Key Laboratory of Pests Comprehensive Governance for Tropical crops

Laboratory of, China

Key Laboratory of Pests Comprehensive Governance for Tropical crops

Laboratory of, China
SEARCH FILTERS
Time filter
Source Type

Zhou Y.,Chinese Academy of Sciences | Zhou Y.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Huang J.S.,Chinese Academy of Sciences | Huang J.S.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | And 4 more authors.
Plant Disease | Year: 2017

Banana (Musa spp.) is an important commercial fruit widely cultivated in Hainan Province, which is one of the main banana production areas in China. In 2016, anthracnose symptoms were observed on banana fruits (Musa AAA Cavendish cv. Brazil) harvested from a plantation in Ledong County, Hainan Province. Approximately 17% of banana fruits from the plantation were infected. Anthracnose symptoms began as small light-brown to reddish-brown spots on the surface of banana fruits, and then became sunken lesions as the disease progressed. Colonies with a similar pattern were consistently isolated from the sunken lesions on potato dextrose agar (PDA) medium, and all these colonies were subcultured using the single-spore method. The colonies on PDA plates appeared white at the beginning, and turned dark gray after ∼7 days. Conidia were hyaline, cylindrical, aseptate, smooth, with both ends slightly rounded or with one end round and one end narrowly acute, and measured 10.5 to 16.2 (avg. 13.2) × 3.6 to 4.4 (avg. 3.9) µm (n = 100), L/W ratio = 3.4. Conidial appressoria single, subglobose to slightly ellipsoidal, sometimes irregular, light brown to dark black during the process of development, 5.1 to 8.7 × 3.4 to 6.8 μm, avg. 6.2 × 4.6 μm (n = 65), L/W ratio = 1.3. Occasionally, two new conidia could be induced at both ends of an original conidium that was inoculated in distilled water. Genomic DNA was extracted from a representative isolate HNCS015. The internal transcribed spacer (ITS), β-tubulin (TUB2), and calmodulin (CAL) sequences were amplified using primer pairs of ITS1/ITS4, Bt2a/Bt2b, and CL1/CL2A, respectively. PCR products were sequenced and deposited in GenBank with accession nos. KX673575 (ITS), KX673576 (TUB2), and KX673577 (CAL), respectively. A BLAST search revealed that all three sequences of isolate HNCS015 showed 100% sequence homology with the ITS, TUB2, and CAL sequences of Colletotrichum scovillei (KU680418, KM251964, and KP943586, respectively) in GenBank. Based on morphological characteristics and sequences analysis, the isolate HNCS015 was identified as C. scovillei, which belongs to the C. acutatum species complex (Damm et al. 2012; Kanto et al. 2014). To verify Koch’s postulates, banana fruits (Musa AAA Cavendish cv. Brazil) were surface-disinfested with 70% (v/v) ethanol, followed by washing with sterilized water and wounded using a sterilized needle. A drop of 15 μl conidial suspension (1 × 106 conidia/ml) of isolate HNCS015 was directly placed on each wound, and controls were inoculated with 15 μl sterile distilled water. (Aruna Kumara and De Costa 2015). All banana fruits were incubated in sterilized and transparent plastic boxes at 28°C under a dark/light cycle of 12/12 h. The entire experiment had three replicates, with three banana fruits per replicate. Typical disease symptoms appeared on all fruits that were inoculated with isolate HNCS015 after 4 days, but not on controls. The same pathogen was reisolated from the diseased fruits, but not from controls, fulfilling Koch’s postulates. Banana anthracnose is a common and well-known disease, and can significantly damage fruit’s marketability. The disease is known to be caused by C. gloeosporioides (Intan Sakinah et al. 2013) and C. musae (Aruna Kumara and De Costa 2015), but to our knowledge, C. scovillei has never been reported causing anthracnose disease on banana in the past. This is the first report of C. scovillei causing banana anthracnose in China. © The American Phytopathological Society.


Yang L.Y.,Chinese Academy of Sciences | Yang L.Y.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Chen P.,Hainan University | Guo L.J.,Chinese Academy of Sciences | And 8 more authors.
Plant Disease | Year: 2017

Sacha inchi (Plukenetia volubilis L.) is native to the Amazon rainforest, where it has been cultivated by indigenous people for centuries. Because of its high protein and oil content and general nutritional quality, it is regarded as a promising oil crop. Sacha inchi was introduced to Xishuangbanna by Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, China, in 2006, and about 13.5 ha has been cultivated as under-forest economy crop under Areca catechu trees in Lingshui, Hainan Province, China, since 2014. In June 2016, ∼85% of plants in a field of sacha inchi grown for seeds in Lingshui exhibited symptoms of chlorosis, defoliation, wilting, and/or death. Dissection of roots and vines of symptomatic plants revealed discolored vascular tissue. Symptomatic roots and vines’ pieces (∼5 × 5 mm) from four randomly selected plants were surface-sterilized with 70% ethanol solution treatment for 30 s, washed in sterile water three times, and placed on potato dextrose agar (PDA) medium. Resulting fungal colonies were subcultured using the single-spore method. The colonies on Spezieller Nährstoffarmer agar medium (SNA) plates had creamy white colored growth. Based on observations of 1-week-old isolates, microconidia were fusiform to oval with zero or one septum, dimensions of 7.6 to 17.9 × 2.7 to 5.5 μm (n = 20), and formed at the tips of long unbranched monophialides. Macroconidia were two to four septate, spindle to crescent-shaped, hyaline, and blunt on both ends, 12.2 to 49.4 × 3.2 to 7.5 μm (n = 50). Genomic DNA was extracted from representative isolate YJG3-2. The internal transcribed spacer (ITS), β-tubulin (TUB2), and translation elongation factor 1 (eEF-1α) sequences were amplified using primer pairs of ITS1/ITS4, Bt2a/Bt2b, and EF1-728F/EF1-986R, respectively. PCR products were sequenced and deposited in GenBank with accession numbers KX757042 (ITS), KX757044 (TUB2), and KX757046 (eEF-1α), respectively. A BLAST search revealed that all three sequences of isolate YJG3-2 showed 99% sequence homology with the ITS, TUB2, and eEF-1αsequences of Fusarium solani (KF999012.1, GQ121902.1, and KX454503.1, respectively) represented the best BLAST hit in GenBank. Based on morphological characteristics and sequences analysis, isolate YJG3-2 was identified as F.solani. Pathogenicity of this isolate was confirmed on sacha inchi plants in the greenhouse. Surface disinfected seeds of sacha inchi were immersed in sterilized water overnight and then cultivated in sterile soil in seedling tray until the four leaf stage. Healthy seedlings were selected and transplanted into plastic pots (15 cm diameter, 15 cm height) with sterilized soil after 2 weeks of growth. Ten 45-day-old healthy sacha inchi plants were directly inoculated by irrigating plants with a 50 μl drop of a mixed conidial suspension (106 conidia/ml) of isolate YJG3-2 into each pot near the plants’ roots without wounding after 7 days without watering, and control plants were inoculated with 50 μl of sterile distilled water (Uppala et al. 2013). Symptoms of chlorosis and wilt similar to those in the commercial field were observed over 6 months (September 2016 to April 2017) on 7 of 10 inoculated plants, while control plants were symptomless. Fungal isolates identical to F. solani were reisolated from the symptomatic plants. Sacha inchi is known to be extremely sensitive to Fusarium spp. and Meloidogyne spp. (Mendoza 2008, Senino et al. 2008), but to our knowledge, this is the first report of F. solani causing sacha inchi wilt disease in China. © 2017, American Phytopathological Society. All rights reserved.


Li Q.,Danzhou Agricultural Environmental Science Observation Laboratory | Li Q.,Key laboratory of Pests Comprehensive Governance for Tropical Crops | Zou Y.,Danzhou Agricultural Environmental Science Observation Laboratory | Zou Y.,Key laboratory of Pests Comprehensive Governance for Tropical Crops | And 3 more authors.
Allelopathy Journal | Year: 2013

Precocene II is a major allelochemical produced by the weed Ageratum conyzoides. Its degradation is important in the recovery of A. conyzoides invaded plant communities. Using a strain of N. capsulatum isolated from the A. conyzoides invaded/infested soil; we examined the effects of various factors viz., incubation time, temperature, initial pH, and carbon and nitrogen source on the degradation of precocene II. We found that under optimal conditions with supplementation with a carbon and nitrogen source, up to 79.8% precocene II is degraded by N. capsulatum.


Peng H.,Chinese Academy of Agricultural Sciences | Qi X.,Chinese Academy of Agricultural Sciences | Peng D.,Chinese Academy of Agricultural Sciences | Long H.,Key Laboratory of Pests Comprehensive Governance for Tropical crops | And 4 more authors.
Plant Disease | Year: 2013

Cereal cyst nematodes are the most important plant-parasitic nematodes on cereal crops in wheat producing areas of the world. Heterodera filipjevi was first reported in China in 2010. In this study, species-specific sequence characterized amplified region-polymerase chain reaction (SCAR-PCR) assays for detection and identification of H. filipjevi from infected wheat roots and soil were developed. The species-specific primers were designed according to the randomly amplified polymorphic DNA (RAPD) markers amplified with random primer OPK16. A 646-bp specific fragment of sequence was generated, which characterized amplified regions in H. filipjevi. The detection limitation of the PCR assay was as low as 0.125 μl second-stage juvenile (J2) lysate, 3.9 × 10-3 μl adult female lysate, and 10-3 μl cyst lysate. The method was able to detect the various stages (J2, J3, J4, and female) of H. filipjevi, and a single of nematode in 0.5 g of soil. H. filipjevi was detected by the method in two of six field samples, and one of those samples contained a mixed population of H. filipjevi and H. avenae. This study is the first to provide a definitive diagnostic assay for H. filipjevi in wheat roots and soil. © 2013 The American Phytopathological Society.


Peng H.,Chinese Academy of Agricultural Sciences | Cui J.,Chinese Academy of Agricultural Sciences | Long H.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Long H.,Chinese Academy of Sciences | And 6 more authors.
PLoS ONE | Year: 2016

Pectate lyases are known to play a key role in pectin degradation by catalyzing the random cleavage of internal polymer linkages (endo-pectinases). In this paper, four novel cDNAs, designated Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7, that encode pectate lyases were cloned and characterized from the soybean cyst nematode, Heterodera glycines. The predicted protein sequences of HG-PEL-3, HG-PEL-4 and HG-PEL-6 differed significantly in both their amino acid sequences and their genomic structures from other pectate lyases of H. glycines (HG-PEL-1, HG-PEL-2 and HG-PEL-7). A phylogenetic study revealed that the pectate lyase proteins of H. glycines are clustered into distinct clades and have distinct numbers and positioning of introns, which suggests that the pectate lyase genes of H. glycines may have evolved from at least two ancestral genes. A Southern blot analysis revealed that multiple Hg-pel-6-like genes were present in the H. glycines genome. In situ hybridization showed that four novel pectate lyases (Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hgpel-7) were actively transcribed in the subventral esophageal gland cells. A semi-quantitative RT-PCR assay supported the finding that the expression of these genes was strong in the egg, pre-parasitic second-stage juvenile (J2) and early parasitic J2 stages and that it declined in further developmental stages of the nematode. This expression pattern suggests that these proteins play a role in the migratory phase of the nematode life cycle. Knocking down Hg-pel-6 using in vitro RNA interference resulted in a 46.9% reduction of the number of nematodes that invaded the plants and a 61.5% suppression of the development of H. glycines females within roots compared to the GFP-dsRNA control. Plant hostderived RNAi induced the silencing of the Hg-pel-6gene, which significantly reduced the nematode infection levels at 7 Days post inoculation (dpi). Similarly, this procedure reduced the number of female adults at 40 dpi, which suggests the important roles of this gene in the early stages of parasitism. Our combined data suggest that two types of pectate lyases are present in the H. glycines genome and may have different roles during infection. © 2016 Peng et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Peng H.,Chinese Academy of Agricultural Sciences | Peng D.,Chinese Academy of Agricultural Sciences | Long H.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Long H.,Chinese Academy of Sciences | And 4 more authors.
Nematology | Year: 2014

Plant-parasitic nematodes have developed a series of enzymes to degrade the rigid plant cell wall; β-1,4-endoglucanase is a very important component. Ditylenchus destructor is a migratory endoparasite for which few molecular data have been published. Two novel β-1,4-endoglucanases (Dd-eng-1a and Dd-eng-2) were cloned and characterised from D. destructor. The DD-ENG-1A putative protein consists of a signal peptide, a catalytic domain and a carbohydrate-binding module (CBM). By contrast, the CBM domain is absent from DD-ENG-2. The exon/intron structure and phylogenetic tree indicate that both cellulase genes could have evolved from common ancestral genes. Southern blotting confirmed that the β-1,4-endoglucanases were of nematode origin and a member of a small multi-gene family. In situ hybridisation localised the expression of Dd-eng-1a and Dd-eng-2 to the subventral pharyngeal glands. RT-PCR showed that both genes were expressed in the adult female and second-stage juvenile. The stylet secretions of D. destructor showed clear cellulase activity in carboxymethylcellulose (CMC) plate assay, and similar results were observed in total homogenates and DD-ENG-1A and DD-ENG-2 recombinant proteins. These results demonstrated that D. destructor can produce and secrete functional cellulases. Silencing the putative β-1,4-endoglucanases by double-stranded RNA (dsRNA) resulted in an average decrease in infection of 50%. Successful RNAi in vitro was demonstrated in this study, which confirmed that Dd-eng-1a and Dd-eng-2 play important roles in nematode parasitism. © Koninklijke Brill NV, Leiden, 2014.


Lin Y.-Y.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Jin T.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Jin Q.-A.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Wen H.-B.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops | Peng Z.-Q.,Key Laboratory of Pests Comprehensive Governance for Tropical Crops
Journal of Economic Entomology | Year: 2012

To present the susceptibility of Brontispa longissima (Gestro) (Coleoptera: Hispidae) to insecticides, 22 populations were collected in Southeast Asia from 2007 to 2010. Moreover, the laboratory susceptible strain was maintained. The results demonstrated that the lethal concentration50 value of the susceptible strain to avermectin, -cypermethrin, and acetamiprid was 0.034, 0.024, and 1.843 mg liter -1, respectively. Compared with the susceptible strain, 10 populations developed a medium level of resistance to avermectin (10.8-fold < resistance ratio [RR] < 34.7-fold) and 11 populations had low or minor resistance (3.6-fold


PubMed | Key Laboratory of Pests Comprehensive Governance for Tropical Crops
Type: Journal Article | Journal: Journal of economic entomology | Year: 2012

To present the susceptibility of Brontispa longissima (Gestro) (Coleoptera: Hispidae) to insecticides, 22 populations were collected in Southeast Asia from 2007 to 2010. Moreover, the laboratory susceptible strain was maintained. The results demonstrated that the lethal concentration50 value of the susceptible strain to avermectin, beta-cypermethrin, and acetamiprid was 0.034, 0.024, and 1.843 mg liter(-1), respectively. Compared with the susceptible strain, 10 populations developed a medium level of resistance to avermectin (10.8-fold < resistance ratio [RR] < 34.7-fold) and 11 populations had low or minor resistance (3.6-fold < RR < 9.6-fold), only one population from Qionghai still remained susceptible (RR = 2.04-fold). The Zhangjiang population expressed high resistance (RR = 46.1-fold), five populations expressed medium resistance (10.6-fold < RR < 18.1-fold), and 12 populations had low resistance (5.36-fold < RR < 9.66-fold) for beta-cypermethrin, only four populations maintained low resistance or susceptibility (2.08-fold < RR< 3.49-fold). All populations were susceptible to acetamiprid (1.65-fold < RR < 2.89-fold), except for the Jakarta population that developed minor resistance (4.33-fold). This study shows that the resistance to beta-cypermethrin and avermectin in B. longissima is widespread. However, most populations remain susceptible to acetamiprid. Acetamiprid may be considered an available option for the control of B. longissima and should be considered when designing pest management programs.

Loading Key Laboratory of Pests Comprehensive Governance for Tropical crops collaborators
Loading Key Laboratory of Pests Comprehensive Governance for Tropical crops collaborators