农科大学生移动学习模型的构建与实践

以云南农业大学《大学英语》课程网络移动自主学习为例,结合农业院校学生特点,提出了基于学习共同体的移动学习模式,通过实践与调查问卷重点分析了《大学英语》网络课程平台的移动学习情况和共同体的学习模式效果,并给出了相应的改进建议,为农业高校如何开展移动自主学习奠定了基础。     

番茄斑驳花叶病毒在我国茄科作物上的发生及生物学特性

【目的】鉴定烟草花叶病毒属（Tobamovirus）新种番茄斑驳花叶病毒（Tomato mottle mosaic virus,ToMMV）当前在我国茄科作物上的发生危害情况、主要分布地区和自然寄主,明确其主要寄主范围、传播途径和致病性等生物学特性。【方法】利用RT-PCR方法对2013—2017年采自我国云南、贵州、四川、海南、湖南、河南、陕西、山东、湖北、浙江、辽宁、西藏和内蒙古13个省（自治区）,表现为花叶、皱缩、畸形、黄化、坏死等疑似病毒病症状的茄科作物辣椒、番茄、茄子、马铃薯和烟草等样品进行ToMMV的检测。分别将ToMMV进行摩擦接种和注射接种,对感染ToMMV的珊西烟获得的种子及由种子萌发的幼苗进行ToMMV检测,对由健康种子萌发且在含有ToMMV毒源土壤中生长的6—8叶龄辣椒和番茄幼苗进行ToMMV检测,以此开展ToMMV传播方式的测试。在茄科、葫芦科、豆科和十字花科等6科30种植株上开展ToMMV的寄主范围鉴定和不同辣椒、番茄材料对ToMMV的抗性鉴定。【结果】我国13个省（区）共采集茄科作物疑似病毒病样品1 622份,ToMMV的平均检出率为2.59%,目前ToMMV已在我国云南、湖南、海南、辽宁、陕西、西藏和内蒙古7个省（区）发生。其中云南、湖南、海南、陕西和西藏的辣椒上有ToMMV的发生,而云南、海南、辽宁及内蒙古的番茄上有ToMMV的发生,平均检出率分别为2.51%和3.46%,尚未在茄子、马铃薯和烟草样品中检测到ToMMV的侵染。ToMMV可通过摩擦、注射、种子带毒及土壤带毒进行传播,且种子带毒率越高,对种苗生长的影响越大;寄主范围测试发现,ToMMV可侵染几乎所有供试的茄科和十字花科植物,及部分豆科和葫芦科植物。筛选出对ToMMV免疫的辣椒材料1份、高抗的辣椒材料2份以及对ToMMV高抗的番茄材料2份。【结论】ToMMV目前已在我国辣椒、番茄上发生,人工条件下ToMMV的寄主范围较广,致病力强,在我国有逐渐扩散和流行的趋势,很可能会成为未来蔬菜作物尤其是茄科作物上危害严重的主要病毒之一。     

地方农业院校大学生环境价值观与伦理观调查与分析

采用问卷调查的方式,对云南农业大学1077名在校大学生的环境价值与伦理观进行了调查与分析,结果表明:(1)云南农业大学学生环境价值观呈多元化,持“人类中心主义”、“动物中心主义”、“生物中心主义”和“生态中心主义”的学生比例分别为24％、25％、21％和31％.(2)50％-87％的学生认同“不同地域公平”,67％-100％的学生赞同“代际公平”的可持续发展环境伦理观,54％-83％的学生“非常关心,热爱并敬畏大自然”,对环境价值的构成认识较好.(3)部分年级专业的学生中,20％-38％和18％-30％分别持有“地域不公平”和“代际不公平”的环境伦理观,20％-38％和18％-30％的学生持有“不同地域和代际”不公平发展的环境伦理观,20％-32％的学生只关心身边的环境,33％-52％和36％-64％的学生持有“牺牲环境来发展经济”和“不愿意付出自身利益以保护环境”的认识.(4)学生的环境价值观和伦理观存在专业与年级间的差异.     

云南水稻条纹病毒致病性

 近几年来,由介体灰飞虱传播的水稻条纹叶枯病是云南滇西及滇中地区水稻上的主要病害,对水稻的生产造成很大的损失,为此,笔者采用生物学接种方法开展了云南水稻主栽品种对条纹叶枯病的抗性鉴定及RSV致病性分化分析。供试的12个水稻品种对水稻条纹病毒的抗性鉴定结果表明,部分粳稻品种对RSV表现为高感,而籼稻品种则多表现为抗病或免疫。采自重病区的5个RSV分离物在水稻上的致病性分化不明显,致病性的强弱主要体现在对小麦和玉米等的侵染差异,为此可以将5个RSV分离物分为3组,但组内分离物之间致病性又有所不同,致病性最强为楚雄分离物,其次为保山、大理、禄劝分离物,致病性最弱为陆良分离物。     

2013-2014年云南主要稻区病毒病调查及RSV的分子变异

于2013-2014连续两年对云南主要水稻种植区的水稻病毒病进行了调查,发现当前为害云南水稻的病毒病主要有水稻条纹叶枯病、南方水稻黑条矮缩病、水稻矮缩病和水稻齿叶矮缩病。其中,条纹叶枯病是当前为害云南水稻最严重的病毒病,部分田块最高发病率可达15.0%;其次是水稻矮缩病,调查田块最高发病率达10.0%;南方水稻黑条矮缩病的平均发病率达5.3%;水稻齿叶矮缩病只在局部地区发生且发病率都不高。对云南当前发生较普遍的RSV不同分离物RNA3基因间隔区(IR3)及RNA4基因间隔区(IR4)开展了分子变异分析。根据不同RSV分离物IR3、IR4核苷酸序列构建系统进化树,所分析的RSV分离物均可被划分为两个组,部分云南分离物和云南以外的中国、日本、韩国分离物聚在Ⅰ组,其余绝大多数云南分离物单独聚在Ⅱ组。不同RSV分离物的IR3和IR4长度差异较大,按每10个核苷酸的长度差异进行划分,均可划分为A、B、C三种不同的类型。部分RSV云南分离物IR3、IR4中有17-21nt的序列与其水稻、小麦和大麦等寄主的部分序列相同,这可能是病毒在进化过程中与寄主植物发生了重组。云南RSV分离物的IR3、IR4分子变异较大,可能与其特殊的地理、生态条件有一定的相关性。     

云南美人蕉病毒病病原鉴定

In this study,the causal agents were identified from Canna indica viral diseased plants in Yunnan Province.The diseased C.indica plants mainly exhibited the symptoms like veinal chlorosis and yellowing,streak mosaic or interveinal chlorosis,while older leaves always showed veinal necrosis as well as chlorosis.Viral pathogens were detected by RT-PCR/PCR in 24 diseased C.indica samples collected from Kunming and Yuxi City in Yunnan Province.The results indicated that the main C.indica-infecting viruses were canna yellow mottle virus (CaYMV),bean yellow mosaic virus (BYMV),sugarcane mosaic virus (SCMV).CaYMV showed the highest detection rate of 87.5 %,whereas,the BYMV had the lowest rate of 16.7% in the 24 samples.Co-infections of CaYMV+SCMV,CaYMV+BYMV and CaYMV+SCMV+BYMV were also detected in the diseased samples.However,cucumber mosaic virus (CMV),tobamovirus,luteovirus,orthotospovirus,begomovirus and umbravirus were not detected in these samples.This is the first report of CaYMV and SCMV infecting C.indica in Yunnan province.     

百合斑驳病毒云南分离物 全基因组序列分析及CP结构预测

 对云南嵩明百合上发生的百合斑驳病毒(Lily mottle virus, LMoV)进行全基因组序列测定及分析,并对LMoV嵩明分离物(LMoV-SMi1、LMoV-SMi2)和玉溪分离物(LMoV-YXi1、LMoV-YXi2)外壳蛋白(coat protein,CP)基因进行序列比较,发现云南的LMoV分为2个类群,玉溪分离物属于种群I,嵩明分离物属于种群II。2个类群间的核苷酸和氨基酸同源性分别为86.7%~89.5%、90.1%~92.7%,玉溪分离物和嵩明分离物相比,cp基因发生了3个核苷酸的缺失。对国内外LMoV所有分离物的cp基因氨基酸序列进行系统进化分析,结果表明所有LMoV分离物可划分为2个种群,种群I分离物较种群II分离物几乎均存在1个苏氨酸缺失的差异。此外,对LMoV-SMi2的CP相关特性和空间结构进行了初步预测,认为该蛋白为球状,具有较强的表面可能性,不存在跨膜区域,大多数区域能够形成主要的抗原决定簇,主要集中在aa12-22、aa31-42、aa83-99、aa179-191、aa215-223、aa249-259区段,可作为制备抗血清选择抗原的参考。LMoV-SMi2和LMoV-YXi1在二级结构和三级结构上存在一定的差异,但总体空间结构差异不大。     

云南美人蕉病毒病病原鉴定

In this study,the causal agents were identified from Canna indica viral diseased plants in Yunnan Province.The diseased C.indica plants mainly exhibited the symptoms like veinal chlorosis and yellowing,streak mosaic or interveinal chlorosis,while older leaves always showed veinal necrosis as well as chlorosis.Viral pathogens were detected by RT-PCR/PCR in 24 diseased C.indica samples collected from Kunming and Yuxi City in Yunnan Province.The results indicated that the main C.indica-infecting viruses were canna yellow mottle virus (CaYMV),bean yellow mosaic virus (BYMV),sugarcane mosaic virus (SCMV).CaYMV showed the highest detection rate of 87.5 %,whereas,the BYMV had the lowest rate of 16.7% in the 24 samples.Co-infections of CaYMV+SCMV,CaYMV+BYMV and CaYMV+SCMV+BYMV were also detected in the diseased samples.However,cucumber mosaic virus (CMV),tobamovirus,luteovirus,orthotospovirus,begomovirus and umbravirus were not detected in these samples.This is the first report of CaYMV and SCMV infecting C.indica in Yunnan province.     

侵染云南鸡蛋果的病毒种类鉴定及CMV cp 基因序列分析

Viral diseased Passiflora edulis samples showing mosaic, shrinking, chlorosis, and malformation were collected from Yuxi, Wenshan, Dehong, and Xishuangbanna in Yunnan Province. Forty diseased samples were detected by RT-PCR/PCR using degenerate primers of members in genera of Umbravirus, Tobamovirus, Luteovirus, Orthotospovirus, Begomovirus, Badnavirus, Potyvirus and specific primers of cucumber mosaic virus (CMV). Results showed that CMV, telosma mosaic virus (TeMV) and papaya leaf curl Guangdong virus (PaLCuGdV) were detected in the diseased P. edulis samples. CMV showed the highest detection rate of 27.5 %, while TeMV and PaLCuGdV had the rates of 20.0% and 7.5% respectively among the P. edulis samples. Mixed infections of PaLCuGdV+CMV, PaLCuGdV+TeMV and CMV+TeMV were also found in these samples. The 657 nucleotide (nt) CMV full-length coat protein (CP) gene was cloned and sequenced from two diseased samples in Yuxi (YYXi-JDG, Acc. No. MW495062) and Xishuangbanna (YXSBN-JDG, Acc. No. MW495063), respectively. These two CMV isolates shared 97.3% identity of nt sequence with each other, while had 76.9%-97.7% and 77.0%-98.2% nt identity with other CMV isolates, respectively. Phylogenetic tree showed that the two CMV isolates from P. edulis belonged to CMV subgroup Ⅰ, and no obvious geographic differentiation and host specificity relationship was found among the selected 33 CMV isolates worldwide.     

农科大学生移动学习模型的构建与实践

以云南农业大学《大学英语》课程网络移动自主学习为例,结合农业院校学生特点,提出了基于学习共同体的移动学习模式,通过实践与调查问卷重点分析了《大学英语》网络课程平台的移动学习情况和共同体的学习模式效果,并给出了相应的改进建议,为农业高校如何开展移动自主学习奠定了基础。