Effects of vegetation history on distribution of Al in surface soils of suburban forests in Aichi Prefecture, Japan     

Min Sik Kim  Chisato Takenaka  Ho Taek Park 《Journal of Forest Research》2006,11(5):365-368

This study examined the distribution of water-extractable Al in soils from forest sites near Nagoya in Aichi Prefecture. The mean concentrations of water-extractable Al in surface soils varied markedly among sites, with the values at site FGB (126 mg/kg) higher than those at sites FG (11.8 mg/kg) and FCB (33.8 mg/kg). Comparisons of the acid buffer capacity of vegetation at the sites revealed that forest cover has a higher capacity for neutralization than the denuded state. We found that the effects of acidic accumulation in the surface soils of suburban forests might depend on vegetation history, and that forest soils that once had no vegetation cover accumulated labile Al due to acidification. The phenomenon was particularly distinct on granite bedrock.  相似文献   

Optimum timing of gibberellin A4/7 sprays to promote cone production in jack pine seedlings     

Rong H. Ho  Oldrich Hak 《New Forests》1994,8(1):61-69

Three-year-old jack pine (Pinus banksiana Lamb.) seedlings in pots were sprayed with gibberellin A_4/7 solution during the 1989 growing season. Unsprayed and sprayed controls, and seedlings sprayed with gibberellin A_4/7 at three concentrations (200, 400 and 600 mgL^-1) were tested in each of five different treatment periods based on jack pine morphogenesis. Each spraying period consisted of five weekly applications between May and October. Trees produced significantly more pollen cones than the two controls when sprayed at 400 or 600 mgL^-1 during July and early August. Spraying at 600 mgL^-1 during May–June and June–July produced significantly more seed cones than the two controls, as did spraying at 400 or 600 mgL^-1 during July and early August. The best treatment for both pollen- and seed-cone production was weekly spraying at 400 or 600 mgL^-1 gibberellin A_4/7 from early July, which coincided with the end of terminal shoot elongation, through early August, which coincided with microsporophyll initiation in the pollen-cone buds and initiation of the potential seed-cone buds.  相似文献   

Promotion of cone production in potted black-spruce grafts, using gibberellins, heat-treatment and root-pruning     

Rong H. Ho 《Forest Ecology and Management》1991,40(3-4):261-269

Potted 3-year-old grafts of black spruce [Picea mariana (Mill.) B.S.P.] at different stages of lateral shoot elongation were sprayed with different concentrations of gibberellin A_4/7 for a total of six weeks in a heated greenhouse to enhance seed-cone production. Grafts sprayed during the period of lateral shoot elongation produced significantly more seed cones but not pollen cones, while spraying initiated after the elongation did not promote any cone production. Increasing gibberellin did not increase production, but increased graft mortality when spraying was done during the period of rapid shoot elongation. Cone production was highest and mortality lowest with 200 mg l⁻¹ gibberellin A_4/7 spraying that was initiated in the middle of rapid shoot elongation. In a second experiment, potted 5-year-old grafts with or without root pruning were placed either outdoors or in a heated greenhouse during the period of lateral shoot elongation. Heat-treatment during the period of late show shoot elongation had a positive effect on pollen- and seed-cone production in 5-year-old grafts without root-pruning. A combination of heat-treatment and root-pruning appeared to have an adverse effect on cone production. Pollen viability was not affected by the treatments.  相似文献   

西双版纳民间常作食用的野生药、蔬两用植物     

朱涛  彭朝忠  管志斌  鄢姗 《热带农业科技》2002,25(2):31-33

介绍西双版纳民间常作食用的种野生药蔬两用植物,主要药用功效、食用部位和食用方法。  相似文献   

中国豆粕市场的价格博弈分析   总被引：1，自引：0，他引：1  

刘亚相  王征兵  刘欠宁  单青松  昝林森 《中国农学通报》2005,21(12):17-17

分析了豆粕价格波动现状及对饲料行业和畜牧业的不利影响，构造了n个博弈方的伯特兰德（Bertrand）价格博弈模型，通过求解方程组得出以下结论：异质产品的Bertrand博弈只有一个均衡。对2人情形，得出了均衡对称条件下的市场价格。  相似文献   

油菜秸秆适宜发酵条件研究   总被引：2，自引：0，他引：2  

汪季涛  朱世东  胡克玲  王健  单国雷  张村侠  赵冠艳 《中国农学通报》2006,22(12):373-373

笔者采用正交设计的方法研究了油菜秸秆的粒径长度、C/N比、含水量、氮源对油菜秸秆堆肥发酵的性能参数，包括堆肥温度、C/N比、秸秆发酵后的浸提液种子发芽指数等的影响。结果表明：秸秆长度、氮源和含水量对油菜秸秆堆肥发酵效果的影响显著，而在本试验所设置的C/N比值范围内，C/N比对油菜秸秆堆肥发酵效果的影响不显著。综合各项指标以及从能耗和成本角度考虑，确定油菜秸秆发酵宜采用粒径长度为5cm，C/N比值为25，含水量为70%，氮源为鸡粪的组合进行堆肥发酵。  相似文献   

Direct Alloying of High Speed Steel M2 with CaWO_4 MoO_3 V_2O_5     

JIANG Han xiang  YU Chen long  SUN Shan chang  ZHEN Tiao 《保鲜与加工》2002,(5):76-79

The principle and possibility of alloying of high speed steel W6Mo5Cr4V2 (M2) with CaWO 4 MoO 3 V 2O 5 during the steelmaking are discussed, experiments of the alloying technologcial process have been carried out, the properties of M2 product have been determined, the benefit have been analysed. The results show that the rate of recovery of W Mo V are respectively 97.08%, 96.51%, 93.79% during the steelmaking of M2 alloying with CaWO 4 MoO 3 V 2O 5 in induction furnace, the chemical composition and properties of product M2 can meet the demands that the standard of high speed steel M2 requires.  相似文献   

Azide Method Applied in the Synthesis of Antineoplastic Active Meterials-N''-Phenyacetyl-N-Substituted Glutamine     

LI Qin geng  LUO Yong peng  CHEN Jie  JI Qing gang  YANG Shan bin  JIN Chu rong 《保鲜与加工》2002,(5):157-160

The results of studies of Antineopalston A10 show it's degradation products, such as glutamines and isoglutamines, having antitumor activity. According to these, some N'-phenylacetyl-N-substituted glutamines are designed and synthesized for researching their antitumor activity. In the syntheses of these compounds, the acid azides are prepared first, which then react with amines at low temperature to transform to the target molecules. The mild reaction conditions and good yields and the optical activity maintaining are the merits of this method. Evaluation of antitumor activity of the target molecules is carried out by MTT method to L1210 cell strain. The result showes some compounds can inhibit growth of the cancer cells.  相似文献   

不同基因型大麦离体培养的花药及小孢子对低温和NaCl预处理的反应     

孙月芳  陆瑞菊  王亦菲  单丽丽  黄剑华 《中国农学通报》2007,23(4):46-46

以探讨大麦单倍体细胞水平的耐冷、耐NaCl性与植株水平抗病、耐盐性的相关性为目的，用赤霉病抗性、耐盐性不同的大麦为供试材料，比较了它们的离体培养花药及小孢子对低温、NaCl预处理的培养反应。结果表明：感病材料低温（5℃）预处理17d的花药培养愈伤组织诱导率比未经低温预处理的低，抗病材料则有一定的升幅。用NaCl溶液直接处理游离小孢子，所有供试材料的小孢子存活率随处理浓度升高不断下降，耐盐材料的存活率下降幅度比盐敏材料的小，且抗病材料的降幅比感病材料的小。说明：供体植株水平的抗病、耐盐性在花药、小孢子水平上也能有所表现。  相似文献   

发酵法生产超氧化物歧化酶的研究进展   总被引：1，自引：0，他引：1  

陈珊  张乐 《农产品加工．学刊》2015,(6)

超氧化物歧化酶是一类广泛存在于生物体中的金属酶,在医药、食品和化妆品领域有较广泛的应用.通过介绍菌种选育、培养条件优化以及分离纯化方法,以提供该方面的研究新进展.  相似文献