杜鹃花是杜鹃花属的总称，是具有很高的观赏和经济价值的著名木本植物。热胁迫是影响杜鹃花生长的主要环境因子。褪黑素近年来被报道可以缓解非生物胁迫对植物的影响。然而，褪黑素在杜鹃花中的作用尚不清楚。本研究探讨了褪黑素对热胁迫下杜鹃花的影响及其潜在机制。叶绿素荧光结果表明，喷施200 µmol L^-1褪黑素对杜鹃花抵抗热胁迫效果最佳。为了阐明褪黑素如何限制高温的不利影响，本研究分别在25、35和40°C处理下分析了杜鹃花叶片中褪黑素含量、光合参数、Rubisco酶活性和ATP含量。结果表明，与对照相比，外源喷施褪黑素提高了杜鹃花叶片中褪黑素含量、热应激下的电子传递速率、光系统II和I活性、Rubisco酶活性和ATP含量。转录组分析结果表明，许多热胁迫下的差异表达基因富集在光合作用途径，这些基因中的大部分均在热处理后下调表达，且在无褪黑素处理的植株中下调幅度大于外源喷施褪黑素处理的植株。本研究鉴定出RhPGR5A、RhATPB、RhLHCB3和RhRbsA作为关键基因。综合以上结果，我们推测褪黑素通过调控包括RhRbsA在内的特定基因的表达，促进光合电子传递，提高卡尔文循环酶活性，增加ATP的产生，由此提高了热应激下的光合效率和CO₂同化能力。因此，施用外源褪黑素可提高杜鹃花对热胁迫的耐受性。

肌醇及其衍生物在调节植物非生物逆境耐受性过程中发挥着重要作用。肌醇-1-磷酸合成酶MIPS（myo-inositol-1-phosphate synthase）是肌醇生物合成限速酶，本研究发现，在苹果植株中过表达MdMIPS1基因不仅能提高肌醇生物合成，而且还能提高植株耐旱性。研究表明，肌醇可能通过提高渗透保护剂（如葡萄糖、蔗糖和脯氨酸）的积累和改善活性氧清除相关抗氧化酶活性，提高苹果干旱耐受性。此外，在模拟黄土高原土壤环境的长期中度水分亏缺条件下，MdMIPS1过表达苹果植株表现为水分利用效率显著提高，这可能主要与肌醇生物合成增加协同调节植株渗透平衡和气孔孔径密切相关。综上所述，本研究揭示了苹果MdMIPS1介导的肌醇生物合成在植株耐旱性和水分利用效率调控过程中的积极作用。

多巴胺是一种儿茶酚胺和一种抗氧化剂，在应对逆境时起作用，它与植物激素相互作用以介导植物发育。目前，关于苹果中多巴胺功能的研究较少。本研究开发了一种用于分析苹果种质中的多巴胺测定方法，以阐明多巴胺在苹果树的组织分布、发育变化、昼夜变化和逆境响应。首先，对所提出的方法进行了验证，定量的线性范围在0.1-20 ng mL^-1范围内稳定，仪器、日间精密度和样品重复性相对标准偏差分别为1.024%、5.607%和7.237%，加标回收率大于100%，表明该方法的可行性及其适用于快速分析苹果属种质中的多巴胺。接下来，测量了322个苹果组织中的多巴胺含量。结果表明，苹果的多巴胺水平较低，叶片中多巴胺的平均含量高于果皮和果肉。多巴胺在栽培品种和野生种质中向右偏。最后，分析了组织特异性、发育变化、昼夜变化和对逆境的响应。在栽培品种‘皮诺娃’（Malus domestica）中，多巴胺含量在叶芽中最高，在果肉中最低。叶片和果肉中多巴胺含量随着栽培品种‘凉香’（Malus domestica）的生长发育而降低。与对照相比，干旱或盐胁迫后苹果叶片的多巴胺含量更高。在本研究中，建立了一种基于HPLC-MS的苹果多巴胺检测方法，并证明是一种稳健的方法。本研究为未来阐明苹果树中多巴胺的组织分布、发育变化、昼夜变化和逆境响应提供了一个框架。

连阴雨天气导致田间湿度增大，诱发田间霉菌的生长繁殖，并侵染农作物导致田间霉变的发生。在大豆生长后期，因连阴雨天气导致的田间霉变严重影响大豆的产量和品质。为探究田间霉变诱导大豆品质劣变的机制，本研究利用人工降雨室模拟连阴雨天气，诱发大豆籽粒田间霉变，结合转录组学和多种代谢检测平台，解析田间霉变胁迫下大豆品质劣变的生化机理。研究结果表明，田间霉变影响大豆的外观品质，霉变大豆籽粒皱缩、变形，并出现霉斑。田间霉变使大豆籽粒中蛋白质、多糖等储藏性物质的含量降低，导致籽粒百粒重显著下降。转录组分析发现，田间霉变使大豆籽粒中氨基酸代谢、糖酵解、三羧酸循环、脂肪酸β氧化等初生代谢过程加强。代谢组分析结果也表明，霉变大豆籽粒中多种氨基酸、糖类物质、有机酸的含量显著增加，而脂肪酸的含量则显著下降。与此同时，大豆异黄酮作为一类重要的抗逆活性物质，其生物合成在转录水平和代谢水平均受到田间霉变的诱导。田间霉变诱发大豆籽粒的防御机制，通过分解和消耗储藏性物质为防御体系的构建提供能量和底物，但储藏性物质的消耗导致了大豆品质劣变。本研究为深入了解大豆籽粒田间霉变的机制提供了重要的理论基础，同时也为抗田间霉变大豆品种的筛选指明方向。

籽粒灌浆速率（GFR）在小麦产量形成过程中起着关键作用，但由于表型调查困难等原因，对其遗传解析研究甚少。本研究测定了1个重组自交系群体和1个自然群体籽粒灌浆性状，基于高密度图谱进行相关性状的连锁分析和全基因组关联分析。在染色体 1B、4B和5A上鉴定到17个稳定的QTLs。 其中IWB19555-IWB56078 连锁区间对性状 GFR₁、GFR_max、KL、KW、KT 和TKW具有多效性，表型变异解释率（PVE）为13.38%（KW）- 33.69%（TKW）。检测到198个显著性状关联位点（MTAs）分布在除了3D和4D之外的染色体上。GFR的主要关联位点包括 IWB44469（11.27%）、IWB8156（12.56%）和IWB24812（14.46%）。检测到IWB41019是籽粒大小相关的重要多效性位点。通过GWAS鉴定到的IWB35850与连锁分析获得的QGFR_max2B.3-11位于同一区域，该区域包含两个高置信候选基因。检测到两个重要的粒重相关 QTL与灌浆速率 QTL定位到同一区间。这些发现有助于解析 GFR 的遗传基础，为小麦产量性状 QTL候选基因预测提供理论依据。

本文研究不同采收时间（间隔1-2周）对赣南脐橙果汁的化学成分及其抗氧化能力的影响。研究结果表明，随着果实逐渐成熟，果汁中可溶性固形物 (TSS)、总酚 (TPC)、总黄酮（TFC）、蔗糖以及橙皮苷含量均逐渐增加，在成熟后期阶段略有下降。可滴定酸 (TA)、维生素C (V_C) 和柠檬苦素的含量在整个成熟期均呈下降趋势。果糖、葡萄糖以及芸香柚皮苷含量在整个采收期均有波动，没有明确的上升或下降趋势。运用三种体外抗氧化筛选平台（DPPH, FRAP, ABTS）对果汁的抗氧化活性进行评价，结果表明采收时间对赣南脐橙果汁体外抗氧化能力无显著性影响 (p>0.01)。在此基础上，本文运用主成分分析和皮尔逊相关性分析对不同采收期赣南脐橙果汁的化学成分及抗氧化能力进行了归类和相关性分析。本文首次深入系统的研究了采收时间对赣南脐橙果汁的化学成分及抗氧化能力的影响，研究成果有望为赣南脐橙品质评价提供重要科学依据。同时，我们的研究结果表明，在成熟后期采摘的赣南脐橙果汁不仅柠檬苦素含量低，而且具有很好的抗氧化能力和很高的黄酮类化合物含量，非常适合用于果汁加工。

斑点叶（spl）突变体属于一种植物类病斑突变体。我们通过甲基磺酸乙酯（EMS）诱变小麦栽培品种国麦301，获得了一些类病斑突变体，其中一种因其叶片上有白色条纹而被命名为白色条纹叶（wsl）突变体。本文报告这个新的小麦突变体wsl的遗传和基因定位。在整个生育期，突变体wsl的叶片上均有白色条纹出现。随着植株的生长，白色条纹加重，坏死斑面积增大。突变体wsl在拔节前长势较弱，拔节过后长势逐渐恢复。突变体wsl旗叶的长和宽、单株有效穗数和千粒重均显著低于其野生型亲本国麦301。遗传分析表明，wsl的白色条纹性状受１对隐性核基因控制，命名为wsl。利用两个F2群体（wsl×中国春和wsl×济麦22），通过SSR分子标记连锁分析，将wsl基因定位在小麦6BS染色体臂上。在wsl×中国春杂交分离群体中，筛选到4个与wsl基因连锁的标记，Xgpw1079-Xwmc104-Xgwm508-wsl-Xgpw7651，遗传距离分别为7.1, 5.2, 8.7和4.4 cM。在wsl×济麦22杂交分离群体中，筛选到3个与wsl基因连锁的标记，Xgwm508-Xwmc494-Xgwm518-wsl，遗传距离分别为3.5, 1.6和8.2 cM。参考中国春基因组序列，wsl位于6BS染色体88 Mb （Xgwm518）~ 179 Mb （Xgpw7651）之间的91 Mb物理区间内。突变体wsl是研究小麦叶片发育分子机制的重要新种质。

地下水资源紧缺是华北平原冬小麦生产面临的一个严峻的挑战，急需先进的节水技术在冬小麦生产上的应用。为了探讨微喷灌技术在冬小麦生产上的节水潜力，我们设置了五个处理，传统畦灌TF1（拔节期和开花期分别灌溉75 mm灌水量）；微喷灌MSI1（拔节期、开花期和灌浆中期分别微喷30 mm灌水量）; 微喷灌MSI2（起身期、拔节期、开花期和灌浆中期分别微喷30 mm灌水量）；微喷灌MSI3（起身期、拔节期、孕穗期、开花期和灌浆中期分别微喷30 mm灌水量）；微喷灌MSI4（返青期、起身期、拔节期、孕穗期、开花期和灌浆中期分别微喷30 mm灌水量），于2012-2015三个生长季通过大田试验进行了研究。研究结果表明，与TFI相比，MSI1和MSI2的水分利用效率分别增加了22.5和16.2%，同时分别降低耗水量17.6和10.8%。在不考虑降雨年型的情况下，与常规畦灌TFI相比，MSI1或MSI能够在降低20-40%灌溉水的前提下保证冬小麦稳产或显著增产。与TFI相比，MSI3的产量和水分利用效率也分别提高了4.6%和11.7%。微喷灌可以实现少量多次的灌溉，降低了土壤的紧实度并有利于小麦根系的下扎，进而有利于关键生育期光合同化物的生产。总之，与TF1相比，MSI1和MSI2能够在降低灌溉用水20-40%的前提下实现稳产或增产，这将为华北平原冬小麦节水高效生产提供一定的技术支撑。

氮素是水稻取得高产的重要因素之一。除高产外，优质已成为当前水稻生产的又一迫切要求。灌浆期是水稻产量和品质形成的关键时期。而氮素对籼稻籽粒灌浆特性的影响及其与稻米品质的关系仍不清楚。通过大田栽培试验，研究了施氮条件下籽粒灌浆的关键特性与稻米研磨品质、外观品质和蒸煮食味品质的变化。结果表明，施氮延长了强、弱势粒灌浆的持续时间。弱势粒的平均灌浆速率（G_mean）和最大灌浆速率（G_max）与垩白粒率、垩白度和直链淀粉含量呈正相关关系。弱势粒达到最大灌浆速率的时间（T_max G）与糙米率、精米率和整精米率呈正相关关系。垩白粒率、垩白度与最高黏度、崩解值呈负相关关系。2016年和2017年两优培九和Y两优2号两个品种均在施氮后出现直链淀粉含量下降，粗蛋白含量增加。相关性分析说明，直链淀粉含量较低的Y两优2号蒸煮食味品质较好，可能是其弱势粒的最大灌浆速率（G_max）和平均灌浆速率（G_mean）高于两优培九所引起的。施氮后弱势籽粒灌浆时间的延长和达到最大灌浆速率时粒重的增加可以提高中籼稻的碾磨品质、外观品质和蒸煮食味品质。

气候变化严重影响农业生产，危及粮食安全。中国是世界第二大玉米生产国，也是最大的玉米消费国。分析气候变化对玉米单产的影响可以为国家和国际经济和政治提供有效的指导。面板模型无法确定数据集的组间异方差、截面相关和组内自相关，因此我们采用广义最小二乘模型（FGLS）来评估1979-2016年气候变化对中国玉米单产的影响。得到以下结果：（1）在1979-2016年期间，温度升高对中国玉米单产产生了负面影响。温度每升高1℃，玉米单产减少5.19 kg 667 m^-2（1.7％）。在此期间，降水仅略有增加，因此其对玉米单产的影响可以忽略不计。降水量每增加1 mm，玉米单产将增加0.043 kg 667 m^-2（0.014％），这是微不足道的。（2）气候变化对玉米单产的影响在空间上有所不同，在中国南部地区受到的影响更大。在该地区，温度每升高1℃，玉米单产下降7.49 kg 667 m^-2，而温度对中国北方玉米单产的影响不明显。降水量每增加1 mm，华南玉米单产增加0.013 kg 667 m^-2，而华北玉米增加0.066 kg 667 m^-2。（3）玉米作物对气候变化的适应力强，1990-2016年期间的中国南北部温度的边际效应均小于1979-2016年期间。

Received  21 December, 2017    Accepted  14 March, 2018

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The cultivar Ganoderma lucidum Hunong 5 was obtained using cross-breeding.  Hunong 5 has high commercial value due to its high polysaccharide and triterpene content.  This is the first report of using a DNA pooling method to develop a stable sequence characterized amplified region (SCAR) marker for rapid identification of the G. lucidum Hunong 5 cultivar.  The SCAR marker was developed by first generating and sequencing a distinctive inter simple sequence repeat (ISSR) fragment (882 bp) from G. lucidum Hunong 5 cultivar.  A stable SCAR primer pair GLH5F/GLH5R were obtained to identify the cultivar and the SCAR marker is a DNA fragment of 773 bp.

Ecological engineering involves the use of plants to promote establishment, survival and efficiency of natural enemies in agricultural systems.  Some plant species may be hosts or provide resources to some pest species.  We assessed the risks and benefits of sesame (Sesamum indicum L.), as a nectar source for seven economically important Lepidopteran pest and four parasitoid species in a range of vegetable crop systems.  Our results showed that the mean longevities of arthropod parasitoids Pteromalus puparum (L.), Encarsia sophia (Girault & Dodd) and male Microplitis tuberculifer (Wesmael) were significantly extended when fed on sesame flowers compared to the water control.  Sesame flowers had no effect on adult longevities and fecundities of six out of the seven Lepidoptera pest species tested except Plutella xyllostella (L.) females laid more eggs when fed on sesame flowers.  It is likely that the increased fecundity is due to accessibility to nectar at the bottom of corolla because of their smaller body sizes.  Our findings provide a first step towards better understanding of the risks and benefits of using sesame to implement ecological engineering for the management of vegetable pests.

Crop modelling can facilitate researchers’ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 (DSSAT) model together with the CENTURT soil model were employed to investigate the effect of low nitrogen (N) input on wheat (Triticum aestivum L.) yield, grain N concentration and soil organic carbon (SOC) in a long-term experiment (19 years) under a wheat-maize (Zea mays L.) rotation at Changping, Beijing, China.  There were two treatments including N0 (no N application) and N150 (150 kg N ha^–1) before wheat and maize planting, with phosphorus (P) and potassium (K) basal fertilizers applied as 75 kg P₂O₅ ha^–1 and 37.5 kg K₂O ha^–1, respectively.  The DSSAT-CENTURY model was able to satisfactorily simulate measured wheat grain yield and grain N concentration at N0, but could not simulate these parameters at N150, or SOC in either N treatment.  Model simulation and field measurement showed that N application (N150) increased wheat yield compared to no N application (N0).  The results indicated that inorganic fertilizer application at the rates used did not maintain crop yield and SOC levels.  It is suggested that if the DSSAT is calibrated carefully, it can be a useful tool for assessing and predicting wheat yield, grain N concentration, and SOC trends under wheat-maize cropping systems.

We carried out a pool culture experiment to determine the optimal water treatment depth in loam and clay soils during the late growth stage of super rice.  Three controlled water depth treatments of 0–5, 0–10 and 0–15 cm below the soil surface were established using alternate wetting and drying irrigation, and the soil water potential (0 to –25 kPa) was measured at 5, 10 and 15 cm.  A 2-cm water layer was used as the control.  We measured soil enzyme activities, root antioxidant enzyme activities, chlorophyll fluorescence parameters, and rice yield.  The results showed that the 0–5-cm water depth treatment significantly increased root antioxidant enzyme activities in loam soil compared with the control, whereas soil enzyme activities, chlorophyll fluorescence parameters and yield did not differ from those of the control.  The 0–10- and 0–15-cm water depth treatments also increased root antioxidant enzyme activities, whereas soil enzyme activities, chlorophyll fluorescence parameters and yield decreased.  In clay soil, the soil enzyme activities, root antioxidant enzyme activities, chlorophyll fluorescence parameters, and yield did not change with the 0–5-cm water treatment, whereas the 0–10- and 0–15-cm water treatments improved these parameters.  Therefore, the appropriate depths for soil water during the late growth period of rice with a 0 to –25 kPa water potential were 5 cm in loam and 15 cm in clay soil.

Genomic selection has been demonstrated as a powerful technology to revolutionize animal breeding.  However, marker density and minor allele frequency can affect the predictive ability of genomic estimated breeding values (GEBVs).  To investigate the impact of marker density and minor allele frequency on predictive ability, we estimated GEBVs by constructing the different subsets of single nucleotide polymorphisms (SNPs) based on varying markers densities and minor allele frequency (MAF) for average daily gain (ADG), live weight (LW) and carcass weight (CW) in 1 059 Chinese Simmental beef cattle.  Two strategies were proposed for SNP selection to construct different marker densities: 1) select evenly-spaced SNPs (Strategy 1), and 2) select SNPs with large effects estimated from BayesB (Strategy 2).  Furthermore, predictive ability was assessed in terms of the correlation between predicted genomic values and corrected phenotypes from 10-fold cross-validation.  Predictive ability for ADG, LW and CW using autosomal SNPs were 0.13±0.002, 0.21±0.003 and 0.25±0.003, respectively.  In our study, the predictive ability increased dramatically as more SNPs were included in analysis until 200K for Strategy 1.  Under Strategy 2, we found the predictive ability slightly increased when marker densities increased from 5K to 20K, which indicated the predictive ability of 20K (3% of 770K) SNPs with large effects was equal to the predictive ability of using all SNPs.  For different MAF bins, we obtained the highest predictive ability for three traits with MAF bin 0.01–0.1.  Our result suggested that designing a low-density chip by selecting low frequency markers with large SNP effects sizes should be helpful for commercial application in Chinese Simmental cattle.

Extreme meteorological disaster effects on grain production is mainly determined by the interaction between danger degree of hazard-induced factors and vulnerability degree of hazard-affected bodies.  This paper treats physical exposure, sensitivity of the response to the impact, and capabilities of disaster prevention and mitigation as a complex system for vulnerability degree of hazard-affected bodies, which included the external shocks and internal stability mechanism.  Hazard-induced factors generate external shocks on grain production systems though exposure and sensitivity of hazard-affected body, and the result can be represented as affected area of grain.  By quantile regression model, this paper depicts the quantitative relationship between hazard-induced factors of extreme meteorological disaster and the affected area in the tail of the distribution.  Moreover, the model of production function have also been utilized to expound and prove the quantitative relationship between the affected area and final grain output under the internal stability mechanism of the agricultural natural resources endowment, the input factors of agricultural production, and the capacity of defending disaster.  The empirical study of this paper finds that impact effects of drought disaster to grain production system presents the basic law of “diminishing marginal loss”, namely, with the constant improvement of the grade of drought, marginal affected area produced by hazard-induced factors will be diminishing.  Scenario simulation of extreme drought impact shows that by every 1% reduction in summer average rainfall, grain production of Jilin Province will fell 0.2549% and cut production of grain 14.69% eventually.  In response to ensure China’s grain security, the construction of the long-term mechanism of agricultural disaster prevention and mitigation, and the innovation of agricultural risk management tools should be also included in the agricultural policy agenda.

  The safety of feeding transgenic cry1Ab/cry1Ac rice (a genetically modified (GM) rice variety) to broilers was examined from an immunological perspective. Hatchling Arbor Acres chickens (240) were assigned to two dietary treatments (diets containing GM or non-GM rice) with 12 replicates per group and 10 birds per replicate. Traits were measured on one randomly selected bird from each replicate at d 21 and 42. The 42-d feeding trial revealed that cry1Ab/cry1Ac rice had no significant effect relative to non-GM rice on body weight and the immune organ indices. No significant pathological lesion in the spleen and bursa of Fabricius was found in the GM rice group. There were no significant differences in serum concentrations of immunoglobulin Y (IgY), IgM, interleukin 4 (IL-4) and IL-6 between the two groups at d 21 or 42, except for IL-6 being higher (P<0.05) in the GM-fed chickens at d 42. There were no differences in the T and B lymphocyte transformation rate and CD4+/CD8+ ratio between the two groups at d 42. Additionally, there was no significant difference between the two diets in expression of relevant genes viz. the major histocompatibility complex class II beta chain (BLB2), interferon beta 1 (IFNβ), tumour necrosis factor alpha-like (TNFα) and toll-like receptor 4 (TLR4) in the spleen and bursa of Fabricius. All the data demonstrated that transgenic cry1Ab/cry1Ac rice had no adverse effect on these aspects of immune function of broilers during 42-d feeding trial. Transgenic rice was therefore indistinguishable from non-GM rice in terms of short-term feeding in chickens.  

Rice panicles are composed of many branches with two types of extreme grains, the superior and the inferior. Traditionally, it has been well accepted that earlier flowers result in superior grains and late flowers generate inferior grains. However, these correlations have never been strictly examined in practice. In order to determine the accurate relationship between superior and inferior grains and the flowering order, we localized all the seeds in a panicle in four distinct rice species and systematically documented the rice flowering order, flower locations and the final grain weight for their relationships. Our results demonstrated that the grain weight is more heavily determined by the position of the seeds than by the flowering order. Despite earlier flowering has a positive correlation with the grain weight in general, grains from flowers blooming on the second day after anthesis generally gained the highest weight. This suggests earlier flowers may not result in superior grains. Therefore, we concluded that superior and inferior grains, commonly determined by grain weight, are not fully correlated with the flowering order in rice. Following the order of the grain weight, the superior grains are generally localized at the middle parts of the primary branches, whereas inferior grains were mainly on the last two secondary branches of the lower half part of the panicle. In addition, the weight of inferior grains were affected by spikelet thinning and spraying with exogenous plant growth regulators, indicating that physiological incompetence might be the major reason for the occurrence of the inferior grains.

In order to establish double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for detection of duck or goose flavivirus, polyclonal antibody against the flavivirus strain JS804 in geese and monoclonal antibody against the E protein of flavivirus strain JS804 in geese were used as the capture antibody and detection antibody, respectively. The optimal dilution of the capture antibody and detecting antibody capable of detecting the flavivirus strain JS804 in geese were 1:3 200 and 1:160 in the check-board titration, respectively. The reaction time of sample was 1 h, and the optimal working dilution of HRP-labeled goat-anti-mouse IgG was 1:10 000. The positive standard value was 0.247 (OD450 nm). The geese flavivirus could be detected at a minimal concentration of 1.875 μg mL-1. The ELISA had no cross-reaction with Newcastle disease virus (NDV), Avian influenza virus (AIV), Infectious bronchitis virus (IBV), Infectious bursal disease virus (IBDV), Duck hepatitis virus (DHV), and Gosling plague virus (GPV). Twenty clinical samples were detected by the DAS-ELISA and RT-PCR respectively, with the agreement rate of 75%. The results revealed that the DAS-ELISA possessed favorable specificity and higher sensitivity, indicating a suitable method for rapid detection of the duck or goose flavivirus.

Powdery mildew (Blumeria graminis) is one of the most destructive crop diseases infecting winter wheat plants, and has devastated millions of hectares of farmlands in China. The objective of this study is to detect the disease damage of powdery mildew on leaf level by means of the hyperspectral measurements, particularly using the continuous wavelet analysis. In May 2010, the reflectance spectra and the biochemical properties were measured for 114 leaf samples with various disease severity degrees. A hyperspectral imaging system was also employed for obtaining detailed hyperspectral information of the normal and the pustule areas within one diseased leaf. Based on these spectra data, a continuous wavelet analysis (CWA) was carried out in conjunction with a correlation analysis, which generated a so-called correlation scalogram that summarizes the correlations between disease severity and the wavelet power at different wavelengths and decomposition scales. By using a thresholding approach, seven wavelet features were isolated for developing models in determining disease severity. In addition, 22 conventional spectral features (SFs) were also tested and compared with wavelet features for their efficiency in estimating disease severity. The multivariate linear regression (MLR) analysis and the partial least square regression (PLSR) analysis were adopted as training methods in model development. The spectral characteristics of the powdery mildew on leaf level were found to be closely related with the spectral characteristics of the pustule area and the content of chlorophyll. The wavelet features performed better than the conventional SFs in capturing this spectral change. Moreover, the regression model composed by seven wavelet features outperformed (R2=0.77, relative root mean square error RRMSE=0.28) the model composed by 14 optimal conventional SFs (R2=0.69, RRMSE=0.32) in estimating the disease severity. The PLSR method yielded a higher accuracy than the MLR method. A combination of CWA and PLSR was found to be promising in providing relatively accurate estimates of disease severity of powdery mildew on leaf level.

The developmental competence of porcine parthenotes cultured in porcine zygote medium-3 (PZM-3) and North Carolina State University-23 (NCSU-23) media was investigated. After in vitro maturation oocytes were electro-activated, and the subsequent developmental competence, rates of apoptotic, fragmented and arrested embryos from the two media were evaluated. Also, the ratio of mRNA expression of Bcl-2 and Bax gene was determined. Results demonstrated that cleavage, blastocyst, hatched blastocyst rates, and blastocyst cell numbers were significantly higher in PZM-3 than in NCSU-23. The rate of fragmented embryos in PZM-3 was lower than in NCSU-23 on d 1 and 3 (P<0.05) while the percentage of arrested embryo was lower in PZM-3 than in NCSU-23 on d 4 and 5 (P<0.05). TUNEL positive signals were higher in NCSU-23 than in PZM-3 from d 3 to 7 (P<0.05). The ratios of Bcl-2 and Bax mRNA expression in embryos were higher on d 5 than on d 3 and 1 in PZM-3 (P<0.05). In contrast, the ratios of Bcl-2 and Bax mRNA expression in embryos on d 1 were higher than on d 3 and 5 in NCSU-23 (P<0.05). Additionally, the ratios of Bcl-2 and Bax mRNA expression in embryos in PZM-3 were higher than in NCSU-23 on d 3 and 5 (P<0.05). In conclusion, lower apoptotic embryo rates and down-regulating Bax together with up-regulating expression of Bcl-2 transcripts may be responsible for the better developmental competence of porcine parthenotes in PZM-3.