EoNPV对茶尺蠖两近缘种的毒力差异

茶尺蠖核型多角体病毒(Ectropis obliqua nucleopolyhedrosis virus,EoNPV)是一种重要的病原微生物,为进一步明确该病毒对茶尺蠖两近缘种的毒力差异,采用叶盘法对3龄茶尺蠖和灰茶尺蠖幼虫进行了EoNPV的毒力测定。研究显示,EoNPV对灰茶尺蠖的半致死剂量LD₅₀(median lethal dose)为茶尺蠖的28.9倍,EoNPV对灰茶尺蠖的致死中时间LT₅₀(median lethal time)大于茶尺蠖。结果表明,EoNPV对茶尺蠖两近缘种间的毒力存在差异,EoNPV对茶尺蠖具有更高的致病力,研究结果对EoNPV田间防治茶尺蠖两近缘种具有现实指导意义。     

提高烟叶委托分选质量的管理措施

为确保委托方烟叶原料分选质量的稳定性，针对复烤企业承担品牌原料均质化加工要求，积极探索在管理过程中提高烟叶委托分选质量的有效途径,切实加强烟叶分选质量的全程控制，提升复烤企业为委托方品牌烟叶挑选的服务水平。     

单叶刺槐半同胞子代叶片的滞尘能力及叶表SEM特征分析

以单叶刺槐母本(A1-1)及6个叶形产生明显变异的半同胞子代无性系(A20-5、B24-3、C24-2、B23-1、C24-1、C23-1)新鲜叶片为材料,测定各样本的单位叶面积总颗粒物滞留量、颗粒物粒径分析及叶表微观结构SEM特征,通过相关性分析,筛选与滞尘能力相关的叶形及SEM指标,运用隶属函数法,依据各样本滞尘指标的隶属度均值对滞尘能力进行综合评价。结果表明:子代B23-1对空气中总颗粒物的滞留能力最强,C24-1对PM2.5的滞留能力最强,A20-5对PM2.5-10及PM>10的滞留能力最强;部分叶形及SEM特征指标与滞尘指标之间存在显著相关性;综合评价滞尘能力,全部样本可分为4类,第Ⅰ类为B23-1,滞尘能力强;第Ⅱ类为C24-1,滞尘能力较强;第Ⅲ类包括母本、A20-5、C23-1、C24-2,滞尘能力中等;第Ⅳ类为B24-3,滞尘能力相对较差。     

赣中北“油稻稻”三熟制下头季稻叶片衰老频度对再生稻再生力的影响

为研究三熟制条件下适合种植的再生稻品种及头季叶片衰老频度对再生力特性的影响,在大田试验条件下,以10个杂交水稻品种为材料,比较分析了这些品种的再生力、再生季产量及头季衰老强度等若干性状。结果表明,头季不同品种结实率与再生季再生力呈正相关关系,相关系数为0.620,头季千粒重、叶干质量下降率、叶绿素含量下降率、产量与再生季再生力呈负相关关系,相关系数分别为-0.522、-0.516、-0.637、-0.676。再生季有效穗数与再生力呈显著正相关关系,与活芽率呈负相关,相关系数分别为0.757和-0.615。头季结实率、叶片叶绿素含量、产量,以及再生季有效穗数和千粒重是影响再生力的重要因素。综合两季产量和再生力特性来看,深两优5814、C两优608、准两优608、丰两优香1号等4个品种可以作为再生稻在江西中北部的三熟制条件下种植。     

南方早熟砂梨缺镁黄叶症诊断与矫治

通过对福建省德化县早熟砂梨“黄叶病株”及“正常植株”叶片及土壤的营养诊断分析：黄叶病株叶片平均含镁量0.131%，极显著低于正常植株0.328%；黄叶症较重的果园土壤交换态镁含量低12.6～24.5㎎/㎏及土壤酸性强pH3.6～4.5，诊断结论砂梨叶片黄化现象为镁素缺乏所致。矫治试验效果，叶面喷施1%硝酸镁3次，可以叶色转绿；12月份土壤基施钙镁磷肥株1.3 kg，翌年5月份后有明显矫治效果。     

黔南州核桃优树叶片营养元素和果实品质相关分析

为了分析叶片营养元素对黔南州核桃优树坚果品质的影响,通过方差分析和相关分析研究了叶片营养元素与坚果品质之间的相关关系。结果表明:不同品种的核桃优树单株的坚果品质指标间存在显著差异;叶片钙、铜和锰显著影响核桃坚果品质。可以通过核桃叶片营养元素的诊断来提高坚果品质。     

Sensitivity of Two Quinoa (ChenopodiumquinoaWilld.) Varieties to Progressive Drought Stress

Quinoa (ChenopodiumquinoaWilld.) is a highly nutritious Andean seed crop which shows great potential to grow under a range of hostile environments. The objective of this study was to investigate the differences of drought tolerance of a Bolivian (Achachino) and a Danish (Titicaca) variety, and especially drought‐related adaption strategies. Soil water status was expressed as the fraction of transpirable soil water (FTSW). Relative stomatal conductance (RSC), relative transpiration (RT) and relative leaf water potential (RLW) were calculated by determining stomatal conductance, transpiration rate and leaf water potential of the drought‐treated plants relative to those of fully irrigated plants. The responses of RSC, RT and RLW to decreasing FTSW were described by a linear‐plateau model. The critical value of FTSW was the threshold of FTSW where the parameters studied decreased. The thresholds increased C_S for stomatal conductance, C_T for transpiration and C_Lfor leaf water potential. Achachino showed significantly lower C_T and C_L when compared with Titicaca, implying that transpiration and leaf water potential were less affected under mild drought conditions in the Bolivian variety. C_S in Achachino was significantly higher than C_L and C_T, which indicated that stomatal conductance declined before transpiration and leaf water potential were reduced. Such difference was found in Titicaca where reduction of leaf area had more effect on transpiration than stomatal closure. Slower growth rate and smaller leaf area in combination with a lower stomatal conductance was found to contribute to drought resistance in Achachino. ABA concentration in the xylem sap tended to increase in both varieties after 2 days onset of drought, prior to decline in leaf water potential. Titicaca showed significantly (P < 0.05) higher ABA concentration when compared with Achachino under both fully irrigated and drought conditions. Titicaca had higher xylem nutrient concentration in comparison with Achachino in both fully‐watered and drought plants at day 2 after onset of soil drying. It was concluded that Titicaca was more sensitive to progressive drought than Achachino which avoided water loss by means of lower growth rate and smaller leaf area.     

Present Situation and Prospect of Professional Grading and Loose-leaf Purchasing of Flue-cured Tobacco

针对目前我国烤烟专业化分级散叶收购的普遍实施。探讨了烤烟专分散收的优势，总结分析了专分散收过程中存在的问题，并针对这些问题提出了建议。以期为今后散叶收购工作的进一步推广提供实践经验。     

5个冬麦品种产量性状和叶片特征多样性分析

采用单因素完全随机设计,调查5个冬麦品种产量性状和叶片特征多样性。结果表明,5项产量相关性状指标(株高、穗长、主穗粒数、有效分蘖数、有效小穗数)在不同冬麦品种间差异均达显著水平;5个品种的上表皮气孔密度均多于下表皮,其中,上表皮气孔密度为62.67~71.11个/mm2,下表皮气孔密度为30.00~46.25个/mm2;叶脉总数为57.00~65.67条;叶脉密度为36.89~43.00条/mm。     

Temperature Before Cold Acclimation Affects Cold Tolerance and Photoacclimation in Timothy (Phleum pratense L.), Perennial Ryegrass (Lolium perenne L.) and Red Clover (Trifolium pratense L.)

The expected temperature rise in late summer/early autumn can change the conditions for acclimation and affect the winter survival of perennial crops. This study examined the effect of the temperature just before the onset of cold acclimation (pre‐acclimation) on freezing tolerance of timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.) populations (both cultivars and breeding populations) adapted to either northern or southern parts of Norway. Using phytotron experiments, we studied whether increasing pre‐acclimation temperature delays growth cessation, affects photoacclimation and reduces freezing tolerance. Furthermore, we assessed whether these effects were related to the latitudinal adaptation of the plant material. The results showed that a rise in pre‐acclimation temperature decreased both cold acclimation capacity and photoacclimation in these species. This affected the freezing tolerance, which was reduced significantly more in northern‐adapted population of timothy and perennial ryegrass compared with southern‐adapted populations. Red clover was less affected by temperature changes than the grasses.