汕头南澳岛沿岸浮游植物对阳光紫外辐射响应的研究

为了阐明汕头南澳岛沿岸表层水体浮游植物群落对阳光紫外辐射(UVR,280～400nm)变化的响应,试验检测了浮游植物在全波段阳光和滤除UVR或UV-B条件下的光合固酸随光强的变化关系,同时还检测了浮游植物群落的紫外辐射作用光谱(BWF).结果表明,阳光UVR可以明显的抑制浮游植物的光合固碳,当滤除UVR后,光合固碳受到的抑制程度下降.在100％阳光辐射条件下,光合固碳受到的抑制程度最大.紫外辐射作用光谱显示,浮游植物对UV-B最敏感,其抑制程度显著大于UV-A波段.     

2种微藻间的化感作用

[目的]研究球等鞭金藻和纤细角毛藻间的化感作用。[方法]利用交叉培养和添加胞外滤液萃取物2种方法,确定2种微藻间的化感作用。最后,通过气相色谱测定两种微藻细胞及胞外滤液萃取物中脂肪酸的组成。[结果]球等鞭金藻滤液对纤细角毛藻的生长有显著的促进作用,仅当滤液浓度为100%时表现抑制作用。纤细角毛藻滤液对球等鞭金藻的生长有显著的抑制作用,滤液浓度越高,抑制作用越强。球等鞭金藻(或纤细角毛藻)胞外滤液萃取物对纤细角毛藻(或球等鞭金藻)生长的影响近似于其胞外滤液对纤细角毛藻(或球等鞭金藻)生长的影响,这暗示着2种微藻培养液中的化感物质可以用有机溶剂进行提取。[结论]通过气相色谱分析,笔者认为球等鞭金藻对纤细角毛藻的化感作用主要由饱和脂肪酸和不饱和脂肪酸的混合物共同作用引起;而纤细角毛藻对球等鞭金藻的化感作用主要由饱和脂肪酸引起。     

离心·冷藏对牟氏角毛藻再培养的影响

[目的]探索牟氏角毛藻经浓缩运输和冷藏保存后再作藻种和饵料的可行性效果。[方法]通过离心和低温冷藏2种方法处理牟氏角毛藻,然后再继续进行再培养,以此来延长牟氏角毛藻的储存时间并减小运输量。[结果]试验表明,经不同离心速度和不同离心时间处理后的角毛藻进行再培养,生长速率不同。在3000r／min的转速下离心7min的角毛藻再培养效果最好,最大生长率可达0．83,并且在此离心条件下的藻泥静置5d之内再添加培养基进行培养仍生长良好。但是经4℃冷藏后的角毛藻常温下再培养效果不好。[结论]低温冷藏会影响藻细胞的正常生长,而且随着冷藏时间的延长,细胞再培养愈来愈困难。因此,建议科研及生产中不采用此种方法作为保种技术。     

离心·冷藏对牟氏角毛藻再培养的影响

[目的]探索牟氏角毛藻经浓缩运输和冷藏保存后再作藻种和饵料的可行性效果。[方法]通过离心和低温冷藏2种方法处理牟氏角毛藻,然后再继续进行再培养,以此来延长牟氏角毛藻的储存时间并减小运输量。[结果]试验表明,经不同离心速度和不同离心时间处理后的角毛藻进行再培养,生长速率不同。在3000 r/min的转速下离心7 min的角毛藻再培养效果最好,最大生长率可达0.83,并且在此离心条件下的藻泥静置5 d之内再添加培养基进行培养仍生长良好。但是经4℃冷藏后的角毛藻常温下再培养效果不好。[结论]低温冷藏会影响藻细胞的正常生长,而且随着冷藏时间的延长,细胞再培养愈来愈困难。因此,建议科研及生产中不采用此种方法作为保种技术。     

三亚湾春秋浮游植物分布及其与环境因子的关系

为了解三亚湾浮游植物的群落结构特征及其与环境因子之间的关系,笔者于2019年春（4月份）、秋（9月份）两季对三亚湾12个站位的浮游植物及水质进行了网采取样调查。春季采样记录浮游植物共6门82种,秋季共鉴定出浮游植物4门85种,其中硅藻门和甲藻门种类组成占优势,春、秋季硅藻门分别占55种和67种（分别占浮游植物总种类数的67.07%和78.82%）。三亚湾春季浮游植物优势种共4种,分别为角毛藻属（Chaetoceros sp.）、印度角毛藻（Chaetoceros indicus）、三角新角藻（Neoceratium tripos）和薄壁几内亚藻(Guinardia flaccida),其中,角毛藻属（Chaetoceros sp.）为第一优势种。秋季调优势种共9种,分别为菱形海线藻(Thalassionema nitzschioides)、热带骨条藻(Skeletonema tropicum)、霍氏半管藻(Hemiaulus hauckii)、日本星杆藻(Asterionella japonica)、丹麦细柱藻(Leptocylindrus danicus)、劳氏角毛藻(Chaetoceros lorenzianus)、柔弱拟菱形藻(Pseudo-nitzschia delicatissima)、窄隙角毛藻(Chaetoceros affinis)和异角毛藻(Chaetoceros diversus),其中,菱形海线藻为第一优势种。春季多样性指数、均匀度指数和丰富度指数平均分别为3.33、0.80、2.26;秋季多样性指数、均匀度指数和丰富度指数平均分别为4.05、0.79、3.09。RDA分析结果显示,春季总磷、氨氮和水温是影响浮游植物群落组成的主要因素,秋季总氮、盐度和电导率对浮游植物的群落结构影响最大。     

不同微藻对缢蛏稚贝摄食和生长的影响

用实验生态学方法研究了小球藻(Chlorella sp.)、绿色巴夫藻(Pavlova viridis)、小新月菱形藻(Nitzschia closterium f.minutissima)、亚心形扁藻(Platymonas subcordiformis)、微绿球藻(Nannochloropsis oculata)和湛江等鞭金藻(Isochrysis zhanjiangensis)对缢蛏稚贝摄食和生长的影响.结果表明:缢蛏稚贝对6种微藻的清滤率随浓度的增加而增大,当达到一定浓度时清滤率反而下降;在相同浓度下,稚贝对中规格的绿色巴夫藻、小新月菱形藻和湛江等鞭金藻的清滤率显著高于小规格的小球藻、微绿球藻和大规格的亚心形扁藻(P<0.05).不同微藻对缢蛏稚贝的存活率顺序为微绿球藻<小球藻+亚心形扁藻+微绿球藻<小球藻<湛江等鞭金藻<亚心形扁藻<小新月菱形藻<绿色巴夫藻+小新月菱形藻+湛江等边金藻<绿色巴夫藻.初始壳长无显著性差异的稚贝经30 d的生长试验,8个饵料组稚贝的壳长出现明显差异(P<0.05);亚心形扁藻组的日生长率均明显高于其他组(P<0.05),壳长增长率和绿色巴夫藻组无显著性差异(P<0.05).从本试验可知,小球藻、绿色巴夫藻、小新月菱形藻、亚心形扁藻、微绿球藻和湛江等鞭金藻的适宜投喂浓度为30×104、15×104、10×104、6×104、40×104和10×104cell/mL,绿色巴夫藻和亚心形扁藻对缢蛏稚贝的生长效果要好于其他微藻.     

利球等鞭金藻生长抑制物的抑藻机理

    通过球等鞭金藻生长抑制物(1-羟基,丙二酸二乙酯-十二烯酸异丙酯)对6种海洋微藻(牟氏角毛藻、纤细角毛藻、三角褐指藻、新月菱形藻、扁藻和盐藻)的生长及细胞内主要生化成分的影响,对该抑藻物质的抑藻机理进行探讨.结果表明,该生长抑制物对6种微藻生长不仅具有明显的抑制作用,而且对微藻细胞内的一些主要生化成分有显著的影响.在该抑制物作用下,6种微藻细胞内的叶绿素含量显著降低,丙二醛含量以及胞外可溶性蛋白质和多糖含量明显提高,硝酸还原酶、过氧化物酶和超氧化物歧化酶的活性也有不同程度的升高或降低.可见,球等鞭金藻生长抑制物是通过对微藻细胞内的某些主要生化成分的合成过程及其活性的调控,实现对微藻藻细胞的生长控制.     

盐度对牟氏角毛藻生产性培养的影响

采用生产性培养方式,研究盐度对牟氏角毛藻生长的影响。结果表明,牟氏角毛藻细胞生长的适宜盐度范围是18.5～23.5,最适宜的盐度为21.0。低盐度下藻细胞生长缓慢,达到稳定期的时间长;高盐度下藻细胞生长较快,生长周期较短。     

绿色杷夫藻用于罗氏沼虾人工生态系育苗

本文通过培养试验探讨了绿色杷夫藻(Pavlova virgdis)的生长特性，认为该藻具有指数生长期较长、藻群绝对密度较高且维持高峰时间较长等优良特性。该藻具有较广泛的生态适应性，能适应光强500～100001x、温度6～30℃、海水比重1．002～1．016，特别能在低盐度(比重为1．002)、低光照(400～5001x)条件下良好生长，生态上符合罗氏沼虾人工育苗的客观要求。在育苗水体中保持一定数量饵料性微藻并投饲其他生物饵料构成人工生态育苗体系进行工厂化育苗，以角毛藻(Chaetoceros sp．)、小球藻(Chlorella sp．)为对照，比较3种微藻培育罗氏沼虾溞状幼体的效果，发现绿色杷夫藻与角毛藻效果相当而明显好于小球藻。本文作者认为绿色杷夫藻是罗氏沼虾人工生态系育苗的理想用藻。     

绿色杷夫藻用于罗氏沼虾人工生态系育苗

本文通过培养试验探讨了绿色杷夫藻(Pavlova virgdis)的生长特性，认为该藻具有指数生长期较长、藻群绝对密度较高且维持高峰时间较长等优良特性。该藻具有较广泛的生态适应性，能适应光强500～100001x、温度6～30℃、海水比重1．002～1．016，特别能在低盐度(比重为1．002)、低光照(400～5001x)条件下良好生长，生态上符合罗氏沼虾人工育苗的客观要求。在育苗水体中保持一定数量饵料性微藻并投饲其他生物饵料构成人工生态育苗体系进行工厂化育苗，以角毛藻(Chaetoceros sp．)、小球藻(Chlorella sp．)为对照，比较3种微藻培育罗氏沼虾溞状幼体的效果，发现绿色杷夫藻与角毛藻效果相当而明显好于小球藻。本文作者认为绿色杷夫藻是罗氏沼虾人工生态系育苗的理想用藻。     

The effect of solar radiation change on the maize yield gap from the perspectives of dry matter accumulation and distribution

The uneven distribution of solar radiation is one of the main reasons for the variations in the yield gap between different regions in China and other countries of the world.In this study,different solar radiation levels were created by shading and the yield gaps induced by those levels were analyzed by measuring the aboveground and underground growth of maize.The experiments were conducted in Qitai,Xinjiang,China,in 2018 and 2019.The maize cultivars Xianyu 335 (XY335)and Zhengdan 958 (ZD958) were used with planting density of 12×10~4 plants ha~(–1) under either high solar radiation (HSR)or low solar radiation (LSR,70%of HSR).The results showed that variation in the solar radiation resulted in a yield gap and different cultivars behaved differently.The yield gaps of XY335 and ZD958 were 8.9 and 5.8 t ha~(–1) induced by the decreased total intercepted photosynthetically active radiation (TIPAR) of 323.1 and 403.9 MJ m~(–2) from emergence to the maturity stage,respectively.The average yield of XY335 was higher than that of ZD958 under HSR,while the average yield of ZD958 was higher than that of XY335 under LSR.The light intercepted by the canopy and the photosynthetic rates both decreased with decreasing solar radiation.The aboveground dry matter decreased by 11.1% at silking and 21% at maturity,and the dry matter of vegetative organs and reproductive organs decreased by 9.8 and 20.9%at silking and by 12.1 and 25.5% at physiological maturity,respectively.Compared to the HSR,the root weights of XY335 and ZD958 decreased by 54.6 and 45.5%,respectively,in the 0–60 cm soil layer under LSR at silking stage.The aboveground and underground growth responses to different solar radiation levels explained the difference in yield gap.Selecting suitable cultivars can increase maize yield and reduce the yield gaps induced by variation of the solar radiation levels in different regions or under climate change.     

太阳辐射减弱对冬小麦生长发育及产量的影响

[目的]研究太阳辐射减弱对冬小麦生长发育及产量的影响。[方法]通过盆栽模拟试验,设置不同的太阳辐射减弱梯度(自然光、70%太阳辐射、50%太阳辐射),研究太阳辐射减弱对冬小麦干物质积累及产量的影响。[结果]太阳辐射减弱使冬小麦生育期延长,穗、叶和茎等干物质积累减少。太阳辐射减弱下,有效穗数、穗粒数、穗重、千粒重等产量构成指标下降。[结论]太阳辐射减弱对冬小麦的生长发育和产量存在明显的抑制效应。     

自然条件下滤减紫外辐射对烤烟生长及品质的影响

 为研究紫外辐射对丽江特色优质烟叶形成的影响,采用盆栽试验,用100%（对照）,7.6%,62.2%,51.4% 4种不同紫外辐射透过率的透明薄膜进行遮盖,研究其对烤烟生长及品质的影响。结果表明：（1）进行紫外辐射滤减后,烤烟农艺性状与对照差异不明显。（2）对照比各处理在烤烟生长的前期合成更多的光合色素,但从旺长后期开始其降解速度加快;随着紫外辐射增强,光合速率下降,各处理较对照分别下降2,2.4,4.1μmol/（m2·s）。（3）随着紫外辐射强度的降低,烟叶栅栏组织厚度和叶片厚度减小,各处理分别减少6.72,10.04,8.84μm和23.46,28.98,22.98μm。对照与处理之间差异极显著,但处理之间差异不明显。（4）一定范围内紫外辐射的增强能促进烟叶糖类化合物的合成,不利于含氮化合物的积累,对钾和氯含量无明显影响。随着紫外辐射的滤减,上部叶、中部叶、下部叶总糖分别减少2.75%-6.68%,3.37%-6.13%,0.98%-1.66%;上部叶、中部叶、下部叶还原糖分别减少0.42%-2.47%,0.63%-4.22%,3.40%-5.68%;上部叶、中部叶总氮分别增加0.21%-0.71%,0.05%-0.39%,下部叶减少0.07%-0.25%;上部叶、中部叶、下部叶烟碱分别增加0.14%-1.22%,0.05%-0.87%,0.34%-0.82%     

Reducing maize yield gap by matching plant density and solar radiation

Yield gap exists because the current attained actual grain yield cannot yet achieve the estimated yield potential. Chinese high yield maize belt has a wide span from east to west which results in different solar radiations between different regions and thus different grain yields. We used multi-site experimental data, surveyed farmer yield data, the highest recorded yield data in the literatures, and simulations with Hybrid-Maize Model to assess the yield gap and tried to reduce the yield gap by matching the solar radiation and plant density. The maize belt was divided into five regions from east to west according to distribution of accumulated solar radiation. The results showed that there were more than 5.8 Mg ha~(–1) yield gaps between surveyed farmer yield and the yield potential in different regions of China from east to west, which just achieved less than 65% of the yield potential. By analyzing the multi-site density experimental data, we found that the accumulated solar radiation was significantly correlated to optimum plant density which is the density with the highest yield in the multi-site density experiment(y=0.09895 x–32.49, P0.01), according to which the optimum plant densities in different regions from east to west were calculated. It showed that the optimum plant density could be increased by 60.0, 55.2, 47.3, 84.8, and 59.6% compared to the actual density, the grain yield could be increased by 20.2, 18.3, 10.9, 18.1, and 15.3% through increasing plant density, which could reduce the yield gaps of 33.7, 23.0, 13.4, 17.3, and 10.4% in R(region)-1, R-2, R-3, R-4, and R-5, respectively. This study indicates that matching maize plant density and solar radiation is an effective approach to reduce yield gaps in different regions of China.     

商丘地区太阳能资源分布和气候分析

根据商丘地区1965—2007年的逐日日照时数,通过日天文辐射总量、月太阳能辐射经验系数等公式,计算出商丘地区近43年来平均太阳总辐射量,分析了商丘地区太阳能资源的分布和特点,利用总辐射量、气温和天气状况等气候资料探讨了太阳能的利用可行性。研究发现,商丘地区太阳辐射量多,太阳能资源丰富,气温环境良好。因此,太阳能资源的利用具有很大的发展前途和空间。     

Effects of sowing date and ecological points on yield and the temperature and radiation resources of semi-winter wheat

Exploring the effects of sowing date and ecological points on the yield of semi-winter wheat is of great significance. This study aims to reveal the effects of sowing date and ecological points on the climate resources associated with wheat yield in the Rice–Wheat Rotation System. With six sowing dates, the experiments were carried out in Donghai and Jianhu counties, Jiangsu Province, China using two semi-winter wheat varieties as the objects of this study. The basic seedlings of the first sowing date (S1) were planted at 300×10⁴ plants ha⁻¹, which was increased by 10% for each of the delayed sowing dates (S2–S6). The results showed that the delay of sowing date decreased the number of days, the effective accumulated temperature and the cumulative solar radiation in the whole growth period. The yields of S1 were higher than those of S2 to S6 by 0.22–0.31, 0.5–0.78, 0.86–0.98, 1.14–1.38, and 1.36–1.59 t ha^–1, respectively. For a given sowing date, the growth days increased as the ecological point was moved north, while both mean daily temperature and effective accumulative temperature decreased, but the cumulative radiation increased. As a result, the yields at Donghai County were 0.01–0.39 t ha^–1 lower than those of Jianhu County for the six sowing dates. The effective accumulative temperature and cumulative radiation both had significant positive correlations with yield. The average temperature was significantly negatively correlated with the yield. The decrease in grain yield was mainly due to the declines in grains per spike and 1 000-grain weight caused by the increase in the daily temperature and the decrease in the effective accumulative temperature.     

荆条孤立冠层天空开度与太阳辐射透射率关系研究

为寻求用植物冠层分析仪（PCA）确定荆条灌丛孤立冠层太阳辐射的透射率,分别选择阴天和晴天条件,实测荆条灌丛下和裸地对照的太阳总辐射和散射辐射,以确定冠层的总辐射、散射辐射、直接辐射透射率。同时对荆条灌丛孤立冠层进行冠层分析,确定全部冠层的天空开度DIFN_总,以及-80°~+80°不同方位角方向的天空开度DIFN_总。以便对比分析冠层分析的天空开度与实测太阳辐射透射率的关系。结果表明,散射辐射透射率与冠层开度DIFN_总相关极为显著,相关系数接近于1;用DIFN_总计算的冠层下散射辐射比实测值低估了36.8%;太阳直接辐射所在方位的PCA冠层分析的DIFN_直与冠层下直接辐射的透过率关系密切,在-80°~+80°方位角范围内都呈抛物线型变化,-80°~0°范围内关系极为密切,而20°~+80°范围内DIFN_直偏低。PCA冠层分析确定的冠层天空开度DIFN_总可以用来确定冠层下的散射辐射;不同方位角的天空开度DIFN_直可以表达冠层下的太阳直接辐射透射率,这对解决冠层下太阳直接辐射无法测定的问题很有意义。     

不同氮素处理下棉花冠层光合有效辐射与其产量及构成因素的相关分析

【目的】研究不同氮素处理棉花冠层关键生育时期,吸收性光合有效辐射(APAR) 和光合有效辐射吸收系数( FAPAR)与棉花产量和产量构成因素之间的相关性,为快速、非破坏性地监测棉花长势和产量预测提供理论支持。【方法】利用线性光量子传感器,获取棉花新陆早61号和新陆早72号2品种4氮素处理5个生育时期的冠层光合有效辐射(PAR),计算出APAR和FAPAR,分别与实测籽棉产量和其构成因素建立相关关系。【结果】2个棉花品种4种氮素处理的冠层APAR、FAPAR随生育期表现出相似的变化规律,冠层APAR在整个生育期呈现“M”的变化趋势;冠层FAPAR呈现出先上升后下降的趋势,其较高值都出现在开花结铃期和盛铃期,除盛花期外,2品种4氮素处理的其它4个生育时期FAPAR均为N₃>N₂>N₁>N₀的;5个生育时期的FAPAR与籽棉产量和单株有效铃数均达到显著和极显著相关关系,而只有开花结铃期的APAR与二者达到极显著相关(α=1%,n=24),APAR和FAPAR与其它产量构成因素未达到显著相关关系。利用开花结铃期FAPAR与籽棉产量和单株有效铃数相关最高的线性函数模型对其估算,籽棉产量和单株有效铃数的实测值与估测值之间均呈现极显著线性关系,预测精度分别达93.20%、93.25%。【结论】棉花不同氮素处理影响棉花冠层APAR、FAPAR的变化,利用棉花开花结铃期的冠层FAPAR可以预测棉花产量和单株有效铃数。     

福建龙海太阳辐射与粮食作物光合生产关系研究

为了提高粮食作物光合生产力,2006～2009年在福建省龙海市设研究基点,观测太阳辐射和粮食作物的光合生产.①依据太阳辐射和日照百分率,建立龙海分季节月太阳总辐射经验计算式.②太阳辐射与干物质积累量和经济产量呈正相关,水稻齐穗至成熟期的太阳辐射对稻谷产量有决定性影响.③龙海基点早稻、晚稻、马铃薯等一年三熟作物全生育期平...