Comparative study on antioxidative system in normal and vitrified shoots of Populus suaveolens in tissue culture     

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   

云南松花粉精粉及其加工产品的成分分析及评价     

范国栋  刘嘉宝  冯武 《西部林业科学》2002,(3):86-89

对以云南松破壁松花粉为原料 ,采用具创新性生物技术研制的云南松花粉脂提物精粉、活性酶精粉、黄酮精粉、营养及活性物质精粉 ,以及用此 4种精粉经加工而获得的亚油酸软胶囊、口服 0 #胶囊、黄酮药片 (胶囊 )、精粉口服液和松花粉酮酒 5种产品的成分进行了分析 ,了解到它们相关成分的含量。分析结果表明 ,4种云南松花粉精粉具有速溶性好、营养及生物活性物质集中的特点 ,其主要营养及生物活性物质含量数倍于破壁松花粉。以其为原料加工的各项产品很好地保留了精粉的主要功能成分 ,因而对人体具有更高的保健、医疗功效。  相似文献   

Carbon return and dynamics of litterfall in natural forest and monoculture plantation of Castanopsis kawakamii in subtropical China     

Guo Jianfen  Xie Jinsheng  Lu Haoliang  Liu Dongxia  Yang Yusheng  Chen Guangshui 《中国林学(英文版)》2004,6(1):33-36

The amount of carbon returned through litterfall and its seasonal pattern were studied in a natural forest of Castanopsis kawakamii (NF) and adjacent monoculture plantations of C. kawakamii (CK) and Chinese fir (Cunninghamia lanceolata) (CF) in Sanming, Fujian Province, China. Mean annual carbon return through total litterfall over 3 years (from 1999 to 2001) was 5.097 t·hm⁻² in the NF, 4.337 t·hm⁻² in the CK and 2.502 t·hm⁻² in the CF respectively. Of the total carbon return in the three forests, leaf contribution accounted for 58.96%, 68.53% and 56.12% and twig 24.41%, 22.34% and 26.18%, respectively. The seasonal patterns of carbon return from total litterfall and leaf-litter were quite similar among the three forests. A peak of carbon input from litterfall in the NF and the CK occurred in spring except for the highest annual C return through branch litter of the NF in summer, while the CF showed the maximum C return in summer. The results of this study demonstrate that the natural forest has a greater C return through litterfall than monoculture plantations, which is beneficial to the increase of soil organic matter storage and the maintenance of soil fertility. [Supported by the Teaching and Research Award Program of MOE P.R.C. (TRAPOYT) and the Key Basic Research Project of Fujian Province (2000F004)]  相似文献   

温度对大叶桃花心木(Swietenia macrophylla King)幼苗叶片的光合影响   总被引：2，自引：0，他引：2  

张成军  祖元刚  郭佳秋 《林业研究》2003,14(2):130-134

本文研究了大叶桃花心木（Swietenia macrophylla King）一年生幼苗在经过夜温处理后的光响应曲线和在饱和光强下的CO2反应曲线.结果表明:在大气CO2浓度下,叶片的最佳光合作用温度在25-31℃之间,而在饱和CO2浓度下为31-35℃.在25℃以下光合速率开始降低,主要是由于羧化效率的降低,而当温度超过31℃时,光合速率下降,是因为羧化效率的降低和呼吸速率的增加.CO2浓度对光合的促进作用在低温下受到抑制,这意味着未来在CO2浓度增高的情况下,高浓度的CO2对热带常绿植物光合的促进在冬天低温情况下表现不十分明显.图4参23.  相似文献   

高温水供热干燥速生杉木方材     

涂登云  顾炼百  杜国兴 《木材工业》2001,15(5):31-32,34

运用高温水供热系统干燥速生杉木方材。生产性试验表明，6天内初含水率为55．5％的杉木方材干至始含水率5．4％，干燥质量符合细木工板生产的要求（少数高含水率木材除外）。此干燥法集中供热，具有热效率高、运行安全和经济可行等特点。  相似文献   

如皋市双条杉天牛的发生及综合防治   总被引：3，自引：0，他引：3  

沈继珍  高国兴  丁海琴  陈建华  许小林 《江苏林业科技》2001,28(4):34-36

对双条杉天牛从形态特征、生物学特性、寄主范围、危害率等方面进行了调查，并提出了防治双条杉天牛的对策和措施。  相似文献   

沙柳的材性对刨花板生产工艺的影响   总被引：1，自引：2，他引：1  

高志悦  郭爱龙 《林产工业》1997,(5)

论述了沙柳的材性对刨花板生产工艺和产品质量的影响，并根据分析结果讨论了目前沙柳刨花板的生产工艺，测试了沙柳刨花板的物理力学性能，针对测试结果提出了改善刨花极性能的措施。  相似文献   

A set of primers for analyzing chloroplast DNA diversity in Citrus and related genera   总被引：4，自引：0，他引：4  

Cheng Y  de Vicente MC  Meng H  Guo W  Tao N  Deng X 《Tree physiology》2005,25(6):661-672

Chloroplast simple sequence repeat (cpSSR) markers in Citrus were developed and used to analyze chloroplast diversity of Citrus and closely related genera. Fourteen cpSSR primer pairs from the chloroplast genomes of tobacco (Nicotiana tabacum L.) and Arabidopsis were found useful for analyzing the Citrus chloroplast genome (cpDNA) and recoded with the prefix SPCC (SSR Primers for Citrus Chloroplast). Eleven of the 14 primer pairs revealed some degree of polymorphism among 34 genotypes of Citrus, Fortunella, Poncirus and some of their hybrids, with polymorphism information content (PIC) values ranging from 0.057 to 0.732, and 18 haplotypes were identified. The cpSSR data were analyzed with NTSYS-pc software, and the genetic relationships suggested by the unweighted pair group method based on arithmetic means (UPGMA) dendrogram were congruent with previous taxonomic investigations: the results showed that all samples fell into seven major clusters, i.e., Citrus medica L., Poncirus, Fortunella, C. ichangensis Blanco, C. reticulata Swingle, C. aurantifolia (Christm.) Swingle and C. grandis (L.) Osbeck. The results of previous studies combined with our cpSSR analyses revealed that: (1) Calamondin (C. madurensis Swingle) is the result of hybridization between kumquat (Fortunella) and mandarin (C. reticulata), where kumquat acted as the female parent; (2) Ichang papeda (C. ichangensis) has a unique taxonomic status; and (3) although Bendiguangju mandarin (C. reticulata) and Satsuma mandarin (C. reticulata) are similar in fruit shape and leaf morphology, they have different maternal parents. Bendiguangju mandarin has the same cytoplasm as sweet orange (C. sinensis), whereas Satsuma mandarin has the cytoplasm of C. reticulata. Seventeen PCR products from SPCC1 and 21 from SPCC11 were cloned and sequenced. The results revealed that mononucleotide repeats as well as insertions and deletions of small segments of DNA were associated with SPCC1 polymorphism, whereas polymorphism generated by SPCC11 was essentially due to the variation in length of the mononucleotide repeats.  相似文献   

Effects of density and resin content on the physical and mechanical properties of scrimber manufactured from mulberry branches     

Hai-Xia?Yu  Chong-Rong?Fang  Man-Ping?Xu  Fei-Yan?Guo  Wen-Ji?YuEmail author 《Journal of Wood Science》2015,61(2):159-164

The silk industry in China produces a large amount of mulberry branches as by-product every year. Mulberry branches have high longitudinal toughness and good overall mechanical properties. However, these branches are incinerated because their utility in other industries is limited by their small size. This study determines the feasibility of manufacturing scrimber from mulberry branches by using cold pressing method, followed by thermo-curing with different densities and resin contents. Results show that density [ranging from (0.81–1.24) g/cm³] exerts a greater effect on the shear strength, modulus of rupture (MOR), and modulus of elasticity (MOE) than resin content (changing from 8 to 20 %). The increase rate slows down when the density exceeds 1.1 g/cm³ and the resin content reaches more than 12 %. The strength-to-weight ratio analysis shows that the MOR/density and MOE/density maximum at 1.02–1.10 g/cm³. The density and resin contents of mulberry scrimber with cold compress and heat setting can be set to 1.0–1.1 g/cm³ and at approximately 12 %, respectively. The mechanical properties of the product meet the maximum requirement indicated in the Chinese national standard for construction. Mulberry scrimber can be a very promising supplement for wood because of its good performance, abundant supply, and renewability.  相似文献   

Ecological Benefit of Reforestation in a Severely Degraded Red Soil Region     

Yuanqiu Liu  Guoping Yang  Tianzhen Du  Xiaomin Guo 《Frontiers of Forestry in China》2006,1(1):113-117

Guifeng, Yiyang County, belongs to a seriously degraded red soil region. In 1991, Pinus elliottii and Lespedaza spp. were the species selected for the establishment of a mixed forest in the area. The results of an investigation of the soil system in a 12-year-old forest indicated the following: (1) Organic matter and total nitrogen of the forest soil to a depth of 40 cm were 88.0 and 36.0% higher, respectively, than those of a control plot; total phosphorus and available phosphorus were 40.9 and 22.3% higher than those of the control; available potassium contents were 8.13% lower than those of the control. (2) Soil aeration and the soil air regime improved. (3) Proteinase, catalase, and urease in the forest soil to a depth of 40 cm were usually higher than those in the control plot and decreased with soil depth. Translated from Acta Agriculturae Universitatis Jiangxiensis, 2005, 27(1) (in Chinese)  相似文献