Macrocyclic trichothecene production and sporulation by a biological control strain of Myrothecium verrucaria is regulated by cultural conditions

2009 ◽  
Vol 2 (1) ◽  
pp. 35-43 ◽  
Author(s):  
M. Weaver ◽  
R. Hoagland ◽  
C. Boyette ◽  
R. Zablotowicz
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Worker Safety ◽  
Weed Species ◽  
Continuous Darkness ◽  
Invasive Weed ◽  
Myrothecium Verrucaria ◽  
Macrocyclic Trichothecenes ◽  
The Media ◽  
Macrocyclic Trichothecene

Myrothecium verrucaria is a pathogen of several invasive weed species, including kudzu, and is currently being evaluated for use as a bioherbicide. However, the fungus also produces macrocyclic trichothecene mycotoxins. The safety of this biological control agent during production and handling would be improved if an inoculum could be produced without concomitant accumulation of macrocyclic trichothecenes. Sporulation and trichothecene production by M. verrucaria was evaluated on standard potato dextrose agar (PDA) and a series of complex and defined media. Sporulation on PDA and on agar media with nitrogen as ammonium nitrate or potassium nitrate was more than ten-fold greater then sporulation on the medium with ammonium sulphate as the nitrogen source. Accumulation of macrocyclic trichothecenes was strongly affected by the media composition, with higher levels often associated with higher carbon content in the media. Overall, incubation in continuous darkness resulted in higher macrocyclic trichothecene concentrations. Results support the hypothesis that accumulation of macrocyclic trichothecenes by this fungus can be altered by manipulating carbon and nitrogen sources. Furthermore, the biosynthesis of these mycotoxins may be independent of sporulation, demonstrating that the bioherbicide can be readily produced on solid substrates while simultaneously yielding conidia that are less threatening to worker safety. A more detailed implementation of the concepts demonstrated in this study will facilitate the safe and economical production of this bioherbicide.

scholarly journals Host Range of Herpetogramma basalis (Lepidoptera: Crambidae), a Biological Control Agent for the Invasive Weed Alternanthera philoxeroides (Centrospermae: Amaranthaceae) in China

2019 ◽  
Vol 19 (6) ◽  
Author(s):  
Shihai Chu ◽  
Shengbo Cong ◽  
Ruhai Li ◽  
Youming Hou
Keyword(s):  
Biological Control ◽  
Host Range ◽  
Biological Control Agent ◽  
Oviposition Preference ◽  
Multiple Choice ◽  
Control Agent ◽  
Alternanthera Philoxeroides ◽  
Weed Species ◽  
Amaranthus Tricolor ◽  
Invasive Weed

Abstract Alternanthera philoxeroides (Mart.) Griseb. is an invasive herbaceous amphibious weed species in China. A pyralid moth Herpetogramma basalis (Walker) was discovered feeding on A. philoxeroides through field surveys and may be a potentially useful biocontrol agent. To determine the host range of H. basalis and evaluate its potential to control A. philoxeroides, no-choice and multiple-choice tests were conducted. Herpetogramma basalis fed on target weeds and 29 nontarget plant species. In addition to the target weed A. philoxeroides, H. basalis developed to adult on eight other nontarget species. Herpetogramma basalis survived to adulthood successfully on A. philoxeroides and less successfully on several other Amaranthaceae species. In multiple-choice studies, H. basalis showed a strong oviposition preference for A. philoxeroides over Amaranthus tricolor L. (Centrospermae: Amaranthaceae). Amaranthus tricolor was the only crop plant that supported the complete development of H. basalis. We cautiously recommend H. basalis for the biological control of A. philoxeroides in China.

scholarly journals First Report of Stem Canker of Salsola tragus Caused by Diaporthe eres in Russia

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 110-110 ◽  
Author(s):  
T. Kolomiets ◽  
Z. Mukhina ◽  
T. Matveeva ◽  
D. Bogomaz ◽  
D. K. Berner ◽  
...  
Keyword(s):  
United States ◽  
Biological Control ◽  
Biological Control Agent ◽  
Aqueous Suspension ◽  
Stem Canker ◽  
The United States ◽  
Invasive Weed ◽  
Voucher Specimen ◽  
First Report ◽  
Stem Lesions

Salsola tragus L. (Russian thistle) is a problematic invasive weed in the western United States and a target of biological control efforts. In September of 2007, dying S. tragus plants were found along the Azov Sea at Chushka, Russia. Dying plants had irregular, necrotic, canker-like lesions near the base of the stems and most stems showed girdling and cracking. Stem lesions were dark brown and contained brown pycnidia within and extending along lesion-free sections of the stems and basal portions of leaves. Diseased stems were cut into 3- to 5-mm pieces and disinfested in 70% ethyl alcohol. After drying, stem pieces were placed into petri dishes on the surface of potato glucose agar. Numerous, dark, immersed erumpent pycnidia with a single ostiole were observed in all lesions after 2 to 3 days. Axenic cultures were sent to the Foreign Disease-Weed Science Research Unit, USDA, ARS, Ft. Detrick, MD for testing in quarantine. Conidiophores were simple, cylindrical, and 5 to 25 × 2 μm (mean 12 × 2 μm). Alpha conidia were biguttulate, one-celled, hyaline, nonseptate, ovoid, and 6.3 to 11.5 × 1.3 to 2.9 μm (mean 8.8 × 2.0 μm). Beta conidia were one-celled, filiform, hamate, hyaline, and 11.1 to 24.9 × 0.3 to 2.5 μm (mean 17.7 × 1.2 μm). The isolate was morphologically identified as a species of Phomopsis, the conidial state of Diaporthe (1). The teleomorph was not observed. A comparison with available sequences in GenBank using BLAST found 528 of 529 identities with the internal transcribed spacer (ITS) sequence of an authentic and vouchered Diaporthe eres Nitschke (GenBank DQ491514; BPI 748435; CBS 109767). Morphology is consistent with that of Phomopsis oblonga (Desm.) Traverso, the anamorph of D. eres (2). Healthy stems and leaves of 10 30-day-old plants of S. tragus were spray inoculated with an aqueous suspension of conidia (1.0 × 106 alpha conidia/ml plus 0.1% v/v polysorbate 20) harvested from 14-day-old cultures grown on 20% V8 juice agar. Another 10 control plants were sprayed with water and surfactant without conidia. Plants were placed in an environmental chamber at 100% humidity (rh) for 16 h with no lighting at 25°C. After approximately 24 h, plants were transferred to a greenhouse at 20 to 25°C, 30 to 50% rh, and natural light. Stem lesions developed on three inoculated plants after 14 days and another three plants after 21 days. After 70 days, all inoculated plants were diseased, four were dead, and three had more than 75% diseased tissue. No symptoms occurred on control plants. The Phomopsis state was recovered from all diseased plants. This isolate of D. eres is a potential biological control agent of S. tragus in the United States. A voucher specimen has been deposited with the U.S. National Fungus Collections (BPI 878717). Nucleotide sequences for the ribosomal ITS regions (ITS 1 and 2) were deposited in GenBank (Accession No. EU805539). To our knowledge, this is the first report of stem canker on S. tragus caused by D. eres. References: (1) B. C. Sutton. Page 569 in: The Coelomycetes. CMI, Kew, Surrey, UK, 1980. (2) L. E. Wehmeyer. The Genus Diaporthe Nitschke and its Segregates. University of Michigan Press, Ann Arbor, 1933.

Systematics of Mycosphaerella species associated with the invasive weed Fallopia japonica, including the potential biological control agent M. polygoni-cuspidati

Mycoscience ◽  
2009 ◽  
Vol 50 (3) ◽  
pp. 179-189 ◽  
Author(s):  
Daisuke Kurose ◽  
Naruto Furuya ◽  
Kenichi Tsuchiya ◽  
Harry C. Evans ◽  
Djamila H. Djeddour ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Invasive Weed ◽  
Fallopia Japonica

Factors Affecting Buffalobur (Solanum rostratum) Seed Germination and Seedling Emergence

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 521-525 ◽  
Author(s):  
Shouhui Wei ◽  
Chaoxian Zhang ◽  
Xiangju Li ◽  
Hailan Cui ◽  
Hongjuan Huang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Light Exposure ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Distribution Area ◽  
Burial Depth ◽  
Weed Species ◽  
Continuous Darkness ◽  
Invasive Weed

Buffalobur is a noxious and invasive weed species native to North America. The influence of environmental factors on seed germination and seedling emergence of buffalobur were evaluated in laboratory and greenhouse experiments. The germination of buffalobur seeds occurred at temperatures ranging from 12.5 to 45 C, with optimum germination attained between 25 and 35 C. Buffalobur seeds germinated equally well under both a 14-h photoperiod and continuous darkness; however, prolonged light exposure (≥ 16 h) significantly inhibited the seed germination. Buffalobur seed is rather tolerant to low water potential and high salt stress, as germination was 28 and 52% at osmotic potentials of −1.1 MPa and salinity level of 160 mM, respectively. Medium pH has no significant effect on seed germination; germination was greater than 95% over a broad pH range from 3 to 10. Seedling emergence was higher (85%) for seeds buried at a soil depth of 2 cm than for those placed on the soil surface (32%), but no seedlings emerged when burial depth reached 8 cm. Knowledge of germination biology of buffalobur obtained in this study will be useful in predicting the potential distribution area and developing effective management strategies for this species.

scholarly journals A new trophic interaction between invasive weed, its biological control agent, and local insects: A case study of Chromolaena odorata

2019 ◽  
Vol 20 (4) ◽  
pp. 1006-1011 ◽  
Author(s):  
AKHMAD RIZALI ◽  
MOCHAMMAD SYAMSUL HADI ◽  
PUDJIANTO PUDJIANTO ◽  
DAMAYANTI BUCHORI
Keyword(s):  
Biological Control ◽  
Land Use ◽  
Invasive Species ◽  
Biological Control Agent ◽  
Control Agent ◽  
Trophic Interaction ◽  
Chromolaena Odorata ◽  
Invasive Weed ◽  
Land Use Types

Abstract. Authors. 2019. A new trophic interaction between invasive weed, its biological control agent, and local insects: a case study of Chromolaena odorata. Biodiversitas 20: 1006-1011. Invasive species have been known to cause biotic homogenization. The presence of Chromolaena odorata, an alien invasive weed, in agricultural habitat has outcompeted many crop plants. The presence of alien invasive weed creates a new trophic interaction especially with local herbivores as well as other associate insects. This study was aimed to investigate a new trophic interaction that has been established between C. odorata, its introduced biological control agent, and local insects. The research was conducted in various land-use types in both of Arjuno and Bromo mountain landscape. In each landscape, we surveyed the population density of C. odorata and its biological control agent (a gall fly, Cecidochares connexa) as well as observed the diversity and abundance of other insects associated with C. odorata. Samples were taken along the transect lines at various altitudinal gradients, from 400 to 1100 m asl. In total, 124 species of insects were found associated with C. odorata which include herbivores, parasitoids, and predators. The difference of land-use types affected the population density of C. odorata but not its herbivores (i.e. C. connexa and aphids). A new association was found between the introduced insect, C. connexa and local parasitoids. The field survey also discovered new associations between the invasive weed with local herbivores such as aphids that are found with high abundance. The aphids were found to have a symbiosis interaction with ants such as Anoplolepis gracilipes (invasive species) and Dolichoderus thoracicus. In conclusion, the ecological consequence of the presence of invasive weed species is the shaping of a new trophic interaction with local insects, even with other invasive ant species. This interaction arguably is part of an ecological process that formed an equilibrium interaction which may cause either a negative or positive impact on C. odorata.

Mass Rearing of the Stem-Galling Wasp Tetramesa romana, a Biological Control Agent of the Invasive Weed Arundo donax

2014 ◽  
pp. 163-201 ◽  
Author(s):  
Patrick J. Moran ◽  
John A. Goolsby ◽  
Alexis E. Racelis ◽  
Allen C. Cohen ◽  
Matthew A. Ciomperlik ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Mass Rearing ◽  
Control Agent ◽  
Arundo Donax ◽  
Invasive Weed
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