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101.
102.
Lin Shanzhi Zhang Zhiyi Lin Yuanzhen Liu Wenfeng Guo Huan Zhang Wei Zhang Chong 《中国林学(英文版)》2004,6(3):1-8
To explore the physiological and biochemical mechanism of the occurrence of vitrified shoots of Populus suaveolens in tissue culture, the changes in water, chlorphyll, lignin, H2O2, phenylalanine ammonialyase (PAL), malonaldehyde (MDA), protective enzymatic systems, and some key enzymes involved in the
ascorbate- glutathione cycle were comparatively studied in both normal and vitrified shoots of P. suaveolens. The results show that the lower activities of peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate
reductase (DHAR), glutathione reductase (GR) and PAL, and the less contents of chlorphyll, lignin, ascorbate (ASA) and reduced
glutathione (GSH) as well as the lower ratios of ASA / DHA and GSH / GSSG are observed in vitrified shoots than in normal
ones during the whole culture period. While in comparison with normal shoots, the higher activity of superoxide dismutase
(SOD) and the more concentrations of water, H2O2, MDA, dehydroascorbate (DHA) and oxidized glutathione (GSSG) are found in vitrified shoots. Statistical analysis indicates
that the enhanced activity of SOD and the decreased activities of CAT and POD as well as some enzymes involved in the ascorbate-glutathione
cycle might be closely correlated to the accumulation of H2O2. The less regeneration of ASA and GSH and the lower capacity of the ascorbate-glutathione cycle observed in vitrified shoots
might be due to a significant decrease in APX, MDAR, DHAR and GR activities and a decline in redox status of ASA and GSH.
The decreases in chlorphyll content might result in a decline in photosynthesis. The lower activities of POD and PAL could
result in the decrease of lignin synthesis and cell wall ligination, which might be the key factor leading to the increase
in water content. It is concluded that the deficiency of detoxification capacity caused by the lower capacity of the ascorbate-glutathione
pathway and the decreased activity of protective enzymatic system might lead to the large accumulation of H2O2 and the enhancement of membrane lipid peroxidation, which might be the main cause leading to the occurrence of vitrifying
shoots of P. suaveolens in tissue culture.
[Supported by National Natural Science Foundation of China (Grant No. 30271093) and the Foundation of State-designated Base
for Biology Researching and Teaching in Beijing Forestry University] 相似文献
103.
三倍体毛白杨无性系木材两个切面密度的可视化 总被引:4,自引:0,他引:4
This study uses two different mathematical models and gets two dimensional graphs of longitudinal and tangential section wood density at the same time by the radial wood density data measured by X-ray. The graph is direct and clear. It can be used to analyze the distribution and difference of wood density. It can also be done various kinds of transformation, including different angle, different colors, space and plane, part and entirety. This develops the visible analysis of wood density. Next the distribution of wood density of veneer will be simulated by new mathematical model and radial wood density data. 相似文献
104.
毛白杨,河北杨多代循环繁殖方法的研究 总被引:3,自引:1,他引:3
从1983年起,对毛白杨、河北杨的扦插繁殖育苗及其机理进行了研究,研究出“多代循环繁殖新方法”,无需任何处理,也无需地膜覆盖,使大田育苗成活率稳定在80%左右;同时研究出快速、简便、繁殖系数高的优树根萌条培育新技术,为毛白杨、河北杨优树的无性系测定、无性系育种和无性系造林创造了条件。 相似文献
105.
在人工接种和自然感虫情况下美洲黑杨后代对桑天牛抗性的研究 总被引:5,自引:0,他引:5
杨树 (Populusspp .)是我国主要造林和工业用材树种之一 ,据统计我国杨树人工林面积达 666×1 0 4hm2 (王世绩 ,1 995 )。但杨树天牛危害十分猖獗 ,其中光肩星天牛 (Anoplophoraglabripennis)和黄斑星天牛 (Anoplophoranobi 相似文献
106.
在低温锻炼中毛白杨幼苗可溶性总蛋白、RNA、DNA、RNase及抗冻性的变化 总被引:4,自引:0,他引:4
低温锻炼不仅提高了毛白杨幼苗存活率和抗冻性以及RNA和可溶性总蛋白的含量 ,降低了RNase活性 ,而且能减轻低温胁迫引起的RNA和可溶性总蛋白含量的下降程度和RNase活性的提高 ,有利于幼苗在恢复过程中RNA和可溶性总蛋白水平的迅速回升以及RNase活性的降低 .进一步研究发现 ,DNA含量无论在低温锻炼中还是在低温胁迫下或是在随后的恢复生长期均保持相对稳定 ;低温锻炼所引起的RNA含量的增加 ,与RNase活性的降低呈明显的负相关 ,与可溶性总蛋白含量的增加以及幼苗抗冻性的提高成正相关 .这表明低温锻炼可能抑制RNase活性 ,有效地促进RNA含量的增加 ,而RNA可能参与了可溶性总蛋白的合成及抗冻性的诱导 相似文献
107.
DUAN Xinfang BAO FuchengResearch Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2004,3(4):59-64
In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tomentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures, and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6~0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese white poplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation. 相似文献
108.
收集我国东北林区特有乡土树种大青杨天然基因资源400多份。在黑龙江省伊春带岭建立了我国第一个大青杨基因库,利用常规手段对其生长,物候,抗锈病和木材材性等性状进行了遗传分析,利用高新技术方法从DNA分子水平上探测了大青杨天然群体的遗传结构和分化程度,经综合评价选出5个优良群体,44个优良单株,为该地区营建大青杨人工林奠定了一定基础,为杨树抗性育种等提供了育种材料和信息,认为选择优良个体是近期大青杨改良的一条重要途径。 相似文献
109.
YU Huaqiang ZHAO Rongjun FU Feng FEI Benhua JIANG Zehui Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2007,6(2):14-19
The visible and near infrared (NIR) (350-2500 nm) spectra and the MOE of 438 small clear wood samples from Chinese fir, eucalyptus and poplar 72 were measured. Using partial least-square (PLS) modeling, the NIR spectra could be used to predict MOE and MOR of the clear-wood samples from Chinese fir and eucalyptus solid wood. NIR spectra could only be used to Predict MOE but not MOR of poplar clear-wood samples. With the exception of MoR of poplar clear-wood samples, the correlations between NIR and the mechanical properties are very strong, and the calibration and test correlation coefficients are both above 0.80. 相似文献
110.
XU Ming REN Haiqing LI Xiazhen 《中国林业科技(英文版)》2007,6(3):40-44
The variation of tensile strength parallel to grain in Chinese fir and 1-214 poplar wood from plantations was studied in this paper. Aaccording to the national standards The Testing Methods for Physical and Mechanical Properties of Wood (GB 1927 to 1943 -- 1991), the small clear wood samples were cut and tested, which represent the south and north of trees with heights of 1.3, 3.3, 5.3 and 7.3 m. The results showed: the tensile strength parallel to grain of the north wood was higher than that of south wood. ANOVA shows that the tensile strength parallel to the grain with height is of significant difference (at 0.05 level). 相似文献