Screening and identification of soybean varieties with high phosphorus efficiency at seedling stage

In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X₁),relative value of root P utilization efficiency(X₂),and root volume(X₃)under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X₁t 0.320X₂t 0.007X₃-0.664(P=0.000,R²=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.     

农村互联网发展对中国玉米全要素生产率的影响

采用DEA-mamlquist指数测算2004—2019年中国17个玉米主产省(区)的全要素生产率,运用联立方程组模型实证检验农村互联网发展对玉米全要素生产率的影响及其作用机理,并分区域探讨其差异性。结果显示:2004—2019年中国玉米全要素生产率年均增长0.2%,主要依靠技术进步的单轨模式驱动。农村互联网的发展显著(P<0.01)提升玉米全要素生产率,主要依靠技术进步和技术效率的协同作用驱动。分区域来看,农村互联网发展对玉米全要素生产率均具有显著(P<0.01)的促进作用,其影响程度由高到低依次为北方春播玉米区>黄淮海平原夏播玉米区>西北灌溉玉米区>西南山地玉米区。建议进一步提高农村互联网的配套设施建设,发挥互联网“连接经济”的优势,应用多元化互联网技术,促进不同生态类型区玉米生产效率的提升。     

茶树叶部害虫——茶橙瘿螨

茶橙瘿螨是茶树上一种常见害螨,以成螨、幼螨和若螨刺吸茶树汁液为害茶树,减弱树势,对茶叶产量和品质产生影响。文章介绍了茶橙瘿螨的分布与为害、形态特征、发生规律和防治措施,以期为生产上该害虫的正确识别和有效防治提供参考。     

我国黄瓜抗病品种选育技术研究进展

黄瓜在我国蔬菜产业中占有重要地位,然而连片种植、重茬栽培等条件下容易滋生病菌,尤其是随着我国保护地蔬菜生产规模的扩大,棚室内的温湿度条件更利于病害的发生与流行,黄瓜生产上面临着严重的病虫害威胁,包括生理性病害、感染性病害及虫害等。本文从抗病品种选育的角度分析了黄瓜病害抗病品种选育技术,并简要介绍了其他防治方法,展望了相关研究的发展方向,为黄瓜病虫害的防治提供参考。     

父母本不同行距配置对昆虫授粉效率的影响

为探讨昆虫为杂交大豆授粉的行为,提高授粉效率,以大豆细胞质雄性不育系JLCMS34A和保持系JLCMS34B为材料,研究父母本3种行距配置(T1、T2、T3)对昆虫授粉行为及产量构成的影响。结果表明:行距配置T2条件下昆虫授粉效率最高,母本单株粒数最多,为45.98个(2011年),与T1、T3差异达到显著水平,T3配置授粉效率最差,单株粒数最少,为32.06个(2012年),与T1、T2差异达到极显著水平。在吉林省洮南地区适当缩小父母本行距,增加母本间行距可有效促进昆虫授粉效率,提高结实率。     

沉淀法制备的紫杉醇白蛋白微粒包封率测定

采用沉淀法制备紫杉醇白蛋白微粒,采用高效液相色谱法(HPLC)测定紫杉醇质量浓度,以二氯甲烷为有机相,采用萃取法分离白蛋白微粒与游离药物,测定其包封率。结果表明:紫杉醇在10~100 mg·L-1范围内线性良好,平均回收率可达到97.6%~101.0%;有机溶剂萃取法测定紫杉醇白蛋白微粒包封率的平均回收率,达94.80%~101.67%。这种方法测定紫杉醇白蛋白微粒回收率准确可靠,适用于沉淀法制备的白蛋白微粒的包封率测定。     

规模化猪舍废气复合净化系统设计与试验

为解决规模化猪舍废气排放造成的环境污染问题，设计了一种猪舍废气复合净化系统。该系统采用化学法与水洗法相结合，通过PLC（可编程逻辑控制器）控制系统实时采集净化系统内的pH值、电导率、液位和压差等动态环境数据，智能控制洗涤泵启停和电磁阀通断，自动完成供水、加酸、喷淋和排废4个工作环节。同时，控制系统采用MCGS触摸屏与PLC建立通讯，通过创建人机交互界面实现系统环境数据监测、运行状态流动显示、按需配置系统参数和报警信息输出等多种功能，实现了系统操作的人性化和过程的可视化。系统可根据实际应用中对净化效率和运行成本的要求，实现多种控制模式，均有效抑制了猪舍废气排放。试验结果表明，系统对主要污染成分氨气的平均去除率可达到85%，整体运行可靠、控制简单，经济成本量化清晰。该系统在江西某种猪场实施应用，成效显著，可为畜禽养殖环境废气净化处理的工程应用提供参考。     

Ray blight of pyrethrum in Australia: a review of the current status and future opportunities

Ray blight caused by Stagonosporopsis tanaceti is one of the most important diseases of pyrethrum (Tanacetum cinerariifolium), a perennial herbaceous plant cultivated for the extraction of insecticidal pyrethrins in Australia. The disease is responsible for complete yield loss in severe outbreaks. Infected seed is considered as the principal source of S. tanaceti. Infection hyphae remain only in the seed coat and not in the embryo, resulting in pre- and post-emergence death of seedlings and latent infection. Therefore, quantification of the level of infection by S. tanaceti within seed using a qPCR assay is important for efficient management of the disease. Stagonosporopsis tanaceti completes its life cycle within 12 days after leaf infection through production of pycnidia and can infect every tissue of the pyrethrum plant except the vascular and root tissues. Ray blight epidemics occur in pyrethrum fields through splash dispersal of pycnidiospores between adjacent plants. Besides steam sterilization, thiabendazole/thiram and fludioxonil are effective seed-treating chemicals in controlling S. tanaceti before planting begins. Ray blight is currently managed in the field through the foliar application of strobilurin fungicides in the first 1–2 years of crop establishment. Later on, difenoconazole and multisite specific fungicides in the next 2–3 years during early spring successfully reduce ray blight infestation. Avoiding development of resistance to fungicides will require more sustainable management of ray blight including the development and deployment of resistant cultivars.     

水分与氮素及其互作对水稻产量和水肥利用效率的影响研究进展

了解水分、氮素及其互作对水稻产量与水、氮利用效率的影响,对协同提高水稻产量与水氮利用效率有重要意义。本文概述了水稻节水灌溉技术、氮肥利用效率与氮肥施用技术、水分与氮素对水稻产量及水氮利用效率的耦合效应、作物-土壤关系及水氮调控机制等方面取得的进展;讨论了存在的问题,这些问题包括:高产水稻作物与土壤的水氮互作效应尚不明确;高产水稻水氮耦合与高效利用的分子机理不清楚;协同提高水稻产量与水氮利用效率的调控途径尚未掌握。针对这些问题,建议今后重点研究:高产水稻作物与土壤的水氮互作效应及其机制;水氮互作调控水稻吸收利用水分和氮素的生理与分子机理;协同提高水稻产量和水氮利用效率的调控途径与关键技术。     

上海水稻精量机械穴直播技术研究与应用

以上海地区主推水稻品种为材料,在精量机械穴直播条件下,开展了不同类型水稻品种的小区试验和示范,明确了精量机械穴直播水稻的生育特性、抗倒伏性、群体建成和产量表现,并分析了采用水稻精量机械穴直播后土壤的微生物群落结构的变化和水稻生产经济效益。试验示范结果表明,精量机械穴直播水稻生育期明显缩短,单株分蘖力强,群体结构合理,穗粒结构协调,干物质积累多,抗倒能力较强,增产优势明显,节本低耗,生产效率显著提高,是目前极具生产潜力的一种新型高效低耗种植模式,适合上海都市农业发展的需求,也顺应了水稻低碳种植发展趋势,具有广阔的应用前景。