**7. References**

108 Soybean – Genetics and Novel Techniques for Yield Enhancement

fungi, little homogeneity was confirmed between the isolates comprising clusters B and D

It was shown that *C. kikuchii* isolates from the same geographic region appeared in different groups. Molecular analyses showed intraspecific variability within *C. kikuchii* isolates from soybean collected in different regions, so it was difficult to establish a relationship between this variability and that of the soybean cultivars from which *C. kikuchii* isolates were obtained. Similar results had been previously reported by González et al. (2008) and Almeida et al. (2005). According to the results here obtained, Argentinian populations of *C. kikuchii* are phenotypically, genotypically and geographically variable. In agreement with Almeida et al. (2005), who consider that this pathogen is easily transmitted by seeds, it is not

In Argentina, and in this region in particular, there has been a rapid increase in the soybean producing area since 1970 (Aizen et al., 2009); therefore, the traffic of seeds from traditional to new areas could be responsible for the geographical variability since *C. kikuchii* is a seed borne pathogen. Unfortunately, an insufficient number of isolates was obtained from each area to permit the evaluation of gene flow among populations more

For countries like Argentina, with large soybean areas it is very important to know the variability of the pathogen in advance in order to prevent resistant cultivars when sown in

Few studies have been reported concerning the molecular characterization of genus *Cercospora*. Therefore, widening the scope of knowledge about this pathogen biology, and developing strategies to control the cultures intended for human and/or animal use in this

Results revealed a considerable degree of phenotypic and genotypic variation in the population of *C*. *kikuchii* infecting soybean crops from the centre-northern region of Santa Fe

From the phenotypic- in vitro- viewpoint, isolates were differentiated by color and size of the colonies, as well as by sporulation capacity. As far as genotypic aspect is concerned, differences in the genome of fungi from the different regions were detected, aside from

The two statistical techniques applied proved to be adequate since not only genetic variants could be detected among the isolates under study but also similar clusters were obtained in both of them, thereby giving validity to the results. The detection of genetically similar isolates, on the other hand, would make decision-making easier so as to intervene in health issues such as the prevention of diseases produced by these phytopathogenic

This work was carried out within CAI+D 2009 Program (Universidad Nacional del Litoral,

Argentina). The authors are grateful to engineers participating in RiiA Program.

generated by AGNES and clusters 2 and 5 obtained with FANNY.

surprising to find the same haplotypes in different regions.

region, therefore, would be a great contribution of this work.

differences among isolates from the same population.

accurately.

different areas.

**5. Conclusions** 

Province, Argentina.

**6. Acknowledgements** 

fungi.


http://etd.lsu.edu/docs/available/etd-12112003-143624/


Phenotypic and Genotypic Variability in

8448136109, España

ISSN 1415-4757

15, ISSN 0798-0035

189, No.1, pp 97-101, ISSN 0378-1097

Vol.168, No.1, pp. 11-22, ISSN 0301-486X

In: *El Litoral*, (07.04.2007), Available from

Vol.12, pp. 1-84, ISSN 0073-4748

http://www.minagri.gob.ar/new/0-

*Cercospora kikuchii* Isolates from Santa Fe Province, Argentina 111

Penna, J. & Lema, D. (2002). Adoption of herbicide resistant soybeans in Argentina: an

Peña, D. (2002). *Análisis de datos multivariantes*, McGraw-Hill S.A./Interamericana, ISBN

Pujol Vieira dos Santos, A., Santos Matsumura, A. & Van der Sand, S. (2002). Intraspecific

Redondo, C., Cubero, J. & Melgarejo P. (2009). Characterization of *Penicillium* species by

Secretaría de Agricultura, Ganadería, Pesca & Alimentos (SAGPyA). (December 2003).

Salvador, D. & Garrido, M. (1990). Características culturales y patogenicidad del hongo

Sambrook, J., Fritsch, E. & Maniatis, T. (1989). *Molecular Cloning: a Laboratory Manual* (2nd

Sillón, M. (April 2007). Proyecto de asintomáticas: ¿Qué esconden nuestros cultivos de soja?,

 http://www.ellitoral.com/ index.php/diarios/2007/04/07/laregion/REG-11.html Solheim, W. (1929). Morphological studies of genus *Cercospora*. *Illinois Biological Monographs*.

Stenglein, S. & Ballatti, P. (2006). Genetic diversity of *Phaeoisariopsis griseola* in Argentina as

Tigano, M., Aljanabi, S. & Marques de Mello, S. (2003). Genetic variability of Brazilian

Torgo, L. (2003). *Data Mining with R: learning with case studies*. CRC Press, ISBN

Upchurch, R., Walker, J., Rollins, J., Ehrenshaft, M. & Daub, M. (1991). Mutants of *Cercospora* 

Williams, J., Kubelik, A., Livak, K., Rafalski, J. & Tingey, S. (1990). DNA polymorphisms

revealed by pathogenic and molecular markers. *Physiological and Molecular Plant* 

*Alternaria* spp. isolates as revealed by RAPD analysis. *Brazilian Journal of* 

9781439810187. 05.05.2010, Available from http://www.math.iupui.edu

*kikuchii* altered in cercosporin synthesis and pathogenicity. *Applied of Environmental* 

amplified by arbitrary primers are useful as genetic markers. *Nucleic Acids Research*,

0/programas/dma/Informe\_diario/2003/infogra\_2003-12-05.pdf

edition), Cold Spring Harbor, ISBN 0-87969-309-6, New York

*Pathology*, Vol.68, No.4-6, pp. 158-167, ISSN 0885-5765

*Microbiology*, Vol.34, No.2, pp. 117-119, ISSN 1517-8382

/~samiran/STAT521f09\_files/DataMiningWithR.pdf

Vol.18, No.22, pp. 6531-6535, ISSN 0305-1048

*Microbiology*, Vol.57, No.10, pp. 2940-2945, ISSN 0099-2240

http://www.inta.gov.ar/ies/docs/doctrab/adoption\_dt\_18.PDF

internal transcribed spacers of the ribosomal region. *FEMS Microbiology Letters*, Vol.

economic analysis, In: *Economic and Environmental impacts of Agbiotech*, Kalaitzandonakes N, Dordrecht: Kluwer Academic Publishers, Available from

genetic diversity of *Drechslera triciti-repentis* as detected by a ramdom amplified polymorphic DNA analysis. *Genetic and Molecular Biology*, Vol.25, No.2, pp. 243-250,

ribosomal DNA sequencing and BOX, ERIC and REP-PCR analysis. *Mycopathologia*,

Mercado de granos, In: *Informe diario*, (05.12.2003), Available from

causante de la mancha en cadena del sorgo. *Fitopatologia Venezolana*, Vol.3, pp. 11-


Ellis, M. (1971). *Dematiaceous Hyphomycetes.* Commonwealth Mycological Institute, ISBN

Everitt, B. & Hothorn, T. (2009). *A handbook of statistical analyses using R* (2nd Edition),

Fajola, A. (1978). Cercosporin, a phytotoxin from *Cercospora* species. *Physiological Plant* 

Fernández, F., Glawe, D. & Sinclair, J. (1991). Microcycle conidiation and nuclear behavior

Formento, N. (December 2005). Enfermedades de fin de ciclo de la soja en Entre Ríos, In: *Instituto Nacional de Tecnología Agropecuaria*, 10.11.2010, Available from http://www.inta.gov.ar/parana/info/documentos/produccion\_vegetal/soja/enf

Gams, W., Verkleij, G. & Crous, P. (2007). *CBS Course of Mycology* (5th edition),

González, A., Turino, L., Latorre Rapela, M. & Lurá, M. (2008). *Cercospora kikuchii* aislada en

Ivancovich, A. & Botta, G. (October 2003). Enfermedades de final de ciclo de la soja, In: *Instituto Nacional de Tecnología Agropecuaria*, 08.10.10, Available from http://www.inta.gov.ar/rafaela/info/documentos/misc100/misc100\_15.pdf Jenns, A., Daub, M. & Upchurch, R. (1989). Regulation of cercosporin accumulation in

Johnson, R. & Wichern, D. (1998). *Applied multivariate statistical analysis* (4th edition), Prentice

Kaufman, L. & Rousseeuw, P. (1990). *Finding groups in data. An introduction to cluster analysis*

Kempken, F. & Kück, U. (1998). Transposons in filamentous fungi: facts and perspectives.

Kuyama, S. & Tamura, T. (1957). Cercosporin. A pigment of *Cercospora kikuchii* Matsumoto et

Lurá, M., Di Conza, J., González. A., Latorre Rapela, M., Turino, L., Ibáñez, M. & Iacona, V.

MacDonald, B. (1997). The population genetics of fungi: Tools and techniques.

Martinez Culebras P., Barrio, E., García M. & Querol A. (2000). Identification of

Tomoyasu. I. Cultivation of fungus, isolation and purification of pigment. *Journal of the American Chemical Society*, Vol.79, No.21, pp. 5725-5726, ISSN 0002-

(2007). Detección de variabilidad genética en aislamientos de *Cercospora kikuchii* contaminantes de un mismo sembradío de soja. *Revista Argentina de Microbiología*,

*Colletotrichum* species responsible for anthracnose of strawberry based on the

(9th edition), John Wiley & Sons, ISBN 978-0471878766, USA

*BioEssays*. Vol.20, No.8, pp. 652–659, ISSN 0265-9247

*Phytopathology*, Vol.87, No.4, pp. 448-453, ISSN 0031-949X

la provincia de Santa Fe (Argentina): variabilidad genética y producción de cercosporina *in vitro*. *Revista Iberoamericana de Micología*, Vol.25, pp. 237-241, ISSN

culture by medium and temperature manipulation. *Phytopathology*, Vol.79, No.2,

during conidiogenesis in *Cercospora kikuchii*. *Mycologia*, Vol.83, No.6, pp. 752-757,

Chapman & Hall/CRC, ISBN 978-1420079333, England

Centraalbureau voor Schimmelcultures, The Netherlands

85198-027-9, England

ISSN 0027-5514

1130-1406

7863

*Pathology*, Vol.13, No.2, pp. 157-164

ermedades/20320\_051207\_enfe.htm

pp. 213-219, ISSN 0031-949X

Hall, ISBN 9780138341947, England

Vol.39, No.1, pp. 11-14, ISSN 1851-7617

internal transcribed spacers of the ribosomal region. *FEMS Microbiology Letters*, Vol. 189, No.1, pp 97-101, ISSN 0378-1097


0/programas/dma/Informe\_diario/2003/infogra\_2003-12-05.pdf


http://www.ellitoral.com/ index.php/diarios/2007/04/07/laregion/REG-11.html


**6** 

*USA* 

**Pathogen Infection** 

Robert G. Upchurch

**Soybean Fatty Acid Desaturation Pathway:** 

**Responses to Temperature Changes and** 

*Agricultural Research Service-US Department of Agriculture, Raleigh, NC* 

Soybean [Glycine max (L.) Merr] is the largest oilseed crop produced and consumed worldwide, accounting for 58% of the world oilseed production (SoyStats, 2011), yet the oil produced from most available cultivars is still lacking in several quality characteristics. For example, the oil is too low in oleate and/or too high in linolenate content with resulting negative impacts on oil stability and human nutrition. Three fatty acid metabolism enzymes, the stearoyl-acyl carrier protein-desaturases (encoded by the *GmSACPD* genes), the omega-6 desaturases (*GmFAD2s*), and the omega-3 (*GmFAD3s*) desaturases largely determine the relative degree of unsaturated fatty acids and the content of the C18 fatty acids stearate (18:0), oleate (18:1), linoleate (18:2), and linolenate (18:3) in vegetative and seed lipids. In vitro studies have shown that it is possible to redesign soluble fatty acid desaturases from plants for altered fatty acid substrate and double bond position (Cahoon et al., 1997, Whittle et al., 2005) and in that way potentially alter the fatty acid content of plant lipids. Since the fatty acid composition of seed lipid is such an important determinate of oil quality, intensive efforts have also been mounted to select advantageous desaturase alleles (Wilson et al., 2001, Rajcan et al., 2005) and to manipulate molecularly desaturase expression and activity (Buhr et al., 2002), the goal being to produce elite soybean varieties with enhanced oil traits for the

Both field and growth chamber experiments have shown that the fatty acid composition in soybean tissues is responsive to environmental temperature. In field studies, temperatures during the growing season affected seed linolenic content most clearly (Hou et al., 2006). Experiments to model climate change by increasing temperatures and [CO2] in controlled environment chambers (Thomas et al., 2003) showed that exposure to increasing [CO2] had no measurable effect, but higher temperatures (greater than 32/22oC day/night) reduced total seed oil concentration while oleate increased and linolenate decreased with increasing temperature. Transcripts of β-glucosidase, a gene expressed during seed development, was detected in seeds grown at 28/18oC but not detected in seeds grown at 40/30oC. This observation suggested that one mechanism by which climate change may affect soybean seed development is through the regulation of gene transcription. The ability to adjust membrane lipid fluidity by changing the levels of unsaturated fatty acids is provided mainly by the regulated activity of fatty acid desaturases (Iba 2002). Through this

**1. Introduction** 

needs of industry and for improved human nutrition.

Yeh, C. & Sinclair, J. (1980). Sporulation and variation in size of conidia and conidiophores among five isolates of *Cercospora kikuchii*. *Plant Disease*, Vol.64, No.4, pp. 373-374, ISSN 0191-2917
