一株茶树冰核细菌拮抗菌的筛选及鉴定

从茶园土壤中分离出菌株TS1,通过含菌平板测定,确定其对茶树冰核细菌具有拮抗作用。通过菌株的形态特征观察、生理生化指标测定、16 S rDNA序列测定及序列同源性分析,将TS1菌株鉴定为枯草芽孢杆菌(Bacillus subtilis)。明确了拮抗菌的种属,为茶树霜冻害的生物防治奠定了基础。     

向日葵列当的内生细菌分离筛选与初步鉴定

为获得对向日葵菌核病有较强生防效果的拮抗细菌,从向日葵根部一年生全寄生杂草向日葵列当植株内分离纯化得到135株内生细菌菌株。依次采用平板对峙法、生长速率法、离体叶片防效试验、菌核萌发抑制试验筛选得到2株对核盘菌拮抗活性较好的内生细菌LIEH 92和LIEB54,用内生拮抗细菌菌株发酵液无菌滤液进行离体叶片防效试验发现,2个菌株的离体防效分别达68.48%和62.33%;LIEH 92和LIEB 54滤液处理过的菌核均不萌发,在防治向日葵菌核病方面具有良好的生防潜力。除木糖利用和V.P试验(Vopes-prokauer test)外,菌株LIEH 92与粘质沙雷氏菌的生理生化特征一致。16S r DNA序列分析鉴定,与菌株LIEH 92相似性大于99%的菌株归于肠杆菌科的沙雷氏菌属。以16S r DNA序列为基础构建系统发育树,发现菌株LIEH 92与各粘质沙雷氏菌同源性最高,因此认为菌株LIEH 92可能为粘质沙雷氏菌(Serratia marcescens)的新亚种。     

一株产铁载体橡胶树拮抗细菌的分离鉴定及耐药性分析

从橡胶树根部分离到一株拮抗细菌Czk1,该菌株在铬天青(CAS)检测平板上产生较大的桔黄色显色圈,具较强的铁载体产生能力.对其进行生理生化鉴定、16S rDNA序列分析,测定7种常见抗生素的抗性.结合该菌菌落、菌体特征,生理生化指标及16S rDNA序列分析,鉴定该内生菌为枯草芽孢杆菌(Bacillus subtilis),该菌对四环素、红霉素、氨苄青霉素、利福平、链霉素和卡那霉素高度敏感,对氯霉素表现抗性.     

香蕉嗜铁内生细菌BEB99的分离鉴定及其抗病促生能力评价

从健康的香蕉根组织内分离获得一株对香蕉枯萎病菌（Fusarium oxysporum f.sp. cubense）有拮抗作用的内生细菌菌株BEB99，经形态学、生理生化特征及16S rDNA序列同源性分析等方面的研究，鉴定该菌为劳尔氏菌（Ralstonia sp.）。铁载体检测结果发现，该菌株属于极高产铁载体菌株。盆栽试验结果表明，该菌株对香蕉枯萎病的防治效果达62.52％，并对香蕉植株具有显著的促生作用。     

砂生槐根瘤内抗小麦纹枯病生防菌株的筛选及其鉴定

为了筛选对小麦纹枯病菌具有生防作用的菌株,从西藏米林县采集的砂生槐根瘤中分离到45株内生细菌,采用平板对峙法、菌丝生长速率法进行拮抗菌株筛选,用显微观察法研究受抑制病原菌菌丝变化;通过摇瓶培养法测定所筛选拮抗菌株的溶磷、固氮及分泌IAA功能,并对其进行盆栽接种防效试验;依据形态观察、生理生化反应及16S rDNA序列同源性分析确定所筛选菌株系统发育地位。结果表明,经过初筛和复筛,45株内生菌中,菌株R4对小麦纹枯病菌的拮抗效果较明显,对其抑菌圈直径达20.5 mm,抑菌率达98.2%,显著推迟菌核的萌发。受R4作用的小麦纹枯病菌菌丝末端分枝增多、部分原生质浓缩、形成瘤状结。菌株R4抗菌谱广,具有溶磷、固氮和分泌IAA活性。盆栽防效试验中,经菌株R4发酵液处理后,小麦纹枯病发病率和病情指数均显著降低,防治效果最高达73.82%。通过形态、生理生化特性及16S rDNA基因序列同源性比对分析,该菌株被鉴定为土地类芽孢杆菌Paenibacillus terrae。     

抗茶树冰核细菌内生菌的筛选及鉴定

从茶树内生菌中进行了冰核细菌拮抗菌的筛选,得到菌株Y1,通过对菌株Y1进行形态学观察、生理生化指标测定及16βS rDNA序列测定和序列同源性分析,将菌株Y1鉴定为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。本研究获得了茶树内生拮抗菌株,明确了菌株Y1的种属,有利于冰核细菌生物防治的开展。     

玉米茎腐病病原禾谷镰孢拮抗菌筛选及分子鉴定

禾谷镰孢引起的玉米茎腐病会导致玉米产量锐减,筛选高效的拮抗菌株对防治玉米茎腐病尤为重要。采用稀释培养法从土壤中分离得到810株细菌,通过平板对峙法和16S rDNA分子测序方法进行拮抗菌的筛选和分子鉴定,共分离出禾谷镰孢拮抗菌23株,占分离细菌总数的2.84%,抑菌圈直径10.12～27.56 mm。拮抗细菌主要分布在厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和放线菌门(Actinobacteria)3个门及芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、链霉菌属(Streptomyces)、不动杆菌属(Acinetobacter)和节杆菌属(Arthrobacter)5个属中,其中,芽孢杆菌属细菌数量最多且拮抗能力较强,暹罗芽孢杆菌(Bacillus siamensis)的拮抗活性最强,具有较大的生防潜力。实验分离的23株菌株对禾谷镰孢有较好的拮抗活性,在玉米茎腐病防控中具有潜在的应用价值。     

甘蔗黑穗病菌拮抗菌HAS的筛选和鉴定

采用传统形态学鉴定及16S rRNA基因序列分析,筛选鉴定对甘蔗黑穗病菌具有拮抗作用的细菌的归属,并采用细菌的通用引物P0、P6扩增16S rRNA基因片段.结果表明:得到1 533 bp的DNA片段,其序列与枯草芽孢杆菌序列的同源性高达99％.其形态学特征:菌体为短杆状,能运动；革兰氏阳性反应；3％KOH溶解性实验呈阴性反应；有鞭毛,鞭毛周生；芽孢中生,椭圆形,孢囊稍膨大,初步将该菌株归属为枯草芽孢杆菌.与病原真菌对峙培养的结果表明,该菌对引起甘蔗和其它作物病害的多个植物病原真菌均具有很好的抑制作用.据此,可将分离的菌株HAS确定为对甘蔗黑穗病菌有较好防治效果的枯草芽孢杆菌.     

拮抗线虫的花生根瘤内生细菌筛选及鉴定

用拮抗内生细菌控制根结线虫具有重要意义。于全国范围内选择不同生境的地块采集土样,室内诱集花生根瘤,获得了丰富的根瘤内生细菌种群。利用半根瘤法从花生根瘤中分离内生细菌,以北方根结线虫为靶标,筛选其中对根结线虫二龄幼虫具有高毒力的内生细菌菌株。在诱集获得的637个根瘤样本中,有19个处理二龄幼虫致死率达80%以上的高效根瘤样本,其中2个根瘤样本处理24h时致死率可达94%。通过对19个根瘤样本的内生菌进行分离纯化,获得123株内生菌,通过对其发酵液杀线虫活性进行研究获得活性较高的9个菌株,其中Sneb1706处理二龄幼虫24h致死率达到91.4%,Sneb1872对卵的孵化抑制率可达到59.4%,Sneb1773对植物表现出明显的促生作用。经16S RNA序列分析和生理生化鉴定,这9个高杀线虫活性的根瘤内生菌菌株属于假单胞菌属(Pseudomonas)、寡氧单胞属(Stenotrophomonas)和根瘤菌属(Rhizobium)。     

引发小麦赤霉病和茎基腐病禾谷镰孢菌的生物防治初探

禾谷镰孢菌(Fusarium graminearum)是小麦上的重要病原真菌。通过致病性测定从江苏小麦茎基腐病病害样本分离菌中筛选到了对小麦赤霉病和茎基腐病都有强致病力的F.graminearum菌株GF1117。为了对F.graminearum进行生物防治,利用稀释涂布平板法和平板对峙法从小麦不同生境中分离筛选到35株对GF1117具有明显拮抗效果的细菌菌株,分别在田间和温室进行了小麦赤霉病和茎基腐病的生物防治试验。结果表明,35株拮抗细菌对小麦赤霉病均有一定的防治效果,且在小麦感病品种和中抗品种上对茎基腐病的防效不同;菌株1-8对两种病害的防效都在45%以上。     

Effects of short periods of chilling and warming on potato sugar content and chipping quality

Two days of chilling (exposure to 1 C) had no detectable effect on chip color or sugar content of potato (Solanum tuberosum L.) tubers. Four days of chilling led to increases in sugars if potatoes were stored at 10 C or 19 C for 3 to 4 days after chilling ended. Longer chilling gave increases in sugars by the end of the chilling period, and returning tubers to 10 C or 19 C magnified the response. Glucose and fructose gave similar increases from chilling treatments, except that glucose levels were consistently greater. Sucrose was increased by chilling, but the response pattern did not always resemble that of the reducing sugars. Twenty-seven days of storage at 19 C after chilling lowered levels of reducing sugars late in the storage season but not in December. Cultivars differed in response to chilling. Kennebec tubers accumulated far more reducing sugars but much less sucrose than did Norchip tubers. Storage at 19 C after chilling lowered the sucrose content of Kennebec and Monona while raising that of Norchip.     

Germination of Astragalus hamosus L. and Coronilla scorpioides (L.) as influenced by temperature

Seed germination of two pasture legumes was tested under dark conditions at three alternating temperatures of 5-20, 15-20, 20-35 degrees C and constant 20 degrees C. Duration of the alternating temperatures was 12 h. The seedling counts were checked every day during four weeks. Species differed significantly in germination response to temperature. A. hamosus was more sensitive to temperature than C. scorpioides. The temperature of 20-35 degrees C was more favourable for the germination of A. hamosus than constant 20 degrees C which markedly reduced its germination. The interaction between accessions and temperatures for total germination was significant in both species. In A. hamosus, almost 50% of germination was achieved by all accessions by the first week at alternating 20-35 degrees C temperature while in C. scorpioides, average total germination was significantly low (4%) even by the 28th day. A total rate of 11 and 9% of germination were recorded by two accessions from Ouesslatia (210) and Agareb (19), respectively. A considerable variation for germination was observed among accessions of both species. Temperature requirements for seed germination of the studied species suggest why they are relatively easy or difficult to establish in the field. A. hamosus, with very small seeds required relatively high alternating temperature for germination than C. scorpioides which was insensitive to temperature and has relatively bigger seeds.     

外源海藻糖对高温胁迫小麦干物质积累和籽粒灌浆的影响

为明确海藻糖喷施时期及浓度对高温胁迫小麦产量形成的影响,于2020—2021年度以扬麦18、烟农19为供试品种,设置三个海藻糖浓度5 mmol·L^-1（C1）、10 mmol·L^-1（C2）、15 mmol·L^-1（C3）,分别在抽穗期（T1）、开花期（T2）、花后10 d（T3）喷施海藻糖,以喷施等量清水为对照,花后15~19 d进行高温胁迫,分析不同处理对小麦干物质积累、分配和产量的影响。结果表明,T1时期喷施海藻糖较T3和T2时期产量增加了0.64%和2.54%。C3浓度处理较C2和C1浓度处理产量提升了2.35%和10.30%;T1时期喷施C3浓度海藻糖小麦产量最高,与对照相比烟农19产量增加了15.87%,扬麦18产量增加了17.75%。T1处理下籽粒干物质分配比例较T2、T3处理分别高0.24%和0.15%,C3处理较C1、C2处理分别增加了3.07%和0.82%;海藻糖处理较对照提高了营养器官中干物质向籽粒的转运量,提升了高温胁迫下小麦干物质积累速率、小麦籽粒平均灌浆速率、有效灌浆时长、最大灌浆速率,延缓了最大灌浆速率出现时间。这说明海藻糖处理能够提高小麦的耐高温性,海藻糖喷施浓度比喷施时期对小麦产量的影响更大。本试验条件下,T1时期喷施C3浓度海藻糖产量最高。     

Competition among seedlings of phalaris, subterranean clover and white clover in diallel replacement series mixtures

Phalaris, subterranean clover and white clover were grown together in binary, diallel replacement series mixtures at (day/night) 15/10 or 24/19°C under long-day conditions, and cut at 2- or 4-weekly intervals. Analysis of white clover mixtures was confined to 15/10°C due to losses of seedlings prior to imposition of treatments at 24/19°C.
With white clover at 15/10°X, seedling losses occurred after the first harvest, the greater losses occurring in mixtures where subterranean clover was the major component. The de Wit analyses showed that subterranean clover excluded its companions, whereas phalaris and white clover competed for slightly different niches resulting in over-yielding. Gleeson McGilchrist analyses showed that subterranean clover and phalaris were more aggressive than white clover under infrequent cutting, but that white clover was more aggressive as a major than as a minor component of a mixture under frequent cutting. Between phalaris and subterranean clover [he pattern of competition at 24/19°C differed from that at 15/10°C only in the more rapid development of subterranean clover and consequent swing to phalaris dominance.
We conclude that the seedlings of white clover and subterranean clover are suited to combination with phalaris because phalaris is not too aggressive towards white clover, and is tolerant of the aggressiveness of subterranean clover. The survival of only a few seedlings of white clover in mixtures with subterranean clover may be sufficient for long-term growth provided some perennation occurs after the senescence of subterranean clover.     

ENVIRONMENTAL EFFECTS ON SYMPTOM EXPRESSIONS OF VIRUS DISEASES IN GRASSES

Viruss damage was observed on plants of Lolium perenne L. and Dactylis glomcrata L. undergoing growth-analysis studies. On the basis of visual symptoms the damage was presumed to be caused by barley-yellow-dwarf virus (BYDV) in ryegrass and by streak virus (CSV) in cocksfoot. The number of plants which could be clinically diagnosed as infected and the degree of damage were both positively correlated with temperature. It was inferred that at low temperatures both viruses could remain relatively inactive, or even latent. This was subsequently confirmed by removing cocksfoot plants from a heated glasshouse (19°–23°C) to a cold environment (6–10°C) which resulted in a progressive loss of symptoms in newly developing leaves. Some possible explanations and practical implications are briefly discussed.     

Fatty acid methyl ester from Neurospora intermedia N-1 isolated from Indonesian red peanut cake (oncom merah)

The objective of this study was to identify the Fatty Acid Methyl Ester (FAME) from Neurospora intermedia N-1 that isolated from Indonesian red peanut cake (oncom). FAME profiles have been used as biochemical characters to study many different groups of organisms, such as bacteria and yeasts. FAME from N. intermedia N-1 was obtained by some stages of extraction the orange spores and fractination using a chromatotron. The pure compound (1) was characterized by 500 mHz NMR (1H and 13C), FTIR and LC-MS. Summarized data's of 1H and 13C NMR spectra of compound 1 contained 19 Carbon, 34 Hydrogen and 2 Oxygen (C19H34O2). The position of the double bonds at carbon number 8 and 12 were indicated in the HMBC spectrum (2D-NMR). LC-MS spectrum indicates molecular weight of the compound 1 as 294 which is visible by the presence of protonated molecular ion [M+H] at m/z 295. Methyl esters of long chain fatty acids was presented by a 3 band pattern of IR spectrum with bands near 1249, 1199 and 1172 cm(-1). We suggested that the structure of the pure compound 1 is methyl octadeca-8,12-dienoate. The presence methyl octadeca-8,12-dienoate in N. intermedia is the first report.     

山东省八九十年代玉米杂种优势模式的利用

通过对山东省 1 980～ 1 999年生产上推广的 37个主要玉米杂交种进行分析 ,总结探索出山东省八九十年代有 1 0种杂种优势主体模式和 1 9种子模式。其中 ,应用最多的主体模式为BSSS群×唐四平头群 ,子模式为 81 1 2亚群×唐四平头群、XL80亚群×唐四平头群和C1 0 3亚群×唐四平头群     

马铃薯新品种晋薯19号的选育

晋薯19号新品种是山西省农科院高寒区作物研究所1999年以9665-7作母本,晋薯7号作父本,有性杂交获得实生籽,经过各代鉴定筛选而育成。该品种2006～2008年参加山西省马铃薯区域试验,2008年同时参加省生产试验,2009年通过田间鉴定。2010年5月通过山西省农作物品种审定委员会审定。薯块干物质含量19.0%,淀粉含量16.0%,还原糖含量0.29%,维生素C含量19.0 mg/100 g鲜薯,田间抗晚疫病。     

瓜实蝇气味结合蛋白基因的克隆及表达谱分析

在气味识别过程中,气味结合蛋白(OBPs)对昆虫的行为反应有重要作用。通过转录组库和NCBI筛选获得瓜实蝇[Bactrocera cucurbitae(Coquillett)]OBPs基因序列,进而通过RT-PCR、克隆等方法获取c DNA全长序列,命名为BcucOBP19。结果表明:BcucOBP19基因开放阅读框全长471 bp,编码157个氨基酸,分子量17.5 ku,等电点5.14,具有昆虫OBPs典型的6个保守半胱氨酸位点。BcucOBP19在瓜实蝇各部位均有表达,以15日龄的雌虫触角中表达量最高,在头、腹、翅和前足中表达量较低,且没有显著性差异。     

镉对小麦种子萌发及幼苗生理代谢的影响

为研究Cd对小麦种子萌发和幼苗生理代谢过程的影响,以小麦品种绵阳19为材料,用CdCl2.2.5H2O配制4个浓度梯度,测定小麦萌发种子在不同浓度处理下的芽长、根长、维生素C、游离组氨酸及可溶性糖含量。结果表明,Cd处理对小麦种子萌发有强烈的抑制作用,但不同Cd浓度之间差异不显著（P〉0.05）;低浓度Cd（1mg.L-1）处理对小麦幼苗生长有促进作用,而随Cd浓度增加逐渐转变为抑制效应;幼苗根长对Cd的反应较苗长更敏感,低浓度下即表现为抑制效应;随Cd浓度增加,小麦幼苗的维生素C含量由下降转为上升,分别比对照增加-15.5%、11.2%和26.3%;游离组氨酸含量分别比对照增加28.6%、21.7%和15.5%,而可溶性糖含量则随Cd浓度的增加呈现先降后升再降趋势。说明维生素C、组氨酸和可溶性糖含量均可作为小麦幼苗遭受Cd毒害的早期诊断指标,其中维生素C在小麦幼苗抵御Cd毒害过程中可能起关键作用。