Data on ecology of some Hemiptera species recorded in the forest of Taygetus Mountain,Peloponnesus, Greece

Data on ecology of the Hemiptera species found in the forest area of the Taygetus Mountain during the years 2004–2008 are presented. The scale insects Eulecanium sericeum (Lindinger) (Hemiptera: Coccidae), Nemolecanium graniformis (Wünn) (Hemiptera: Coccidae), Physokermes hemicryphus (Dalman) (Hemiptera: Coccidae), Physokermes inopinatus Danzig & Kozár (Hemiptera: Coccidae), Dynaspidiotus abietis (Schrank) (Hemiptera: Diaspididae) and the aphid Cinara confinis (Koch) (Hemiptera: Aphididae) were found infesting fir trees Abies cephalonica (Pinaceae) and the scale species Lineaspis striata (Newstead) (Hemiptera: Diaspididae) and Planococcus vovae (Nasonov) (Hemiptera: Pseudococcidae) were found on Juniperus oxycedrus (Cupressaceae). The coccids P. hemicryphus, P. inopinatus, N. graniformis and the diaspidid D. abietis complete one generation per year in the study area. The predatory species Chilocorus bipustulatus (L.), Exochomus quadripustulatus (L.), Ceratomegilla undecimnotata (Schneider), Coccinella septempunctata L. and Scymnus sp. (Coleoptera: Coccinellidae) were observed on the infested plants. The encyrtid Pseudorhopus testaceus (Ratzeburg) parasitized female adults of P. hemicryphus. The parasitization level reached 47.8% in July.     

Comparative population structure and trichothecene mycotoxin profiling of Fusarium graminearum from corn and wheat in Ontario,central Canada

Fusarium graminearum causes fusarium head blight (FHB) of wheat and gibberella ear rot (GER) of corn in Canada and also contaminates grains with trichothecene mycotoxins. Very little is known about trichothecene diversity and population structure of the fungus from corn in Ontario, central Canada. Trichothecene genotypes of F. graminearum isolated from corn (n = 452) and wheat (n = 110) from 2010 to 2012 were identified. All the isolates were deoxynivalenol (DON) type. About 96% of corn isolates and 98% of wheat isolates were 15‐acetyl deoxynivalenol (15ADON) type. The fungal population structures from corn (n = 313) and wheat (n = 73) were compared using 10 variable number tandem repeat (VNTR) markers. The fungal populations and subpopulations categorized based on host, cultivar groups, years and geography showed high gene (H = 0.818–0.928) and genotypic (GD = 0.999–1.00) diversity. Gene flow was also high between corn and wheat population pairs (Nm = 8.212), and subpopulation pairs within corn (Nm = 7.13–23.614) or wheat (Nm = 19.483) populations. Phylogenetic analysis revealed that isolates from both hosts were F. graminearum clade 7. These findings provide baseline data on 3‐acetyl deoxynivalenol (3ADON) and 15ADON profiles of F. graminearum isolates from corn in Canada and are useful in evaluating mycotoxin contamination risks in corn and wheat grains. Understanding the fungal genetic structure will assist evaluation and development of resistant cultivars/germplasm for FHB on wheat and GER on corn.     

嘧啶联吡唑甲酰胺类化合物的合成及除草活性

设计合成了一系列结构新颖的嘧啶联吡唑甲酰胺类化合物5a~5o,其结构均经过1H NM R和MS分析确证。初步生物活性测试结果表明:在有效成分150 g/hm2剂量下苗后茎叶喷雾处理时,化合物(R)-N-[1-(4-氯苯基)乙基]-3-二氟甲基-1-(4,6-二甲氧基嘧啶-2-基)-1H-吡唑-4-甲酰胺(5c)、N-[1-(4-氯苯基)乙基]-1-(4,6-二甲氧基嘧啶-2-基)-N-甲基-3-三氟甲基-1H-吡唑-4-甲酰胺(5i)和N-[1-(4-氯苯基)乙基]-1-(4,6-二甲氧基嘧啶-2-基)-3-三氟甲基-1H-吡唑-4-甲酰胺(5k)对繁缕Stellaria media的抑制率高达90%以上;而同样剂量下苗前土壤喷雾处理时,化合物N-[1-(4-氯苯基)乙基]-3-二氟甲基-1-(4,6-二甲氧基嘧啶-2-基)-1H-吡唑-4-甲酰胺(5b)和5c对繁缕的抑制率达100%。该类结构化合物有望作为除草先导化合物进行开发。     

Interaction between optical isomerism and plant pharmacological action,change of modes of action and chirality of 1-(α-methylbenzyl)-3-p-tolylurea

The optical isomers, (R)-1(α-methylbenzyl)-3-p-tolylurea ((R)-MBU) and (S)-1-(α-methylbenzyl)-3-p-tolylurea ((S)MBU), which are analogues of daimuron [1-(α,α-dimethylbenzyl)-3-p-tolylurea], a herbicide for Cyperaceae weeds and a safener for paddy rice, exhibited different biological responses. These two physiological properties of daimuron were observed separately in (R)-MBU and (S)-MBU. Only (R)-MBU had herbicidal activity against Cyperaceae weeds, while the (S)-isomer was a more effective safener against bensulfuron-methyl (BSM) injury of rice seedlings than was (R)-MBU. (S)-MBU promoted root growth of rice seedlings, but the (R)-enantiomer inhibited root growth. (S)-MBU was a more potent inhibitor than (R)-MBU on PS II reaction of spinach broken chloroplasts. Furthermore, (S)-MBU and (R)-MBU showed cross intergenus selective phytotoxicity among the Gramineae plants, Oryza sativa L. (rice, cv. Tsukinohikari, japonica), Triticum aestivum L. (wheat, cv. Norin No. 61) and Echinochloa crusgalli var. frumentacea Wight, on root growth inhibition in the dark.     

Five-year survey uncovers extensive diversity and temporal fluctuations among fusarium head blight pathogens of wheat and barley in Brazil

We conducted a five-year survey (2011–2015) of barley and wheat fields in Paraná state, Brazil, obtaining 754 Fusarium isolates from spikes with fusarium head blight (FHB)-symptoms. Multilocus genotyping and TEF-1α gene sequence analyses confirmed the dominance of the F. graminearum species complex (FGSC, 75.7%), but F. poae (11.5%), as well as F. avenaceum and related members of the F. tricinctum species complex (FTSC, 8.1%) appeared as substantial contributors to FHB. Within the FGSC, F. graminearum of the 15-ADON genotype was dominant (63%), followed by F. meridionale of the NIV genotype (23.1%), F. cortaderiae of the NIV (7%) or 3-ADON (2.6%) genotypes, and F. austroamericanum (3.8%) of the 3-ADON genotype. Substantial variation in pathogen composition was observed across years, with F. poae and F. meridionale frequencies significantly elevated in some years. Most F. poae strains produced DAS, diANIV, and butenolide, but not neosolaniol, T-2, or HT-2. All FTSC species produced moniliformin. Enniatin production was widespread among FTSC species, with the single F. acuminatum strain found to be the strongest producer of enniatins. Our findings confirm FGSC as a major contributor to FHB and expand considerably our knowledge of the presence, frequency, and conditions under which other pathogens may emerge, altering the spectrum of toxins that may accumulate in grain.     

迷宫漏斗蛛对假眼小绿叶蝉的捕食功能反应

室内试验表明 ,迷宫漏斗蛛雌、雄蛛对假眼小绿叶蝉的捕食功能反应均为HollingⅡ型反应 ,迷宫漏斗蛛对假眼小绿叶蝉的控制能力雌蛛大于雄蛛。捕食量上限雌蛛为295.3头,雄蛛为120.7头 ,说明这种蜘蛛对假眼小绿叶蝉有很大控制潜力     

Synthesis,spectral properties and insecticidal,acaricidal and ovicidal activities of some O-(1,5-disubstituted- 6-oxo-12H-pyridazin-4-yl) phosphorothioates

A synthesis of O,O-dialkyl, O-alkyl O-2-chloroethyl (or O-2-ethoxyethyl) O-(1,5-disubstituted-6-oxo-1H-pyridazin-4-yl) phosphorothioates is described. Infrared, Raman and ultraviolet spectra of the compounds prepared are interpreted. The wave-numbers of the v(C? C) bands were correlated with substituent constants. Good linear correlations of v(C? O) with σ, σ^F, σ_I and σ_R were observed for compounds containing various substituents in the neighbourhood of the keto group of the pyridazinone ring. The insecticidal, acaricidal and ovicidal activities of O-(ethyl or isopropyl), O-(alkyl, 2-chloroethyl, or 2-ethoxyethyl) O-(5-methoxy-1-methyl-6-oxo-1H- pyridazin-4-yl) phosphorothioates, O-ethyl O-isopropyl O-(5-methoxy-1-substituted-6-oxo-1H-pyridazin-4-yl) phosphorothioates and O-ethyl O-isopropyl O-(1-methyl-5-substitutedd-oxo-1H-pyridazin-4-yl) phosphorothioates are reported together with the toxicity of some of these compounds to rats.     

Susceptibility of the obscure mealybug,Pseudococcus viburni (Signoret) (Pseudococcidae), to South African isolates of entomopathogenic nematodes

Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae), the obscure mealybug, is a serious pest of apples and pears in South Africa. The potential use of entomopathogenic nematodes (EPNs) against P. viburni was assessed in laboratory bioassays. The results showed Heterorhabditis zealandica (J34) to be most effective, causing 80% mortality of P. viburni 48-h post inoculation at 25 ºC. After 48 h, the LD₅₀ and LD₉₀ values were 54 and 336 nematodes, respectively. H. zealandica (J34) and Steinernema yirgalemense successfully reproduced in P. viburni, with H. zealandica (J34) attaining greater penetration ability than did the S. yirgalemense. Mealybug size affected infectivity, with the crawlers being less susceptible (22%) than were the adults and intermediates, with mortalities of 78% and 76%, respectively. H. zealandica (J34) were able to enter the apple core of infested apples, where they infected the P. viburni. This work represents the first report on using EPNs to control P. viburni.     

Evidence for Resistance to Bacillus thuringiensis (Bt) subsp. kurstaki HD-1, Bt subsp. aizawai and Abamectin in Field Populations of Plutella xylostella from Malaysia

The efficacy of Bacillus thuringiensis (Bt) subsp. kurstaki HD-1 (‘Dipel’™; Btk; CryIA & CryII) and Bt. subsp. aizawai (‘Florbac’™; Bta; CryIA & CryIC) was assessed against larvae from various field populations of Plutella xylostella (F2 generation) collected in the Cameron Highlands, Malaysia in April 1994 and a lowland population (SERD 2; F10 generation) collected in December 1993. Evidence of resistance to Btk and to a lesser extent Bta is reported in these populations (LC₅₀ Toxicity Ratios [TR]=3–14 and 2–8 respectively), most notably in SERD 2. The first recorded evidence of resistance to abamectin (TR=17–195-fold) in field populations of P. xylostella is also reported. In an unselected sub-population of SERD 2, the TR values for Btk, Bta and abamectin declined 2- to 3-fold (P<0·01) over six generations in the laboratory (F10–F16) while in sub-populations of SERD 2 selected with these products (F11–F15) there was a significant (P<0·01) increase in the TR (15-, 3- and 2·5-fold respectively) when compared with the F10 generation. This suggests the presence of marked resistance to Btk and some resistance to Bta and abamectin. There is also evidence of slight cross-resistance to Btk in the Bta-selected sub-population but no evidence for the reverse selection of resistance or for cross-resistance between Btk and abamectin. Concurrent selection studies (F11–F15) with another sub-population of SERD 2 demonstrated resistance to the acylurea insect growth regulator, teflubenzuron (‘Nomolt’™) (29-fold increase in TR). Based on the selection experiments with SERD 2, estimates of realised heritability (h²) of resistance gave very high values for teflubenzuron and Btk (c.0·7) and moderate values for abamectin and Bta (c.0·3). The results are discussed in relation to integrated pest management (IPM) and insecticide resistance management (IRM) strategies for P. xylostella.     

Control of dodder (Cuscuta chinensis Damk) in niger (Guizotia abyssinica L.f. Cass) with chlorpropham

Chlorpropham at 4 kg/ha applied on the day following the initiation of dodder (Cuscuta chinensis Damk) germination, controlled the dodder without damaging the associated crop of niger (Guizotia abyssinica L.f. Cass) Lutte contre la cuscute (Cuscuta chinensis Damk) dans les cultures de Guizotia abyssinica (L.f. Cass) avec le chlor-prophame. Le chlorprophame è kg/ha appliqué le jour suivant le début de la germination de la cuscute (Cuscuta chinensis Damk) a maîtrisé celle-ci tout en respectant la culture associée de Guizotia abyssinica (L.f. Cass). Bekämpfung von Cuscuta chinensis (Damk) in Guizotia abyssinica (L.f. Cass) mit Chlorpropham Cuscuta chinensis (Damk) wurde ohne Schädigung der Kultur (Guizotia abyssinica L.f. Cass) bekämpft, wenn 4 kg/ha Chlorpropham einen Tag nach Keimbeginn der Seide appliziert wurde.     

Timing and extent of hypersensitive response are critical to restrict local and systemic spread of Pepper mild mottle virus in pepper containing the L 3 gene

Amino acid changes in Pepper mild mottle virus (PMMoV) coat protein (CP) that enhance, decrease, or nullify the resistance-inducing activity in Capsicum plants carrying the L ³ gene have been identified. In this study, molecular events underlying the L ³ -gene-mediated resistance were analyzed through the expression of hypersensitive response (HR)-related genes, HSR203J-Cc and HIN1-Cc, and defense-related genes, PR1-Cc and PR4b-Cc, upon infection with PMMoV CP mutants. The expression kinetics of the genes correlated with the degree of restriction of virus distribution in the inoculated leaves. The results suggest that the timing and extent of HR are critical factors to restrict virus spread both locally and systemically in L ³ -gene-mediated resistance.The nucleotide sequence data reported are available in the DDBJ/GenBank/EMBL databases under accession numbers AB162220 (HSR203J-Cc), AB162221 (HIN1-Cc), AB162222 (PR1-Cc), and AB162223 (PR4b-Cc)     

Life tables of Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) (Lepidoptera: Noctuidae) on different cultivated plants

Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) is a cosmopolitan species that feeds on numerous cultivated plants and herbaceaus plants. Agrotis ipsilon causes significant economic losses in various agricultural products, especially in indisturial plants and vegetables in Turkey and worldwide. In this study, the effects on the biology and reproductive potential of lettuce (Lactuca sativa L., Asteraceae), maize (Zea mays L., Poaceae), sugarbeet (Beta vulgaris var. saccharifera Alef.,Amaranthaceae) and potato (Solanum tuberosum L., Solanaceae) which are essential host plants of A. ipsilon were investigated under climatized conditions of 28?±?1 °C, 60%?±?10 r.h., and 16 h daily artificial light. The data obtained were analyzed by using an age-stage two-sex life table. Agrotis ipsilon had five larval stages fed on lettuce, whereas seven larval stages were fed on other host plants. Agrotis ipsilon showed the best development and reproduction on lettuce, followed by sugar beet. When A. ipsilon is reared on lettuce the intrinsic rate of increase (r?=?0.1237 d^?1), finite rate of increase (λ?=?1.1317 d^?1) and net reproductive rate (R₀?=?403.06 offspring/individual) were found higher and the mean generation times (T?=?48.51 d) is shorter than those in other host plants. According to these results, A. ipsilon can cause the most damage to lettuce among studied plants.

     

Phytotoxic and antiphytopathogenic compounds from Thai Alpinia galanga (L.) Willd. rhizomes

The management of weeds and diseases that are caused by phytopathogenic fungi is important for preventing the loss of agricultural products. The aim of the present study was to identify phytotoxic and antiphytopathogenic agents from the Thai Alpinia galanga rhizome. Extracts of the dried rhizomes of A. galanga (Zingiberaceae) were separated and tested for phytotoxic activity against lettuce (Lactuca sativa L. cv. Great Lakes) and Italian ryegrass (Lolium multiflorum Lam. cv. Wasefudou) and for antiphytopathogenic activity against Alternaria porri, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora nicotianae. 1′‐Acetoxychavicol acetate ( 1 ) was identified as one of the main components, together with trans‐p‐coumaryl acetate ( 3 ) and trans‐p‐acetoxycinnamyl acetate ( 2 ). 1′‐Acetoxychavicol acetate ( 1 ) was solvolyzed with 2% EtOH to yield trans‐p‐coumaryl ethyl ether ( 6 ), trans‐p‐coumaryl acetate ( 3 ) and trans‐p‐coumaryl alcohol ( 5 ). 1′‐Acetoxychavicol acetate ( 1 ) completely inhibited the root growth of the lettuce seedlings at 50 μg mL^–1, but had a weaker inhibitory effect on the growth of Italian ryegrass. 1′‐Acetoxychavicol acetate also inhibited the growth of P. nicotianae and A. porri, with minimum inhibition concentration values of 15.6 and 31.5 μg mL^–1, respectively. The plant growth‐inhibitory activity and fungal growth‐inhibitory activity of trans‐p‐coumaryl acetate ( 3 ), trans‐p‐coumaryl ethyl ether, trans‐p‐coumaryl alcohol ( 5 ) and trans‐p‐acetoxycinnamyl acetate ( 2 ) were lower than those of 1′‐acetoxychavicol acetate. A structure–activity relationship suggested that the strong phytotoxic and antiphytopathogenic activity of 1′‐acetoxychavicol acetate relied on the 1′‐acetoxyl group.     

Tagging and mapping a second resistance gene for <Emphasis Type="Italic">Fusarium</Emphasis> wilt race 0 in chickpea

A second gene conferring resistance to the chickpea wilt pathogen, Fusarium oxysporum f. sp ciceris race 0, has been mapped to linkage group 2 (LG2) of the chickpea genetic map. Resistance to race 0 is controlled by two genes which segregate independently; one present in accession JG62 (Foc0 ₁ /foc0 ₁ ) and mapping to LG5 and the second present in accession CA2139 (Foc0 ₂ /foc0 ₂ ) but remaining unmapped. Both genes separately confer complete resistance to race 0 of the wilt pathogen. Using a Recombinant Inbred Line (RIL) population that segregated for both genes (CA2139 × JG62) and the genotypic information provided by two markers flanking Foc0 ₁ /foc0 ₁ ten resistant lines containing the resistant allele Foc0 ₂ /foc0 ₂ were selected. Genotypic analysis using these ten resistant lines paired with ten susceptible RILs, selected in the same population, revealed that sequence tagged microsatellite sites (STMS) markers sited on LG2 were strongly associated with Foc0 ₂ /foc0 ₂ . Linkage analysis, using data from two mapping populations (CA2139/JG62 and CA2156/JG62), located Foc0 ₂ /foc0 ₂ in a region where genes for resistance to wilt races 1, 2, 3, 4 and 5 have previously been reported and which is highly saturated with tightly-linked STMS markers that could be used in marker-assisted selection (MAS).     

Effect of the endophyte <Emphasis Type="Italic">Neotyphodium lolii</Emphasis> on susceptibility and host physiological response of perennial ryegrass to fungal pathogens

The effect of the endophyte Neotyphodium lolii on susceptibility of perennial ryegrass (Lolium perenne) to ten fungal pathogens in detached leaves was studied. The pathogens were Alternaria alternata, Ascochyta leptospora, Bipolaris sorokiniana, Curvularia lunata, Fusarium acuminatum, F. avenaceum, F. chlamydosporum, F. solani, F. oxysporum, and Gliocladium roseum. In addition, the effect of the endophyte on four pathogens (A. alternata, B. sorokiniana, Curvularia lunata and F. avenaceum) in living plants was studied, and changes in host superoxide dismutase (SOD) or peroxidases (POD) activity were examined. The total lengths of lesions on detached leaves were greater (P < 0.05) on E- plants than on E+ plants except for A. leptospora although differences between E+ and E- were not consistently significant at all sample times (days after inoculation).The numbers of lesions were greater (P < 0.05) and the lesions were larger (P < 0.05) on intact E- plants than on intact E+ plants for all of the four pathogens. SOD enzyme activity was significantly greater (P < 0.05) in E+ plants than in E- plants only for A. alternata, C. lunata, and F. avenaceum. POD enzyme activity was significantly greater (P < 0.05) in E+ plants than in E- plants only for C. lunata, B. sorokiniana and the uninoculated control.     

Multiple virus infections of lablab [<Emphasis Type="Italic">Lablab purpureus</Emphasis> (L.) Sweet] in Nigeria

Leaf samples of Lablab purpureus collected from two agroecological zones of Nigeria—the northern guinea savanna zone (NGSZ) and the derived savanna zone (DSZ)—were infected with viruses when serologically indexed against available antisera. Approximately 31.1 and 81.1% of the leaf samples collected from the NGSZ and DSZ, respectively, were infected. Seven viruses were found: Bean common mosaic virus (BCMV), Cowpea aphid-borne mosaic virus (CABMV), Cucumber mosaic virus (CMV), Cowpea mottle virus (CPMoV), Cowpea severe mosaic virus (CPSMV), Southern bean mosaic virus (SBMV) and Tobacco mosaic virus (TMV) were detected from samples collected from NGSZ, while CMV, CPMoV, Cowpea mosaic virus (CPMV) and CPSMV were detected from samples from DSZ.     

Genetic analysis and PCR-based identification of major <Emphasis Type="Italic">Fusarium</Emphasis> species causing head blight on wheat in Japan

Identifying the Fusarium species cause Fusarium head blight (FHB) and produces mycotoxins in wheat and other cereal is difficult and time consuming because of confusing phenotypic classification systems. In Japan, the F. graminearum complex, F. culmorum, F. avenaceum, and Microdochium nivale predominantly cause FHB. The internal transcribed spacer (ITS) and 5.8S of rDNA, a partial sequence of β-tubulin and mitochondrial cytochrome b (cytb) genes of the four species were PCR-amplified and analyzed. On the basis of the ITS, β-tubulin and cytb sequences, F. avenaceum and M. nivale are distinct from the F. graminearum complex and F. culmorum, whereas the F. graminearum complex is closely related to F. culmorum. Moreover, thiophanate–methyl-resistant isolates of the F. graminearum complex and F. culmorum did not have an amino acid substitution at amino acid codon 198 or 200 of β-tubulin. In contrast, very highly or highly thiophanate–methyl-resistant isolates of M. nivale had Glu (GAG) substituted with Ala (GCG) or Lys (AAG) at codon 198, respectively. The allele-specific PCR assay was used to identify the F. graminearum complex and F. culmorum, and these Fusarium species could be distinguished rapidly.     

Pathogenic variation of Mycosphaerella species infecting banana and plantain in Nigeria

Mycosphaerella species that cause the ‘Sigatoka disease complex’ account for significant yield losses in banana and plantain worldwide. Disease surveys were conducted in the humid forest (HF) and derived savanna (DS) agroecological zones from 2004 to 2006 to determine the distribution of the disease and variation among Mycosphaerella species in Nigeria. Disease prevalence and severity were higher in the HF than in the DS zone, but significant (P < 0·001) differences between agroecological zones were only observed for disease severity. A total of 85 isolates of M. fijiensis and 11 isolates of M. eumusae were collected during the survey and used to characterize the pathogenic structure of Mycosphaerella spp. using a putative host differential cultivar set consisting of Calcutta‐4 (resistant), Valery (intermediate) and Agbagba (highly susceptible). Area under disease progress curve (AUDPC) was higher on all cultivars when inoculated with M. eumusae than with M. fijiensis, but significant (P < 0·05) differences between the two species were only observed on Valery. Based on the rank‐sum method, 8·3% of the isolates were classified as highly aggressive and 46·9% were classified as aggressive. About 11·5% of all the isolates were classified as least aggressive, and all of these were M. fijiensis. The majority of M. eumusae isolates (seven out of 11; 64%) were classified as aggressive. A total of nine pathotype clusters were identified using cluster analysis of AUDPC. At least one M. fijiensis isolate was present in all the nine pathotype clusters, while isolates of M. eumusae were present in six of the nine clusters. Isolates in pathotype clusters III and V were the most aggressive, while those in cluster VIII were the least aggressive. Shannon’s index (H) revealed a more diverse Mycosphaerella collection in the DS zone (H = 1·81) than in the HF (H = 1·50) zone, with M. fijiensis being more diverse than M. eumusae. These results describe the current pathotype structure of Mycosphaerella in Nigeria and provide a useful resource that will facilitate screening of newly developed Musa genotypes for resistance against two important leaf spot diseases of banana and plantain.     

河南省玉米茎基部镰刀菌的形态和分子鉴定

 为明确河南省玉米茎基部镰刀菌(Fusarium spp.)的种群组成及分布, 2011和2012年, 我们采集了河南省14个地市42个县(区)的玉米茎基腐病病样, 分离得到163个镰刀菌单孢菌株。首先对菌株进行了形态学鉴定, 在此基础上使用镰刀菌种特异性引物进行了PCR检测;对于部分PCR检测未能确认的菌株进行了Translation elongation factor 1-α(TEF-1α)基因片段测序及BLAST分析, 最终将163个菌株鉴定到种。结果表明在163个菌株中, 禾谷镰刀菌F. graminearum为优势种, 占44.2%(72株), 其次为层出镰刀菌F. proliferatum和轮枝镰刀菌F. verticillioides, 分别占28.8%(47株)和27.0%(44株)。豫西北的焦作(47.6%)、洛阳(50.0%)及豫中的许昌(45.5%)均以F. verticillioides为主, 豫东的商丘(42.9%)、开封(57.1%)以F. proliferatum为主, 豫北的安阳(66.7%)、濮阳(71.4%)、新乡(62.5%)和豫南的南阳(57.1%)、驻马店(45.0%)以及中部的郑州(57.1%)、漯河(66.7%)则均以F. graminearum为优势种。     

2011-2012年度中国六省小麦叶锈菌群体毒性分析

 为明确2011-2012年度云南、四川、青海、陕西、甘肃和河南小麦叶锈菌的毒性特点,用31个近等基因系或已知抗病基因品种为鉴别寄主,对从六省采集的180份小麦叶锈菌标样进行了苗期毒性分析,共鉴定出62个致病类型,主要包括SHJ(10%)、THT(8.9%)、PHK(6.1%)、SHN(5%)、PHT(4.4%)、SHD(4.4%)、PCH(3.9%)、THP(3.3%)和THK(3.3%)。其中对Lr2c、Lr10、Lr14a、Lr14b、Lr33和Lr36的毒性频率均超过75%,说明这些抗病基因的利用价值已经不大;对Lr9、Lr19、Lr24、Lr25、Lr28、Lr29、Lr38和Lr42的毒性频率低于30%,说明其在生产中仍然有效;对Lr2a、Lr3、Lr3bg、Lr20、Lr30和Lr32的毒性频率在六省中差异较大。毒性多态性结果表明云南和四川的小麦叶锈菌群体毒性多态性较高,其次为河南、甘肃和陕西,青海的毒性多态性最低。