基于PLS 和组合预测方法的冬小麦收获 指数高光谱估测

【目的】通过遥感反演测量收获指数(HI),可节省时间和人力,但需要提高精度。通过权重最优组合算法改善收获指数估算精度,为基于多时相多光谱信息的HI遥感估算提供新方法参考。【方法】利用测定的冬小麦多个关键生育期的冠层光谱数据,对筛选的44种常用植被指数与实测收获指数进行相关性分析,挑选出每个育期中5种最优的典型植被指数;应用偏最小二乘(PLS)的方法建模,分别得到基于单个生育期光谱信息的HI遥感估测模型;借鉴组合预测原理,应用组合预测方法对全部单生育期的各HI光谱模型赋予最优权重,最终构建基于多生育期数据的HI光谱组合预测模型。【结果】(1)利用PLS后,单一生育期的建模结果较单一植被指数有所改进,但仍有待提高;(2)应用组合预测原理的HI组合预测模型,显著改善了HI的估测精度,R2达到0.55,较单生育期的建模预测,提升了13%。【结论】基于多生育期信息的组合预测方法,对各单一生育期HI预测模型赋予最优权重进行优化组合,实质间接利用了各生育期对作物HI形成的贡献,显著提高冬小麦收获指数的估测精度,是一种新颖的作物HI遥感估测方法。     

基于MODIS NDVI的冬小麦收获指数遥感提取

为研究利用遥感技术反演冬小麦收获指数，以河北省馆陶县为例，使用2016年、2017年、2018年连续3年冬小麦生长期内的MODIS NDVI时间序列数据，并基于农学观点和冬小麦生理机制，提出了一种构建收获指数（HI）相关参数的新模型HI_MEAN,并与已有相关模型HI_NDVI和HI_NDVI＿SUM进行比较，最后建立了收获指数的预测模型。结果表明，与收获指数参数模型HI_NDVI和HI_NDVI＿SUM相比，模型HI_MEAN的精度最高。进一步反演了2018年河北省馆陶县的冬小麦收获指数，与实测冬小麦收获指数对比，其r²为0.632 9,说明收获指数参数模型HI_MEAN在反演冬小麦收获指数时，理论基础更加合理，同时也具有最高的精度。同时，收获指数参数模型HI_MEAN构建也为后续的以及其他作物收获指数提取研究提供了一种可行的思路。     

水稻收获指数分子遗传研究进展

水稻收获指数是指稻谷产量与生物产量的比值。众多研究表明,作物的收获指数与其产量密切相关。收获指数对作物品种改良的作用已得到育种和生理学家的普遍认同,高收获指数已成为水稻高产育种的一个重要指标。深入了解水稻收获指数的遗传基础是有效开展水稻高收获指数育种的前提和基础。就水稻收获指数的生物学意义、与产量的关系,特别是其遗传研究的进展进行综述,并就水稻收获指数研究存在的问题和前景进行探讨。     

小麦的收获指数和几个生理特性的遗传

按照作物生理学的观点,一个小麦品种的光合生产力和收获指数(HI)越高,籽粒产量也越高。光合生产力则决定于光合器官的性质——大小、寿命和光合效率。作物生理学以叶面积持续期(LAD)和净同化率(NAR)作为光合生产力的指标,其意义是:LAD:是叶面积对时间的积分。NAR:是单位叶面积在单位时间内的干物质净积累。作物的生物产量等于全生育期内LAD和NAR的乘积之和,其籽粒产量则可由下式     

中国非禾谷类大田作物收获指数和秸秆系数

收获指数和秸秆系数对作物生产研究和秸秆资源评估具有重要意义。本研究主要根据2006—2010年文献的田间实测数据,研究了非禾谷类大田作物在中国大陆主产省份的收获指数和秸秆系数。结果表明:大豆收获指数和秸秆系数全国平均值分别为0.42和1.50,6个省份的收获指数为0.35～0.47,秸秆系数1.13～1.86。马铃薯收获指数和秸秆系数的全国平均值分别为0.59和0.71,甘薯分别为0.69和0.45,木薯分别为0.64和0.50。其中,11个省份的马铃薯、甘薯和木薯等薯类作物收获指数为0.55～0.77、秸秆系数0.30～1.17。棉花皮棉收获指数和秸秆系数全国平均值分别为0.15和2.91,5个省份棉花的皮棉收获指数为0.12～0.18,秸秆系数2.41～4.09。花生的收获指数和秸秆系数全国平均数分别为0.50和1.14,6个省份花生收获指数为0.41～0.54,秸秆系数0.85～1.43。油菜的收获指数和秸秆系数全国平均数分别为0.26和2.87,6个省份油菜收获指数为0.24～0.28,秸秆系数2.57～3.17。向日葵收获指数和秸秆系数全国平均数分别为0.32和2.63,4个省份向日葵收获指数为0....     

不同栽培模式下铁皮石斛中重金属含量及健康风险评估

为研究重金属对不同栽培模式的铁皮石斛食用安全性影响,利用ICP-MS技术测定了大棚栽培、树栽培和石壁栽培的铁皮石斛中重金属含量。结果表明:3种不同栽培模式下的铁皮石斛中重金属Pb、Cd、As和Cu均低于WM/T 2-2004《药用植物及制剂外经贸绿色行业标准》,但树栽培和石壁栽培的Pb含量要显著高于大棚栽培。利用日摄入量(EDI)和复合污染指数(HI)对3种不同栽培模式下的铁皮石斛进行健康风险评价,发现Pb、Cd、As、Cu和Al的日摄入量远低于FAO/WHO和USEPA推荐的参考剂量;HI估算结果显示Pb、Cd、As、Cu和Al的HI值均低于1,表明正常消费不同栽培模式下的铁皮石斛基本不产生重金属健康风险。     

中国作物的收获指数

本文对中国300个农业气象试验站各种作物的收获资料进行统计分析,计算了收获指数、谷草比和有关的统计参数。结果指出：1.各作物的平均收获指数差别较大,主要粮食作物的收获指数在0.35—0.45之间,谷草比在0.55—0.80之间。2.收获指数和谷草比的变动范围较大,对于同一作物,绝大多数样本的谷草比都分布在平均值附近,而少数的可以偏离平均值较远。3.由粮食产量推算秸秆量,对于大面积的估算有较满意的结果,而对于个别地块,其误差可能较大。4.一些主要作物谷草比的频率分布曲线接近正态分布,而多数则属正偏类型。5.同一作物在丰、平、歉年的平均谷草比各不相同,一般丰年大,歉年小,平年介于其间。6.谷草比与产量水平有关,随着产量的提高而增加,其关系可用一元回归方程表示。     

世界麦类作物夏播研究综述

世界上栽培的冬麦,多在秋、冬季播种,翌年夏季收获,栽培的春麦,在早春播种,当年夏季或初秋收获。而夏播麦类作物,则是利用前期自然降雨较多,后期天气晴朗凉爽的气候条件,在夏、秋季播种,当年秋、冬季收获。近些年来,世界上有些国家相继进行了麦类作物夏播的研究工作,并取得了一定的成果。     

贵港市春花生、沙姜、粉葛间套种栽培技术

科学利用花生、沙姜、粉葛等作物进行间套种栽培,重点介绍粉葛的育苗、田间管理、病虫害防治、适时收获等栽培技术,以为作物的间套种栽培提供参考。     

马铃薯间套种模式及效益分析

山东省春马铃薯播种早，收获早，生育期６０多天。采取保护地栽培措施，可提早到５月中下旬收获。马铃薯与其它作物实行间套种栽培在时间上是可行的，马铃薯利用早春的土地和光能资源，间套作物利用中后期的土地和光能资源，从而达到充分利用自然资源、提高经济效益的目的...     

Web2.0,以个人为中心的互联网时代的到来

本文介绍了Web2．0的知识和背景，对Web2．0出现的基础以及典型技术和应用作了阐述，同时对其作出了前景展望。     

盐胁迫对葡萄苗期多胺和激素代谢的影响

【目的】 研究盐胁迫条件下,葡萄叶片中多胺含量、多胺氧化酶、多胺合成酶活性以及激素的动态变化,研究不同盐胁迫强度对多胺类物质及激素代谢的影响。【方法】 采用盆栽基质培养模拟盐胁迫环境,设置4个NaCl处理梯度:0 (CK)、1、2和3 g/kg。多胺和激素含量的测定采用高效液相色谱法,多胺合成及分解酶活性的测定采用紫外分光光度计比色法。【结果】 盐胁迫处理后,葡萄叶片中多胺含量和脱落酸含量较对照而言显著增加,玉米素含量显著降低,随胁迫时间的延长,Put、Spm、Spd、ABA以及PAO、DAO、ADC、ODC、SAMDC活性均呈先上升后下降趋势,在10 d及10 d后达到峰值。ZT呈逐渐下降的趋势,并随胁迫强度增大而减小;进行显著性分析后,叶片中多胺含量与Put、Spm、Spd含量呈极显著正相关,DAO、ADC、ODC活性与Put含量呈显著正相关,PAO与SAMDC活性与Spm和Spd含量也呈极显著正相关。【结论】 3种多胺经酶的合成代谢后和激素共同缓解葡萄苗所遭受到的盐胁迫,期间主要发生作用的是多胺合成酶,盐胁迫下多胺与激素含量之间的变化关系也十分密切。     

市级综合气象信息分析与管理系统的设计与实现

以抚顺地区3个国家基本站50余年气象资料为依托,采用Microsoft Excel工作表实现由气候和农业气候2部分构成的气象与农业综合信息处理系统的基本思路、方法、内容、用途和使用情况。为了实现气候分析及应用的科学化、客观化、系统化、规范化、程序化及连续化的业务目标,按业务流程设计与实现的,包括资料处理、气候趋势模拟、气候预测、气候鉴定、季节性信息化处理、农作物产量预报、气候生产潜力分析等一系列内容在内的系统建设。关键是解决了大量的计算问题,建立了区域性通用模式。     

Multi-variable grey model (MGM (1,n,q)) based on genetic algorithm and its application in urban water consumption

Urban water consumption has some characteristics of grey because it is influenced by economy, population, standard of living and so on. The multi-variable grey model （MGM（1,n））, as the expansion and complement of GM（1,1） model, reveals the relationship between restriction and stimulation among variables, and the genetic algorithm has the whole optimal and parallel characteristics. In this paper, the parameter q of MGM（1,n） model was optimized, and a multi-variable grey model （MGM（1 ,n,q）） was built by using the genetic algorithm. The model was validated by examining the urban water consumption from 1990 to 2003 in Dalian City. The result indicated that the multi-variable grey model （MGM（1,n,q）） based on genetic algorithm was better than MGM（1,n） model, and the MGM（1,n） model was better than MGM（1,1） model.     

Molecular detection of virulence genes in Campylobacter species isolated from livestock production systems in South Africa

Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.     

红苕饲粮中添加铜和/或喹乙醇对猪生产性能及某些血液生化指标的影响

选体重约38公斤的长白(♂)×成华(♀)杂交猪20头,随机分为四组,饲予四种不同的饲粮,研究饲粮中添加铜和/或喹乙醇对猪生产性能和某些血液生化指标的影响。结果表明:基础组、加铜组、加喹乙醇组和两者同时加组全期日增重分别为674、761、796、678克,日采食量分别为2.50、2.65、2.74、2.40公斤,饲料利用率分别为3.73、3.49,3.44、3.54,添加铜和/或喹乙醇对试验第65天血清铜兰蛋白、尿素氨及屠宰率、背膘厚和眼肌面积无显著影响(p>0.05);添加铜使65天血清碱性碱酸酶活性极显著增高(p<0.01),添加喹乙醇有使之升高的趋势,两者同时添加时,碱性酸磷酶活性降低。     

不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响

 【目的】通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异,探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量。【方法】以木薯品种南美119为材料,采用“3414”方案,在粤北翁源进行大田试验。试验共设14个处理。【结果】施肥处理的氮素主要分配到地上部,不施肥处理的氮素则主要分配到根部;不同施肥处理的磷素均主要分配到地上部;不施肥处理和不施钾处理的钾素主要分配到根部,不施氮处理的钾素在根、冠间分配较均衡。在木薯不同生长阶段,植株氮磷钾含量均呈下降趋势,但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理。处理N2P2K2的氮、磷、钾含量和积累量在各生育期均为最大,不施肥处理（N0P0K0）的氮、磷、钾含量和积累量在各生育期均为最小（P＜0.05）。产量最高的是N2P3K2处理,为22 694.06 kg·hm-2,其次是N2P2K2处理,为21 417.87 kg·hm-2。【结论】木薯产量、氮磷钾养分积累及其在根冠间的分配,对施肥水平高度敏感, 适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量,又可以提高产量。在粤北坡岗地木薯生产中,氮素最重要,在氮素得到满足的条件下,磷素较钾素更重要。在本试验条件下,氮磷钾养分最佳用量为358.80 kgN·hm-2、89.10 kg P2O5·hm-2和187.50 kg K2O·hm-2。     

Current progress on genetic interactions of rice with rice blast and sheath blight fungi

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.     

Virus Location and Lymphocyte Apoptosis in Lymph Nodes of Piglets Infected with PCV-2

The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ （PCV-2）. Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups： control group （n = 3）, piglets inoculated with PCV-2 alone （PCV-2, n = 3）, and PCV-2 inoculated and KLH immunostimulated group （PCV-2 ＋ KLH, n = 3）. Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling （TUNEL） and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 ＋ KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 ＋ KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 ＋ KLH piglets were significantly higher than those for the control group （P〈0.05 and P〈0.01）. The proliferation index （PI） was 0.17_＋0.01, 0.12_＋0.01 and 0.12_＋0.04 in the control, PCV-2, and PCV-2 ＋ KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o     

内脐蠕孢属、平脐蠕孢属和凸脐蠕孢属的研究

本文报道了平脐蠕孢属(Bipolaris)一个新种,一个新组合,5个新记录以及凸脐蠕孢属(Exserohilum)一个新记录。讨论了内脐蠕孢属(Drechslera)、平脐蠕孢属、凸脐蠕孢属与长蠕孢属(Helminthosporium)的关系,并就我国已报道的长蠕孢属真菌按Alcorn等~([1,3,4,5,24])人的意见,逐个进行了订正。