光照处理对冬虫夏草单孢菌株生长代谢的影响     

谢放  苏强军  夏樱霞  李佳莹  陈照禾  周刚 《西北农业学报》2021,(7):1060-1070

为了探究光照处理对中国被毛孢生长代谢的影响,通过分离单子囊孢子获得单孢菌株,并对该菌株进行光照处理。观察记录光照处理30 d后菌落和菌丝形态的变化,测量菌落鲜质量、干质量以及分生孢子量,通过比色法检测甘露醇、多糖、尿素和多酚4种代谢物含量的变化,并通过UPLC检测腺苷含量的变化。结果表明,光照处理后中国被毛孢菌落形态发生显著变化;菌落鲜质量显著低于黑暗处理组,干质量无明显差异;菌丝的延伸被抑制并出现扭结现象;分生孢子数量显著高于黑暗处理组;多糖和尿素含量均显著低于黑暗处理组;甘露醇和多酚含量无显著变化;腺苷含量显著高于黑暗处理组。  相似文献   

温度、盐度和光照对海蜇足囊繁殖的影响   总被引：7，自引：1，他引：7  

鲁男  蒋双  陈介康 《水产科学》1997,(1)

在实验室条件下，就温度、盐度和光照对海蜇（Ｒｈｏｐｉｌｅｍａｅｓｃｕｌｅｎｔａｋｉｓｈｉｎｏｕｙｅ）足囊形成和萌发的影响进行观察。温度实验在０～３０℃范围内设７组，盐度实验在２～３２．１‰范围内设１６个梯度，光照分为自然光和黑暗两组。实验显示：１０℃以上海蜇无足囊繁殖迹象，１５～３０℃范围内，随温度升高，海蜇足囊繁殖能力增强；６‰以下盐度，海蜇不能进行足囊繁殖，２０～２２‰是海蜇足囊繁殖的最适盐度；黑暗有利于足囊繁殖。温度是足囊繁殖的关键因子，盐度和光照是足囊繁殖的充分条件。作者认为，适宜的环境因子是海蜇螅状体形成的必要条件，尽管足囊可以抵御外界的恶劣环境，但足囊形成并非需要不良环境因子诱导，足囊繁殖是海蜇螅状体一种正常的无性繁殖方式  相似文献   

Using a stand-level model to predict light absorption in stands with vertically and horizontally heterogeneous canopies     

David I Forrester  Rubén Guisasola  Xiaolu Tang  Axel T Albrecht  Tran Lam Dong  Guerric Ie Maire 《中国林学(英文版)》2014,1(3):158-176

Background： Forest ecosystem functioning is strongly influenced by the absorption of photosynthetically active radiation （APAR）, and therefore, accurate predictions of APAR are critical for many process-based forest growth models. The Lambert-Beer law can be applied to estimate APAR for simple homogeneous canopies composed of one layer, one species, and no canopy gaps. However, the vertical and horizontal structure of forest canopies is rarely homogeneous. Detailed tree-level models can account for this heterogeneity but these often have high input and computational demands and work on finer temporal and spatial resolutions than required by stand-level growth models. The aim of this study was to test a stand-level light absorption model that can estimate APAR by individual species in mixed-species and multi-layered stands with any degree of canopy openness including open-grown trees to closed canopies. Methods： The stand-level model was compared with a detailed tree-level model that has already been tested in mixed-species stands using empirical data. Both models were parameterised for five different forests, including a wide range of species compositions, species proportions, stand densities, crown architectures and canopy structures. Results： The stand-level model performed well in all stands except in the stand where extinction coefficients were unusually variable and it appears unlikely that APAR could be predicted in such stands using （tree- or stand-level） models that do not allow individuals of a given species to have different extinction coefficients, leaf-area density or analogous parameters. Conclusion： This model is parameterised with species-specific information about extinction coefficients and mean crown length, diameter, height and leaf area. It could be used to examine light dynamics in complex canopies and in stand-level growth models.  相似文献   

光照强度对巴西橡胶树淡绿期叶片光合特性和活性氧代谢的影响     

王立丰  陆艳茜  邓玉杰 《热带作物学报》2014,35(6):1131-1136

橡胶树种苗培育过程中需要避免强光照射,但光照强度对橡胶树幼苗叶片生理活性的作用机制尚不清楚。以橡胶树品系GT1的实生苗为材料,对植株进行不同光照强度处理,测定其淡绿期叶片在不同光照强度下的光合特性和活性氧代谢情况。结果表明,随着光照强度的增加,橡胶树淡绿期叶片的光化学效率(Fv/Fm)呈现上升规律,同时过氧化物的含量也呈现上升趋势,但是由于抗氧化酶对活性氧清除的作用,1 000μmol/m2·s的高光照强度并没有对橡胶树叶片造成伤害。说明200~400μmol/(m2·s)的光照强度比较适合橡胶树苗淡绿期叶片的生长和发育。  相似文献   

光照对香菇菌丝后熟转色过程中活性氧代谢及自噬的影响     

管婉  储婷  鲍大鹏  黄天宇  张建  黄卫华  李福后  唐利华 《核农学报》2022,36(9):1834-1840

为研究光照对香菇菌丝后熟转色过程中活性氧代谢的影响,通过设置自然光照条件与黑暗条件下香菇菌丝后熟转色对比试验,分析其活性氧含量、丙二醛(MDA)含量、还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶活性、抗氧化酶活性及自噬的差异。结果表明,自然光照条件下香菇菌丝正常后熟转色,黑暗条件下香菇菌丝不转色。自然光照条件下香菇菌丝活性氧含量、MDA含量、NADPH氧化酶活性、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性均显著高于黑暗条件,超氧化物歧化酶(SOD)活性变化则与之相反。同时,香菇菌丝细胞自噬的透射电镜分析及实时荧光定量PCR(qRT-PCR)对自噬基因Atg8的表达水平分析结果表明,在自然光照条件下香菇菌丝细胞的自噬特征明显。本研究结果为优化香菇栽培的环境条件提供了一定的理论依据,也为后续对光照环境下香菇体内氧化平衡的作用机理研究提供了有效参考。  相似文献   

VSC-HVDC输电系统的特点与应用     

唐博  王鹏 《农业机械化与电气化》2014,(1):47-49

轻型直流输电系统是基于VSC技术的新型直流输电技术。介绍轻型直流输电基本原理,对比轻型直流输电技术与传统直流输电技术在结构和功能方面的区别,阐述轻型直流输电的优点,并对其应用进行总结和展望,以期为轻型直流输电技术在我国的应用和发展提供一定参考。  相似文献   

MODIS数据在森林火点识别中的应用研究     

段卫虎  黄诚  王皓  周汝良 《安徽农业科学》2014,(28):9800-9803

以昆明市安宁县和玉溪市易门县为研究区,选用MODIS数据作为数据源,ARCGIS和ENVI软件作为数据处理平台,采用绝对亮温、相对亮温和植被指数3个因子作为林火判断条件,提高林火判别的精度,为森林火灾的早期探测与发现、火灾扑救和损失评估业务在云南省的运用奠定基础.  相似文献   

樟树光合特性的季节动态     

罗辅燕  陈卫英 《东北林业大学学报》2014,(9)

樟树（ Cinnamonum campora）春、夏、秋季净光合速率日动态均呈现“双峰型”曲线,而冬季为“单峰型”曲线,其日最大净光合速率和日均值存在明显的季节变化,由大到小的排序均为夏季（9．06、7．03μmol· m-2· s-1）、秋季（7．23、5．96μmol· m-2· s-1）、春季（6．91、5．58μmol· m-2· s-1）、冬季（5．60、4．32μmol· m-2· s-1）。基于指数改进模型估算的樟树不同季节光合参数分析得出,樟树光补偿点、光饱和点、最大净光合速率、暗呼吸速率均呈现显著的季节变化,夏季樟树光补偿点（63．44μmol· m-2· s-1）最大,春、秋、冬季（均约为52．3μmol· m-2· s-1）没有显著差异;夏季的光饱和点（1625．70μmol· m-2· s-1）、最大净光合速率（9．19μmol· m-2· s-1）最大,春季（1519．39、6．80μmol· m-2· s-1）和秋季（1509．53、7．71μmol· m-2· s-1）两者没有显著差异,冬季最小（1267．31、5．31μmol· m-2· s-1）;樟树夏季暗呼吸速率（2．53μmol· m-2· s-1）最大,春、秋、冬季（均约为1．4μmol· m-2· s-1）没有显著差异。可见,樟树为强阳性树种,一年四季均具有较好的净光合速率和生长潜力。  相似文献   

大棚栽培葡萄构成高产质优因素的分析     

左建英  李占贵 《内蒙古农业科技》2014,(3):46-46

设施农业的快速发展,推动了高寒地区种植业的多样化.葡萄产业由于品种繁多,产业链长,市场效益高,发展尤为突出,通过调查大同地区的几个县区葡萄大棚栽培模式分析构成质优高产的综合因素,总结出大棚栽培葡萄的优势.  相似文献   

The effects of light and temperature on the photosynthesis of the Asparagopsis armata tetrasporophyte (Falkenbergia rufolanosa), cultivated in tanks     

Leonardo Mata  João Silva  Andreas Schuenhoff  Rui Santos 《Aquaculture (Amsterdam, Netherlands)》2006,252(1):12-19

The integrated aquaculture of the tetrasporophyte of Asparagopsis armata Harvey (Falkenbergia rufolanosa) using fish farm effluents may be viable due to the species high capacity of removing nutrients and its content of halogenated organic compounds with applications on the pharmaceutical and chemical industries. In order to optimize the integrated aquaculture of F. rufolanosa, we followed the daily variation of the potential quantum yield (F_v/F_m) of PSII on plants cultivated at different biomass densities and different total ammonia nitrogen (TAN) fluxes to check if they are photoinhibited at any time of the day. Moreover, the photoinhibition under continuous exposure to highly saturating irradiance and its potential for subsequent recovery in the shade was assessed. The potential for year round cultivation was evaluated by measuring rates of O₂ evolution of plants acclimated at temperatures ranging from 15 to 29 °C, the temperature range of a fish farm effluent in southern Portugal where an integrated aquaculture system of F. rufolanosa was constructed.Photoinhibition does not seem to be a major constrain for the integrated aquaculture of F. rufolanosa. Only when cultivated at a very low density of 1.5 g fresh weight (FW) l^− 1 that there was a midday decrease in maximal quantum yield (F_v/F_m). At densities higher than 4 g FW l^− 1, no photoinhibition was observed. When exposed to full solar irradiance for 1 h, F. rufolanosa showed a 33% decrease in F_v/F_m, recovering to 86% of the initial value after 2 h in the shade. A midday decline of the F. rufolanosa F_v/F_m was also observed under the lowest TAN flux tested (∼6 μM h^− 1), suggesting that this fast and easy measurement of fluorescence may be used as a convenient diagnostic tool to detect nutrient-starved unbalance conditions of the cultures. Maximum net photosynthesis peaked at 15 °C with 9.7 mg O₂ g dry weight (DW)^− 1 h^− 1 and remained high until 24 °C. At 29 °C, the net oxygen production was significantly reduced due to a dramatic increase of respiration, suggesting this to be the species' lethal temperature threshold.Results indicate that F. rufolanosa has a considerable photosynthetic plasticity and confirm it as a good candidate for integrated aquaculture at temperatures up to 24° C and cultivation densities of at least 5 g FW l^− 1. When cultivated at these densities, light does not penetrate below the first few centimetres of the surface zone. Plants circulate within the tanks, spending around 10% of the time in the first few centimetres where they are able to use efficiently the saturating light levels without damaging their photosynthetic apparatus.  相似文献