Phenotypic plasticity of grain yield and related traits in maize inbreds and hybrids grown under constrasting water regimes

Phenotypic plasticity (PP) refers to the variation range of a trait in response to changes in the environment. Traits with low PP are classified as stable, whereas those with high PP are considered plastic. The objective of current research was to evaluate PP variation in grain yield (GY) and related traits among maize inbreds (I) and hybrids (H) grown under high (WW) and low (WD) water availabilities and compare it with our previous reports for N stress. Measured traits were thermal time to 50% anthesis (TTA) and silking (TTS), the anthesis-silking interval in days (ASID) and in TT (ASITT), plant height (Ph), prolificacy (Pr), GY, kernel numbers (KN), and kernel weight (KW). Data were normalized respect to the median value of each genotype group and PP computed as the difference between percentiles 90% (P90) and 10% (P10). As previously registered for N stress, WW data corresponded to P90 and WD to P10, except for ASIs (opposite trend). I and H did not differ in PP only for Ph, KW and ASITT. A large plasticity (PP>1) was verified (i) for ASIs, GY and KN in response to water availability, and (ii) only for ASIs in response to N availability.EEA San JuanFil: Ruiz, Mónica Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; ArgentinaFil: D'Andrea, Karina Elizabeth. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones, Científicas y Técnicas; ArgentinaFil: Otegui, María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Departamento de Ecofisiología; Argentina. Consejo Nacional de Investigaciones, Científicas y Técnicas - Universidad de Buenos Aires. Facultad de Agronomía (CONICET- FAUBA); Argentin

Antagonistic capacities of Trichoderma species and their mass multiplication with agricultural wastes

El objetivo de esta investigación fue aislar y caracterizar cepas de Trichoderma nativas de Misiones (Argentina)explorando sus capacidades antagónicas y su multiplicación masiva utilizando diferentes residuos agroindustriales.Quince cepas nativas de Trichoderma spp. fueron aisladas de muestras de suelo. Estos aislamientos secaracterizaron mediante observaciones morfológicas y moleculares basados en secuencias de ADN de la regiónespaciadora transcrita interna del ADNr. Las cepas de Trichoderma spp. fueron identificadas como T. koningiopsis,T. harzianum, T. pleuroticola y T. brevicompactum. Estas cepas mostraron actividades antagónicas in vitro contraAlternaria sp., Fusarium sp. y Botrytis sp.. T. koningiopsis LBM 090, LBM 091, LBM 092 y LBM 098, T. pleuroticolaLBM 097 y T. harzianum LBM 096 presentaron una inhibición del crecimiento micelial mayor del 50% y un índicede antagonismo entre 3 y 4 contra los fitopatógenos ensayados. La cáscara de arroz y el pulido del arroz fueronlas combinaciones más adecuadas para la multiplicación de T. harzianum LBM 096.The aim of this research was to isolate and characterize Trichoderma native strains from Misiones (Argentina) exploring their antagonistic capacities to phytopatogens fungi and their mass multiplication using different agricultural wastes. Fifteen native strains of Trichoderma spp. were isolated from soil samples. These isolates were characterized via morphological observations and molecular phylogenetic analysis based on DNA sequences of the rDNA internal transcribed spacer region. The Trichoderma native strains were identified as T. koningiopsis, T. harzianum, T. pleuroticola and T. brevicompactum. All strains showed antagonistic activities in vitro against Alternaria sp., Fusarium sp. and Botrytis sp. T. koningiopsis LBM 090, LBM 091, LBM 092, and LBM 098 strains, T. pleuroticola LBM 097 and T. harzianum LBM 096 presented radial mycelial growth inhibition higher than 50% and antagonism index between 3 and 4 against the phytopathogens assayed. Among the different substrate sources evaluated, rice husk and rice polishing were the most suitable combination for mass multiplication of T. harzianum LBM 096.Fil: Sadañoski, Marcela Alejandra. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Gutierrez Brower, Gimena. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Castrillo, María Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Lopez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Ojeda, Paola. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Zapata, Pedro Dario. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Villalba, Laura Lidia. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Otegui, Monica Beatriz. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentin

Phenotypic plasticity of maize grain yield and related secondary traits: Differences between inbreds and hybrids in response to contrasting water and nitrogen regimes

Correct characterization of heritability and phenotypic plasticity (PP) is critical for breeding purposes. The latter refers to the variation range of a trait in response to changes in the environment and has been assessed as the difference between percentiles 10th (P10) and 90th (P90) of each trait, which does not reflect below the median (P50) variations to the same extent as the above the median ones. This inconsistency may affect the classification of stable (low PP) or plastic (high PP) given to traits, as well as their relative ranking and PP relationship with heritability. The objectives of current research were to evaluate corrected PP (PPC) variation in grain yield (GY) and related secondary traits among contrasting maize genotypic groups (inbreds and hybrids) grown under contrasting water regimes (WR) and nitrogen (N) availabilities. The relationship between PPC and broad-sense heritability (H2) was also assessed. Field experiments were conducted during three (N) or seven (WR) growing seasons at two mid-latitude environments of Argentina. Measured traits were days and thermal time to 50% anthesis (A50 and TTA) and to 50% silking (S50 and TTS), the anthesis-silking interval in days (ASID) and in TT (ASITT), plant height (Ph), prolificacy (Pr), GY, kernel numbers (KN), and kernel weight (KW). Values for percentiles 10th (P10), 50th (P50) and 90th (P90) of each trait were identified for each treatment combination. P50 was set to 1, and values obtained for P10 and P90 were expressed as ratios with P50. P10 was corrected (P10C= P50 – P50/P10) to reflect the below P50 variations to the same extent as those above P50. Corrected PP was estimated as PPC= P90 - P10C. P90 values of all traits corresponded to non-stressed plots whereas P10C values corresponded to stressed plots, except for ASIs (opposite trend). A large plasticity (PPC>mean PPC) was usually verified for ASIs, GY and KN. Mean inbreds PPC had a larger variation than mean hybrids PPC (+19% for WR and +29% for N), except for GY under contrasting WR (hybrids > inbreds). A common trend across all evaluated traits was the markedly larger effect on PPC of P10C than of P90, in agreement with the predominant representation of stressful conditions by the former and in contrast to previous studies where no correction was performed on P10. Our results demonstrated the lack of relationship between H2 and PP and improved current knowledge about the importance of environment modulation on PP of most expansion-related and production traits, highlighting the relevance of the evaluated resource (water or N) as well as of the genotypic group (hybrids or inbreds) on final phenotype expression.EEA PergaminoFil: Ruiz, Mónica Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; ArgentinaFil: D'Andrea, Karina Elizabeth. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones, Científicas y Técnicas; ArgentinaFil: Otegui, María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Departamento de Ecofisiología; Argentina. Consejo Nacional de Investigaciones, Científicas y Técnicas - Universidad de Buenos Aires. Facultad de Agronomía (CONICET- FAUBA); Argentin

Amplification of microsatelite markers in peltophorum dubium (spreng.) Taub (caña fistola) andenterolobium contortisiliquum (vell.) (timbo), using koompassia malaccensis benth. andenterolobium cyclocarpum (jacq.) griseb as primers

La fragmentación del hábitat es una realidad global, y muy presente en la Selva paranaense. Entre las especies vulnerables y/o amenazadas por la fragmentación del hábitat, en la Selva paranaense, podemos mencionar a Peltophorum dubium (Caña fístula) y Enterolobium contortisiliquum (Timbó), que particularmente en Misiones, se encuentran entre las de mayor interés para la industria forestal, consideradas también, como especies multipropósitos. No obstante, un uso sostenible de estas especies depende del manejo de la diversidad de especies de árboles presentes en paisajes y la variación genética dentro de estas. En Argentina no existe información acerca de la calidad genética que se conjugue con las características fenotípicas de dichas especies. En este sentido, los microsatélites son herramientas muy útiles para estudiar la diversidad genética y la estructura de las poblaciones. El objetivo del presente trabajo fue lograr la amplificación inter-específica de regiones de microsatélites de E. contortisiliquum, utilizando cebadores diseñados para E. cyclocarpum, y de P. dubium, utilizando cebadores diseñados para Koompassia malaccensis. Los resultados obtenidos confirmaron la transferibilidad de los cebadores utilizados para E. contortisiliquum y P. dubium, permitiendo amplificar regiones microsatélites de las especies estudiadas en poblaciones Argentinas. Este el primer estudio en Argentina que presenta microsatélites candidatos para E. contortisiliquum y P. dubium, que podrían ayudar en la caracterización del germoplasma.The habit fragmentation is a global reality, and very present in the Atlantic Forest. Among the species vulnerable and / or threatened by habitat fragmentation, in the Atlantic Forest, we can mention Peltophorum dubium (Cañafistula) and Enterolobium contortisiliquum (Timbó), which particularly in Misiones, are among the most interest for the forest industry, considered as well as, multipurpose species. However, a sustainable use of these species depends on the management of the diversity of tree species present in landscapes and the genetic variation within them. In Argentina, there is no information about the genetic quality correlated with the phenotypic characteristics of these species. In this sense, microsatellites are very useful tools to study genetic diversity and the structure of populations. The aim of the present work was to achieve the inter- specific amplification of microsatellite regions in E. contortisiliquum, using primers designed for E. cyclocarpum, and in P. dubium, using primers designed for Koompassia malaccensis. The obtained results confirmed the transferability of the primers used for E. contortisiliquum and P. dubium, amplifying microsatellites of the species under study for Argentina ecosystem.This being the first report in Argentina, which presents microsatellite candidates for E. contortisiliquum and P. dubium, which could help in germplasm characterization.Fil: Niella, Fernando Omar. Universidad Nacional de Misiones; ArgentinaFil: Rocha, Sandra Patricia. Universidad Nacional de Misiones; ArgentinaFil: Ojeda, Paola. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Petruszynski, Guido Andrés. Universidad Nacional de Misiones; ArgentinaFil: Zapata, Pedro Dario. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Otegui, Monica Beatriz. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentin

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field