内蒙古玉米机械粒收质量及其影响因素研究

2013～2017年在内蒙古开展9组机械粒收品种筛选与技术集成示范,共获得97个品种/组合139个品次样本数据。收获时采取机械粒收测产方式对其中6组试验进行产量和收获质量测试,结果表明,收获时子粒破碎率均值为9.89%,产量总损失率均值为5.77%,高于国标(GBT-21961—2008)规定≤5%的要求。子粒含水率均值为26.78%,含水率与破碎率、杂质率呈显著正相关。按子粒含水率和单产水平2个指标采用双向平均法作图进行品种分类,对97个供试品种/组合进行初步筛选,吉单66等15个品种表现出子粒含水率低、单产水平高的特点,适合机械粒收。     

烟草疫霉SSR分子标记的开发与初步应用

 为开发烟草疫霉的SSR分子标记,利用MISA软件搜索烟草疫霉基因组序列中的 SSR位点,共发现1 311个SSR位点,优势SSR位点为二核苷酸和三核苷酸,分别占总 SSR 位点的56.45%和39.36%;根据分析到的SSR位点使用Primer 5.0软件设计48对SSR引物,以7株烟草疫霉的DNA 为模板对这些引物进行筛选,共获得扩增条带清晰且具有多态性的SSR引物20对,然后使用其中的6对SSR对32株烟草疫霉进行UPGMA聚类分析,遗传相似系数在 0.60~1.00 之间,在相似系数0.70水平上,可将其划分为3个类群,类群I包含29个菌株,类群II包含1个菌株,类群III包含2个菌株,显示出较低的遗传分化水平。这些SSR引物的开发将为研究我国烟草疫霉的遗传多样性、群体遗传结构以及遗传图谱构建等奠定基础。     

太子参叶斑病病原菌鉴定及防治药剂筛选

采用形态学结合分子系统学方法对引起贵州黄平县和六枝道地中药材种植基地太子参叶斑病的病原菌进行鉴定,并以菌丝生长法对75%百菌清可湿性粉剂、70%甲基硫菌灵可湿性粉剂、37%苯醚甲环唑可湿性粉剂、40%氟硅唑乳油以及1%申嗪霉素悬浮剂进行了室内药效筛选。结果表明:引起贵州太子参叶斑病的病原菌为Ascochyta versabilis,该病原菌为太子参病害新记录;5种杀菌剂除75%百菌清可湿性粉剂2 000倍对A.versabilis的抑菌率较低外(51.4%),其余4种供试杀菌剂均具有较强的抑菌作用。70%甲基硫菌灵可湿性粉剂2 000倍、37%苯醚甲环唑可湿性粉剂2 000倍和40%氟硅唑乳油2 000倍对A.versabilis的生长具有较强的抑制作用,其抑制率均高于90%;1%申嗪霉素悬浮剂2 000倍对该病原菌的抑制率为72.3%。     

加拿大一枝黄花防除化学药剂的筛选及其应用效能

为获得防除加拿大一枝黄花的有效药剂,揭示化学防治的主要特征,采用单一药剂、单一药剂+助剂、混合药剂及触杀型+内吸型药剂4种药剂处理方式进行田间药效试验。结果表明,25%环嗪酮可溶液剂7 500mL/hm~2、41%草甘膦异丙铵盐水剂6 000mL/hm~2+有机硅300g/hm~2、20%氯氟吡氧乙酸乳油750mL/hm~2+20%草铵膦水剂8 740mL/hm~2、41%草甘膦异丙铵盐水剂6 000mL/hm~2+20%草铵膦水剂8 740mL/hm~2对加拿大一枝黄花的防效显著。施药35d后,株防效均达到100.00%,地上部分鲜重防效分别达到80.2%、90.4%、83.0%和88.9%。除25%环嗪酮可溶液剂致植株根腐效果不佳外,其余3种药剂组合地下部分鲜重防效均达到70%以上,可作为加拿大一枝黄花防除的典型药剂进行推广。组合药剂喷施方式表明,内吸型和触杀型药剂喷施顺序不同,对加拿大一枝黄花的防除效果存在明显差异。以单一药剂最大剂量防除加拿大一枝黄花的效果显示,喷施大剂量单一药剂不一定能明显提高防治效果。     

海洋源高产葡萄糖氧化酶细菌的筛选和主要酶学性质

从海洋环境中筛选高产葡萄糖氧化酶的海洋细菌, 为生产葡萄糖氧化酶提供新的菌种资源。采集海泥、海水及珊瑚样品,采用亚甲基蓝平板显色培养的方法初步分离产酶细菌,再对分离菌株进行显色培养,挑选产酶优势菌株,用液态摇瓶发酵的方法测定优势菌株的产酶能力,然后检测温度及酸碱度对酶活性的影响,并对优势菌株进行形态鉴定、生化鉴定以及16S rDNA基因序列鉴定。从海泥样品中初筛得到几株产葡萄糖氧化酶的细菌,其中菌株MS-4产酶活力最高,该菌在常规LB液体培养条件下葡萄糖氧化酶活力达到8.8 U·mL^-1;所产酶最适作用温度为14 ℃,最适pH为7.0,在25 ℃以下活性稳定;经过综合鉴定MS-4是蜡状芽孢杆菌,其中生化鉴定和基因序列鉴定的结果显示,该菌与蜡状芽孢杆菌的相似度分别为98.8%和100%。实验结果说明,MS-4具有相对较高的产葡萄糖氧化酶能力,可作为低温食品保鲜用葡萄糖氧化酶的生产用菌进行开发和研究。     

特色烤烟品种筛选试验

对11 个烤烟品种进行了特色品种筛选试验。结果表明,南江三号的田间生长势最好; 红花大金元、云烟85、Va116 田间生长势较好,经济价值较高;GY2、GY5、GY8、G140 的田间生长 势最差,经济价值低;南江3 号的产量为152.83kg/亩、产值为2081.54 元/亩,在11 个烤烟品种中 最高;贵烟4 号的产值为1836 元/亩,烤后烟叶叶片薄厚适中,油分充足,组织为疏松,上中等烟比 例达到90.61%,烤后烟叶质量最好。     

基于转录组测序的油梨 EST-SSR 引物开发

利用转录测序技术,开发油梨表达序列标签-简单重复序列（EST-SSRs）,为 SSR 标记在油梨种质资源鉴定、 品种选育及遗传连锁图谱构建奠定基础。采用 Illumina 二代测序的技术,共获得 37 639 条无冗余的序列,对其进行 SSR 搜索,共获得 6 419 条简单序列重复（SSR）。利用 Primer 3.0 软件设计 SSR 引物,并以 11 份油梨种质筛选多态性引物。 基于转录组序列开发出的 EST-SSR 的分布频率为 17.05%。在油梨 EST-SSR 中,单核苷、二核苷和三核苷的重复占主 导,占总数的 99.07%。单、二、三核苷酸重复单元分别占总 SSR 的 37.47%、31.80%和 29.80%;出现频率最高的二核 苷酸重复基元是 AG/CT,占总数的 29.15%,出现最高的三核苷酸重复基元为 AAG/CTT,占 12.01%。随机选择 315 个 SSR 位点合成引物,经 11 份油梨种质筛选鉴定,227 对引物可扩增获得产物,有效扩增率为 72.06%;其中 34 对引物 表现出良好多态性,占有效引物的 12.78%,占总引物的 10.79%。在 34 对多态性引物中,每对引物扩增等位基因数 2~12 个。利用高通量测序开发 SSR 引物有较好的实用性,开发获得的 34 个具有多态性的油梨 SSR 标记可用于研究油梨及 其相关近缘物种的遗传变异。     

基于转录组测序的油梨 EST-SSR 引物开发

利用转录测序技术,开发油梨表达序列标签-简单重复序列（EST-SSRs）,为 SSR 标记在油梨种质资源鉴定、品种选育及遗传连锁图谱构建奠定基础。采用 Illumina 二代测序的技术,共获得 37 639 条无冗余的序列,对其进行 SSR搜索,共获得 6 419 条简单序列重复（SSR）。利用 Primer 3.0 软件设计 SSR 引物,并以 11 份油梨种质筛选多态性引物。基于转录组序列开发出的 EST-SSR 的分布频率为 17.05%。在油梨 EST-SSR 中,单核苷、二核苷和三核苷的重复占主导,占总数的 99.07%。单、二、三核苷酸重复单元分别占总 SSR 的 37.47%、31.80%和 29.80%;出现频率最高的二核苷酸重复基元是 AG/CT,占总数的 29.15%,出现最高的三核苷酸重复基元为 AAG/CTT,占 12.01%。随机选择 315 个SSR 位点合成引物,经 11 份油梨种质筛选鉴定,227 对引物可扩增获得产物,有效扩增率为 72.06%;其中 34 对引物表现出良好多态性,占有效引物的 12.78%,占总引物的 10.79%。在 34 对多态性引物中,每对引物扩增等位基因数 2~12个。利用高通量测序开发 SSR 引物有较好的实性,开发获得的 34 个具有多态性的油梨 SSR 标记可用于研究油梨及其相关近缘物种的遗传变异。     

Resistance to a highly aggressive isolate of Sclerotinia sclerotiorum in a Brassica napus diversity set

Sclerotinia stem rot (SSR) of oilseed rape (OSR, Brassica napus), caused by Sclerotinia sclerotiorum, is a serious problem in the UK and worldwide. As fungicide‐based control approaches are not always reliable, identifying host resistance is a desirable and sustainable approach to disease management. This research initially examined the aggressiveness of 18 Sclerotinia isolates (17 S. sclerotiorum, one S. subarctica) on cultivated representatives of B. rapa, B. oleracea and B. napus using a young plant test. Significant differences were observed between isolates and susceptibility of the brassica crop types, with B. rapa being the most susceptible. Sclerotinia sclerotiorum isolates from crop hosts were more aggressive than those from wild buttercup (Ranunculus acris). Sclerotinia sclerotiorum isolates P7 (pea) and DG4 (buttercup), identified as ‘aggressive’ and ‘weakly aggressive’, respectively, were used to screen 96 B. napus lines for SSR resistance in a young plant test. A subset of 20 lines was further evaluated using the same test and also in a stem inoculation test on flowering plants. A high level of SSR resistance was observed for five lines and, although there was some variability between tests, one winter OSR (line 3, Czech Republic) and one rape kale (line 83, UK) demonstrated consistent resistance. Additionally, one swede (line 69, Norway) showed an outstanding level of resistance in the stem test. Resistant lines also had fewer sclerotia forming in stems. New pre‐breeding material for the production of SSR resistant OSR cultivars relevant to conditions in the UK and Europe has therefore been identified.     

A novel screening method for rice allelopathic potential: the inhibitory‐circle method

Screening crop accessions for allelopathic activity is of paramount importance for crop allelopathy research. Previous bioassays often did not use a mixed culture of donor and target plants, did not use soil and were not conducted under natural conditions. In this study, we designed an inhibitory‐circle method in which a rice accession (donor plant) and Echinochloa crus‐galli (target plant) were cultured together in paddy soil under natural conditions. First, we determined that the highest allelopathic activity of allelopathic rice accession PI312777 was at the 5‐leaf stage, and the suitable distance of rice seedlings and E. crus‐galli was 12 cm apart. This method was then validated by a field test. A further 40 rice accessions were evaluated for allelopathic activity to E. crus‐galli using this method. Two rice accessions, PI312777 and Taichung Native 1, had highly allelopathic activity to E. crus‐galli (inhibitory rate > 50%), while another accession, Lemont, had non‐allelopathic activity. These experimental results were in accordance with previous studies using direct field experiments. The inhibitory‐circle method integrated three necessary conditions, that is donor and target plants grown together, with soil as the medium and under natural conditions for reliable results. The ‘inhibitory‐circle method’, which combined donor and target plants, soil medium and field conditions, can give reliable results in one step, compared with laboratory screening methods. Also, the ‘inhibitory‐circle method’ gave results in 30‐35 days, thereby substantially reducing the requirements for time, labour and cost.