castanea henryi).Abstract: In contrast to most angiosperms, in which fertilization occurs 1–2 days after pollination, fertilization in Fagales is delayed from 4 days to more than 1 year. However, the phenomenon of delayed fertilization in Castanea Miller species (Fagaceae), which are the economically important species of Fagaceae and widely distributed or cultured in many countries of the world, has been consistently neglected, raising questions regarding what the delayed fertilization process is and why fertilization is delayed. To answer these questions, we systematically investigated the micro- and megasporogenesis in addition to male and female gametogenesis in Castanea henryi (Castanea Miller species). Our results show that the ovules primordia are immature at the time of pollination and require 6 weeks to become fully developed. During this 6-week period, 32.30 % of ovules abort because of the inability to form an embryo sac (ES). Approximately 15.79 % of ovules abort because of abnormal development of ES. From 7 to 8 weeks after pollination in which double fertilization occurs, most mature ovules are also aborted because of cell degeneration in gametophytes. Only one ovule can develop into a ripe seed. Thus, the delayed fertilization in Castanea henryi may be necessary to increase the time for mate choice and selective fertilization. A certain number of ovule abortions may be the result of delayed fertilization to maximize reproductive success. © 2015 Springer-Verlag Berlin Heidelberg Source

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