发酵饼肥对烤烟各器官磷积累和分配的影响

采用田间小区试验设计,研究了定向发酵饼肥不同施用比例对烤烟磷积累和分配的影响。结果表明,根系磷积累表现为先升高后降低的变化,50%饼肥处理与对照之间无显著差异;茎磷积累量3个处理之间无显著差异;烟叶内磷积累呈现出一直升高的变化,下部叶和上部叶3个处理之间无显著差异,中部叶50%饼肥处理与对照之间无显著差异;不同饼肥施用比例不会改变磷在不同部位烟叶中积累的基本规律。综合分析认为,定向发酵饼肥施用比例在50%情况下不会显著改变磷积累和分配的规律,为较好的施用比例。     

重金属低积累玉米品种的稳定性和环境适应性分析

选择当地大面积推广的5个玉米品种:正红311(1)、成单30(2)、川单428(3)、隆单8(4)和川单418(5),种植于四川射洪县玉米示范区的7个试点,通过AMMI模型研究品种和环境交互效应对玉米籽粒积累重金属能力的影响,旨在获得对重金属吸收具有低积累性和环境适应性较好的玉米品种。结果表明,Cu的品种效应(SS,平方和)占总效应的77.6%,玉米籽粒低积累Cu的性状有很高的重现性;而As、Hg、Pb、Zn、Cr5种重金属元素品种与环境交互效应同品种、环境效应比较占主导作用,分别为63.4%、74.3%、50.3%、69.2%和57.5%。通过双标图分析,比较了不同玉米品种籽粒富集重金属能力的大小和稳定顺序。AMMI模型为研究品种×地点交互效应对作物积累重金属能力的影响和评价品种稳定性提供了较好的分析方法,对于低重金属积累品种的准确筛选和成功应用具有重要意义。     

基于文献计量的荒漠灌丛研究现状及热点分析

以中国期刊全文数据库(CNKI)和Web of science数据库中与荒漠灌丛有关的文献为国内和国际文献基础数据源,利用Origin 2019按年份统计发文量、论文增长率和文献共被引次数,通过Bibexcel将筛选出的高频关键词生成共词矩阵,利用Ucinet和Netdraw等软件得出高频关键词共现网络化可视图.利用S...     

影响套袋梨果面光洁度的因素及防止措施

近年来，我市栽培的黄金、大果水晶、新世纪、金二十世纪、绿宝石等梨品种，果实普遍套袋。但果实出现果锈、皲皮、裂口、黑斑、黑点等现象，影响了果面光洁度，降低了商品率，制约了出口，造成很大损失。为究其原因，笔者进行了调查，明确了影响果面光洁度的因素，并采取了相应的措施，使优质果率由原来的78％提高到89％。     

荔枝草农用活性初步研究

研究了荔枝草乙醇提取物及其萃取物的抑菌、除草活性。结果表明,荔枝草乙醇提取物对27种供试病原真菌均有一定抑制作用。乙醇提取物在浓度为0．03g／mL（以干材料计）时,对苹果腐烂病菌、葡萄白腐病菌、瓜果腐霉病菌的抑制率分别达到89．09％、91．12％、92．59％;荔枝草乙醇提取物的乙酸乙酯萃取物对苹果腐烂病菌、葡萄白腐病菌、瓜果腐霉病菌抑制效果最好,其EC50分别为0．24、0．29、0.12mg/mL;荔枝草乙醇提取物对几种杂草也有很好的抑制效果,在浓度为0．2g／mL时,对生菜、反枝苋、黄瓜的抑制率分别为93．65％、92．76％和97．57％。     

黄河三角洲外来入侵有害生物的初步研究

经过实地调查和资料分析,初步确定黄河三角洲外来入侵有害生物物种达70种,其中外来入侵有害动物15种、有害病原微生物7种、有害植物48种。在此基础上,明确了这些外来入侵物种的地理分布,并提出了相应的防治对策。     

30年生不同生长势杉木的胸径和树高的生长动态

采用树干解析法获取3种不同生长势（优势木、中庸木、被压木）杉木的胸径、树高生长数据,利用ForStat的生长曲线模拟杉木的胸径模型和树高模型,结果表明,Richards生长曲线是分析杉木胸径和树高的适宜生长曲线;3种不同生长势的杉木胸径生长曲线和树高生长曲线均呈“S”状曲线,有较高的相关性。     

Detection and Analysis of Magnaporthe oryzae Avirulence Genes AVR-Pib,AVR-Pik and AvrPiz-t in Heilongjiang Province

【Objective】The objective of this study is to investigate the distribution and variation mechanism of avirulence genes AVR-Pib, AVR-Pik and AvrPiz-t in Magnaporthe oryzae strains from different regions and years in Heilongjiang Province, to understand the pathogenic phenotypes of different avirulence gene alleles, and to provide a reference for utilization and distribution of resistance cultivars in Heilongjiang Province.【Method】Based on the avirulence gene sequences published in NCBI, specific primers were designed to amplify full length and the coding sequence (CDS) regions of three genes, respectively. From 2016 to 2017, 335 M. oryzae strains in different regions of Heilongjiang Province were collected and isolated, and their DNA was PCR-amplified using avirulence genes primers and analyzed by agarose gel electrophoresis. The PCR products with different band patterns and from representative strains of different regions were selected for sequencing. The sequencing results were compared with the corresponding avirulence gene sequences for base and amino acid. The pathogenic phenotype of M. oryzae strains with different variant types was determined based on the rice resistance to single-gene lines.【Result】The specific bands of AVR-Pib, AVR-Pik and AvrPiz-t were detected in PCR detection and appeared in different distribution frequencies and mutation types, indicating that these 3 avirulence genes were all distributed in Heilongjiang Province. The average amplification frequency of the 3 avirulence genes was 75.52%, 87.16% and 85.67%, respectively. Among them, 4 types of band (bandless, high band, mid to high band and low band) of AVR-Pib were detected by electrophoresis analysis and 5 variant types AVR-Pib (1-1, 1-2, 2, 3, 3-1) were detected by PCR product sequencing. The genotypes AVR-Pib-1-1, AVR-Pib-1-2, AVR-Pib-2 and AVR-Pib-3-1 are newly discovered variant types, of which genotypes AVR-Pib-1-1 and AVR-Pib-1-2 are insertions of transposon Pot2 but with different insertion sites. The genotype AVR-Pib-2 has a small fragment insertion in the upstream of CDS region. The genotype AVR-Pib-3-1 base sequence has 4 differences from the original sequence, namely 32 (C/G) 35 (T/A) 36 (T/A) 38 (T/A), and the amino acid translation was terminated prematurely. Pathogenic analysis showed that except for the normal genotype AVR-Pib-3, the other alleles lost their avirulence functions. Seven AVR-Pik alleles (D, A, B, C, E, F, F2) were detected after PCR product sequencing, and the alterations in the nucleotide sequences of these alleles all resulted in amino acid missense mutations. The 7 AVR-Pik alleles have been reported previously. The avirulence gene AvrPiz-t was analyzed by electrophoresis and sequencing of PCR products, and 2 types of band (high band and normal band type) and 4 genotypes of AvrPiz-t (A, B, C, D) were revealed. Among them, AvrPiz-t-A is the original genotype, while AvrPiz-t-B has a base A insertion at position 191, causing premature termination of amino acid translation. Genotype AvrPiz-t-C is a newly discovered allelic type, characterized by the presence of a nucleotide variation at position 17 (T/C) and the insertion of base C at position 19 compared with type A, leading to the frameshift mutation and premature translation termination. The high band type avirulent genotype AvrPiz-t-D was sequenced and verified as having an insertion of the Pot3 transposon. Rice single-gene lines infection showed that the strains with AvrPiz-t-A were avirulent to Piz-t line due to Piz-t recognition, whereas the strains with AvrPiz-t (B, C, D) were virulent to Piz-t line due to lost the ability recognized by Piz-t.【Conclusion】The avirulence genes AVR-Pib, AVR-Pik and AvrPiz-t of M. oryzae in Heilongjiang Province are widely distributed and the types of variation are abundant. The results of this study can provide a reference for breeding and popularizing rice cultivars with corresponding disease-resistance genes.     

喷灌定额和灌水频次对冬小麦产量及品质的影响分析

为了解圆形喷灌机不同灌溉定额和灌水频次对冬小麦产量及籽粒品质的影响,于2014—2016年在北京市顺义区进行了水肥一体化大田试验,共设置3种灌水处理(W1、W2、W3),其中2014—2015年灌溉定额分别为135、112.5、90 mm,2015—2016年分别为154.5、132、109.5 mm。每种处理在冬小麦的返青-拔节、拔节-抽穗和抽穗-灌浆期土壤含水率分别达到田间持水量的70%、75%和75%时进行灌水。每个生育时期又按灌水定额设置为1次灌水(C1)和均分成2次灌水(C2),其中C2处理2次灌水时间间隔为9 d。试验结果表明,冬小麦拔节-抽穗期的阶段耗水量和日均耗水量均最大,W1处理产量最高。2015—2016年灌溉定额与灌水频次对水分利用效率的影响均不显著,但水分利用效率有随灌溉定额增加而降低的趋势,最大水分利用效率为W3处理的2.28 kg/m3。在W1和W2处理下,分2次灌水有利于提高冬小麦的穗数、产量和容重等指标,其中W1C2组合获得最高产量9 286.4 kg/hm2。灌溉定额与灌水频次组合对产量的效应中,灌溉定额起主导作用。建议北京地区冬小麦在圆形喷灌机条件下采用W1C2灌水方案,在返青-拔节、拔节-抽穗、抽穗-灌浆期分别灌水45、55.5、54 mm,且均分成2次灌水。     

30％已·乙水剂对玉米产量和茎秆质量的影响

30%已.乙水剂处理极显著缩短穗下部节间长度,降低了植株和果穗的重心,提高了子粒形成期和灌浆期穗下部节间单位长度干重,极显著提高穗下部节间折断时的最大载荷和径向的碾碎强度,增加了穗下各茎节的粗度,总体提高玉米茎的抗倒伏性能。同时,化控处理降低了空秆率和秃尖长,提高了行粒数和穗粒重,显著提高了产量,化控措施使玉米子粒产量与茎秆质量得到了协同改善。