多花黑麦草品种比较试验

对特高、富源、杰威、沃土几个牧草品种作了品比试验,测定了生育期、再生性能、营养成分、茎叶比、产草量等。生长速度:沃土(1.440 cm/d)>特高(1.386 cm/d)>杰威(1.278 cm/d)>富源(1.190 cm/d)。初花期茎叶比:特高最小(1.49),其次是杰威(1.88)、沃土(1.92),富源最大(2.27)。产量:沃土和特高分别达到4 413.6、3 920.2 kg/667m2,其次是杰威,富源在试验中产量最低,经方差分析差异达极显著水平。粗蛋白含量:富源>特高>沃土>杰威。粗脂肪含量:特高>沃土>杰威>富源。综合分析,沃土和特高是较好的品种,适宜刈割时期为抽穗前。     

新型保铃剂防治棉花烂铃的效应

应用新型保铃剂进行了防治棉花烂铃的效果试验.结果表明,在棉花生长盛期,用新型保铃剂进行多次叶面喷施,结合科学栽培管理措施,可以起到防治烂铃、增加产量的效果,与不用保铃荆的处理相比,烂铃减少13%,产量增加16%;在每公顷密度15 000株、氮肥用量450 kg的情况下,配合喷施新型保铃剂的互作效应最好,烂铃最多减少42%,产量最多增加17%.     

施用生物有机肥对云当归产量、品质及土壤养分的影响

为给云南省维西县云当归高产、优质和合理施肥提供理论依据,采用防草布覆盖开展云当归成药栽培田间试验,设置不施肥(CK1)、常规施肥(CK2)、单施化肥(C)、单施生物有机肥Ⅰ号(B_Ⅰ)、单施生物有机肥Ⅱ号(B_Ⅱ)、50%化肥+生物有机肥Ⅰ号(1/2C+B_Ⅰ)、50%化肥+生物有机肥Ⅱ号(1/2C+B_Ⅱ)7个处理,研究了不同施肥处理对云当归产量构成因素、药材产量、品质和土壤养分的影响。结果表明,(1)施用生物有机肥能促进云当归主根长、根粗、侧根数、单株鲜重、干重增加,显著提高云当归鲜、干药材产量(P<0.05),生物有机肥处理云当归鲜、干药材产量较CK1分别增产41.50%～201.13%、35.00%～69.42%,其中,1/2C+BⅠ处理鲜干产量最高,1/2C+BⅡ处理次之。(2)施用生物有机肥可提高云当归药材阿魏酸、挥发油、浸出物和多糖含量,降低总灰分含量,有效改善云当归药材品质;(3)施用生物有机肥可显著提高土壤有机质、碱解氮、有效磷和速效钾的含量(P<0.05)。施用生物有机肥处理...     

长江流域发展机采棉的现状与展望

分析了目前国际国内形势复杂变化的情况下,发展长江流域机采棉产业的现状和必要性,明确了长江流域发展机采棉的优势,分析了机采棉推广面临的问题与挑战,探讨了长江流域机采棉发展的战略。对以下几个方面提出合理化建议：长江流域机采棉发展区域化优化布局;充分利用本区域冬闲田发展小麦、油菜作物;在长江流域两湖（洞庭湖、鄱阳湖）两江（长江、汉江）近700000 hm2滩涂旱地宜棉区扩大种植棉油（麦）双直播双机采;形成以棉增油、棉油双稳的格局。     

江苏地区小麦赤霉病菌种群检测与抗药性分析

本研究旨在检测江苏地区小麦赤霉病菌的种群组成与对传统杀菌剂单剂的抗性严重度。以江苏溧阳、通州和盐城地区小麦赤霉病菌子囊孢子为试材,鉴定其优势种群,检测对多菌灵、戊唑醇和咪鲜胺的抗性。结果表明：江苏地区小麦赤霉病菌株中全部检测到亚细亚镰孢,是绝对优势种群;禾谷镰孢占比最高是溧阳地区的14%,最低是通州地区的8%,平均占比为11.33%,显著低于亚细亚镰孢占比;江苏地区小麦赤霉病菌对多菌灵的抗性频率介于26.3%~54.5%;未检测到戊唑醇和咪鲜胺具有抗性的赤霉菌株。综上,江苏地区小麦赤霉病菌优势种群是亚细亚镰孢,其对多菌灵单剂已产生严重抗性,未发现对戊唑醇和咪鲜胺产生抗性。     

Relay-intercropping soybean with maize maintains soil fertility and increases nitrogen recovery efficiency by reducing nitrogen input

Optimized nitrogen(N)management can increase N-use efficiency in intercropping systems.Legume-nonlegume intercropping systems can reduce N input by exploiting biological N fixation by legumes.Measurement of N utilization can help in dissecting the mechanisms underlying N uptake and utilization in legume-nonlegume intercropping systems.An experiment was performed with three planting patterns:monoculture maize(MM),monoculture soybean(SS),and maize-soybean relay intercropping(IMS),and three N application levels:zero N(NN),reduced N(RN),and conventional N(CN)to investigate crop N uptake and utilization characteristics.N recovery efficiency and 15N recovery rate of crops were higher under RN than under CN,and those under RN were higher under intercropping than under the corresponding monocultures.Compared with MM,IMS showed a lower soil N-dependent rate(SNDR)in 2012.However,the SNDR of MM rapidly declined from 86.8%in 2012 to 49.4%in 2014,whereas that of IMS declined slowly from 75.4%in 2012 to 69.4%in 2014.The interspecific N competition rate(NCRms)was higher under RN than under CN,and increased yearly.Soybean nodule dry weight and nitrogenase activities were respectively 34.2%and 12.5%higher under intercropping than in monoculture at the beginning seed stage.The amount(Ndfa)and ratio(%Ndfa)of soybean N2 fixation were significantly greater under IS than under SS.In conclusion,N fertilizer was more efficiently used under RN than under CN;in particular,the relay intercropping system promoted N fertilizer utilization in comparison with the corresponding monocultures.An intercropping system helps to maintain soil fertility because interspecific N competition promotes biological N fixation by soybean by reducing N input.Thus,a maize-soybean relay intercropping system with reduced N application is sustainable and environmentally friendly.     

Genetic bases of source-,sink-,and yield-related traits revealed by genome-wide association study in Xian rice

The source-sink relationship determines the ultimate grain yield.We investigated the genetic basis of the relationship between source and sink and yield potential in rice.In two environments,we identified quantitative trait loci(QTL)associated with sink capacity(total spikelet number per panicle and thousand-grain weight),source leaf(flag leaf length,flag leaf width and flag leaf area),source-sink relationship(total spikelet number to flag leaf area ratio)and yield-related traits(filled grain number per panicle,panicle number per plant,grain yield per plant,biomass per plant,and harvest index)by genome-wide association analysis using 272 Xian(indica)accessions.The panel showed substantial variation for all traits in the two environments and revealed complex phenotypic correlations.A total of 70 QTL influencing the 11 traits were identified using 469,377 high-quality SNP markers.Five QTL were detected consistently in four chromosomal regions in both environments.Five QTL clusters simultaneously affected source,sink,source–sink relationship,and grain yield traits,probably explaining the genetic basis of significant correlations of grain yield with source and sink traits.We selected 24 candidate genes in the four consistent QTL regions by identifying linkage disequilibrium(LD)blocks associated with significant SNPs and performing haplotype analysis.The genes included one cloned gene(NOG1)and three newly identified QTL(qHI6,qTGW7,and qFLA8).These results provide a theoretical basis for high-yield rice breeding by increasing and balancing source–sink relationships using marker-assisted selection.     

柑桔黄龙病三种媒介昆虫的研究进展

柑桔木虱是传播世界毁灭性病害柑桔黄龙病的唯一虫媒,因此,科学合理防治柑桔木虱是治理柑桔黄龙病的关键措施之一。本文系统概述了柑桔上3种木虱的生物学特性、发生和扩散规律、与柑桔黄龙病的互作及传毒机制等方面的研究进展,以期为柑桔木虱的合理防治提供参考,为柑桔黄龙病的综合治理提供理论依据和借鉴。