Detection of Internal Leaf Structure Deterioration Using a New Spectral Ratio Index in the Near-Infrared Shoulder Region

Spectral reflectance in the near-infrared （NIR） shoulder （750-900 nm） region is affected by internal leaf structure, but it has rarely been investigated. In this study, a dehydration treatment and three paraquat herbicide applications were conducted to explore how spectral reflectance and shape in the NIR shoulder region responded to various stresses. A new spectral ratio index in the NIR shoulder region （NSRI）, defined by a simple ratio of reflectance at 890 nm to reflectance at 780 nm, was proposed for assessing leaf structure deterioration. Firstly, a wavelength-independent increase in spectral reflectance in the NIR shoulder region was observed from the mature leaves with slight dehydration. An increase in spectral slope in the NIR shoulder would be expected only when water stress developed sufficiently to cause severe leaf dehydration resulting in an alteration in cell structure. Secondly, the alteration of leaf cell structure caused by Paraquat herbicide applications resulted in a wavelength-dependent variation of spectral reflectance in the NIR shoulder region. The NSRI in the NIR shoulder region increased significantly under an herbicide application. Although the dehydration process also occurred with the herbicide injury, NSRI is more sensitive to herbicide injury than the water-related indices （water index and normalized difference water index） and normalized difference vegetation index. Finally, the sensitivity of NSRI to stripe rust in winter wheat was examined, yielding a determination coefficient of 0.61, which is more significant than normalized difference vegetation index （NDVI）, water index （WI） and normalized difference water index （NDWI）, with a determination coefficient of 0.45, 0.36 and 0.13, respectively. In this study, all experimental results demonstrated that NSRI will increase with internal leaf structure deterioration, and it is also a sensitive spectral index for herbicide injury or stripe rust in winter wheat.     

马蹄金野生种与栽培种在自然降温过程中的抗寒性研究

在自然降温过程中,马蹄金Dichondra repens的野生种与栽培种叶片内的可溶性糖、游离脯氨酸的含量、相对电导率发生明显变化.其中,脯氨酸先降低后升高;可溶性糖先上升后下降;相对电导率逐渐升高.在观测的温度范围内,野生马蹄金叶内的游离脯氨酸含量高于栽培种;可溶性糖含量上升幅度远大于栽培种;相对电导率的上升幅度低于栽培种.结果表明:马蹄金的野生种比栽培种耐寒.     

早稻氮磷钾施肥类别归属的贝叶斯判别方法研究

【目的】在测土配方施肥中,“测土”是实现合理施肥微观指导的关键技术手段。本研究针对高度分散经营的耕地代表性土样采集难、测试费用高、花费时间长等“测土”难题,探讨早稻氮磷钾施肥类别归属的统计模式识别技术。【方法】利用闽东南80个早稻氮磷钾田间肥效试验资料作为样本,采用欧氏距离–离差平方和法进行系统聚类分析,建立区域早稻施肥类别。在此基础上,根据田块氮磷钾施肥量及其产量结合地力信息等数量指标,应用贝叶斯判别准则探讨具体田块的施肥类别归属。【结果】在确保空白区产量和平衡施肥产量均值在两两施肥类别间具有统计显著差异的前提下,闽东南早稻最多可划分为6个氮磷钾施肥类别。多元统计检验表明,6个施肥类别的类内协方差矩阵差异不全相等,据此建立了各个施肥类别的贝叶斯判别函数。结果表明,原始试验数据标准化处理可大幅度提高判别准确性,监测样本的回代误判率和交叉误判率分别只有1.2% 和1.3%,预留6个试验点的84个处理的氮、磷、钾施肥量和产量试验资料的施肥类别归属的判别正确率达到81.0%。【结论】统计模式识别原理及其贝叶斯判别准则可用于早稻氮磷钾施肥类别归属决策,判别准确性能够满足推荐施肥的精度要求。     

比较两种免疫缺陷动物人肝癌模型的肿瘤生物学特性

为探讨裸小鼠和裸大鼠(rnu/rnu)两种免疫缺陷动物人肝癌皮下移植与原位移植后肿瘤生长和转移等生物学特性的差异,将Huh-7细胞株接种至裸小鼠皮下成瘤后采用组织学完整的组织块移植于裸小鼠和裸大鼠皮下和肝脏,建立皮下和原位移植模型,观察所建立模型的皮下和原位成瘤率、移植瘤生长、侵袭和转移情况,同时进行了病理组织学、超微结构、细胞增殖周期和异倍体的观察.裸大鼠皮下移植瘤模型肿瘤的生长速度远远大于裸小鼠.原位移植瘤模型裸大鼠成瘤率高达95.0%,其肺转移率形成率为50.0%,均高于裸小鼠.此实验证明应用裸大鼠较裸小鼠更适用于建立肝癌的皮下和原位移植模型,为探讨肝癌转移的生物学机制和抗转移治疗提供了理想的动物模型.     

闽西不同杉木无性系子代测定林幼林生长的比较

为筛选适宜闽西地区推广的杉木优良无性系,对福建漳平五一国有林场7年生不同杉木无性系子代测定林进行调查,比较不同无性系的速生性,估算不同无性系幼林生长的现实增益.结果表明:供试的86个不同无性系平均树高、胸径和材积分别为5.87 m、7.82 cm和0.0255 m3,分别是福建洋口国有林场第1代种子园混合子代实生苗的1.13、1.10和1.55倍;不同无性系生长存在较大差异,M34无性系生长最快,树高、胸径和材积生长量分别为1.02 m.a-1,1.47 cm.a-1和0.0052m3.a-1;初步筛选出17个杉木速生优良无性系,与漳平五一国有林场初级嫁接种子园实生苗相比,这些无性系的树高、胸径和材积平均现实增益值分别达12.67%、15.86%和47.80%.     

菊黄东方鲀♀×红鳍东方鲀♂杂交后代早期形态特征及生长速度的比较

对菊黄东方鲀、红鳍东方鲀及其杂交后代的早期形态特征和生长速度进行了比较。在全长5 cm和10 cm时,形态上的主要差异是:(1) 菊黄东方鲀的尾鳍为浅黄色,无黑杂色;红鳍东方鲀的尾鳍为黑色,其杂交后代与菊黄东方鲀相似,尾鳍浅黄色,略带黑色;(2) 菊黄东方鲀背部皮刺无或极少超出侧线,超出部分与体背黑斑不相交;红鳍东方鲀背部皮刺超出侧线,超出部分与黑斑相交,向下延伸至腹部,其杂交后代背部皮刺超出侧线,与体背黑斑部分相交,向下未能延伸至腹部;(3) 菊黄东方鲀背部皮刺向前延伸至两眼连接线,红鳍东方鲀向前延伸至两鼻孔连接线,其杂交后代超过两眼连接线而未达鼻孔连接线。以尾鳍颜色和皮刺的分布特征可以区分幼鱼阶段的菊黄东方鲀、红鳍东方鲀及其杂交后代。在体长为5 cm及10 cm时分别选取了2个和4个框架参数建立判别函数,判别菊黄东方鲀、红鳍东方鲀及其杂交种的准确率达到96.8%和100%。经过110 d的饲养,红鳍东方鲀、杂交东方鲀以及菊黄东方鲀的平均体长分别达到(110.24±3.78)、(101.16±6.56)和(82.92±4.29) mm,体质量分别为(35.68±5.04)、(33.00±6.24)和(20.99±3.00) g,无论体长还是体质量,都是红鳍东方鲀>杂交东方鲀>菊黄东方鲀,差异极显著。研究表明,菊黄东方鲀♀与红鳍东方鲀♂杂交,其后代早期形态与母本菊黄东方鲀相似,生长比红鳍东方鲀慢,而比菊黄东方鲀快,具有显著的经济杂交价值。     

不同氮素水平下夏玉米冠层光辐射特征的研究

对不同氮素水平(0、7·5和15g·m-2)下3个夏玉米品种的群体光辐射特征进行了研究。结果表明:叶面积指数(LAI)随生育进程呈抛物线单峰变化,且生长约55d时各氮肥处理的LAI值及其差异性达到最大;平均叶簇倾斜角(MLIA)在抽雄期达到最大且随施氮量的增加而变小;散射辐射透过系数(TCDP)和直接辐射透过系数(TCRP)随生育进程和施氮量增加均呈递减的趋势,TCRP随天顶角增加呈先增后减的趋势,以37·5°时最大;消光系数在抽雄期最小,且随天顶角增大而增大,随施氮量的变化因生长期而异;叶片分布(LD)值随生育进程和施氮量呈增加趋势,随方位角增大呈先增后减的趋势,以180°~270°最大。此结果为实现夏玉米冠层结构改良和高产、稳产目标奠定了基础。     

Effects of Anhua dark tea on ApoE-/- mice with non-alcoholic fatty liver induced by high-fat diet

AIM To explore the effects of Anhua dark tea on the prevention and treatment of non-alcoholic fatty liver induced by high-fat diet in apolipoprotein E knockout (ApoE^-/-) mice and the relevant mechanisms. METHODS Male ApoE^-/- mice (n=50, 8 weeks old) were randomly divided into model group, atorvastatin group, and high-, medium- and low-dose Anhua dark tea groups, with 10 mice in each group. In addition, 10 homologous wild-type male C57BL/6J mice were selected as normal control group. The ApoE^-/- and wild-type mice were fed with the same amount of high-fat feed and common feed for 17 weeks, respectively, and intervened by the corresponding drugs and normal saline. At the end of the experiment, HE staining was used to observe the histopathological changes of the liver. The levels of alanine aminotransfease (ALT), aspartate aminotransfease (AST), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the liver tissues were detected. The mRNA expression levels of hydroxymethyl glutaryl coenzyme A reductase (HMGCR), peroxisome proliferator-activated receptor-γ (PPAR-γ) and steroyl coenzyme A desaturase-1 （SCD-1） were detected by RT-qPCR to observe the lipid synthesis. RESULTS In model group, increased volume, smooth surface, tight membrane and dull edge of the liver were observed, and microscopic images with HE staining showed the formation of vacuoles with varying sizes, indicating the success of establishing the model. Compared with the model group, the degree of liver steatosis, the levels of ALT, AST and MDA, and the mRNA expression of HMGCR, SCD-1 and PPAR-γ in different doses of Anhua dark tea groups were significantly decreased, while the activity of SOD and GSH-Px was increased (P<0.05). The effect of Anhua dark tea in high- and medium-dose groups was better than that in low-dose group (P<0.05). CONCLUSION Anhua dark tea prevents high-fat diet-induced non-alcoholic fatty liver in ApoE^-/- mice. The mechanism may be related to reducing lipid synthesis by inhibition of HMGCR, SCD-1 and PPAR-γ expression, and protecting liver cells through anti-oxidative activity.