Characterization of potato parents based on combining ability and heterosis for searching resistance to Phytophthora infestans

Controlar efectivamente a Phytophthora infestans, deviene de seleccionar genotipos con capacidad de transmitir resistencia. Con el objeto de caracterizar progenitores de papa en base a aptitud combinatoria y heterosis para resistencia a P. infestans, se cruzaron seis variedades (Libertas, Jaspe, Chotañawi, Pollerita, Robusta e INRA 92T.114.76). Quince familias de tubérculos de segunda generación clonal, obtenidas, fueron inoculadas con P. infestans en Balcarce (Buenos Aires, Argentina) y evaluadas bajo diseño en bloques completos aleatorizados con dos repeticiones. Se midió área bajo la curva del progreso de la enfermedad (AUDPC). Se estimó Aptitud Combinatoria (AC) general y específica, heterosis media, heterobeltiosis, heterosis específica (Hs) y heredabilidad en sentido amplio (H2) y estricto (h2). La AC fue significativa. El progenitor Robusta disminuyó la enfermedad estimada por AUDPC, el valor negativo grande de AC específica señaló mejor híbrido a Robusta x Chotañawi. Un tercio de las cruzas expresaron aditividad en todos los niveles de heterosis. Los valores de Hs manifestaron equivalencia con el porcentaje de disminución del AUDPC. Las heredabilidades (H2=0,63 y h2=0,54) indicaron que la selección por bajo AUDPC puede ser efectiva. El progenitor Robusta y la cruza Robusta x Chotañawi, conformaron los genotipos superiores recomendados para transferir resistencia a P. infestans.The efficient control of Phytopthora infestans results from the selection of genotypes with the capacity of transferring resistance. In order to characterize potato parents based on combining ability and heterosis for their resistance to P. infestans, six parents were crossed (Libertas, Jaspe, Chotañawi, Pollerita, Robusta and INRA 92T.114.76). The 15 tuber families of second clonal generation obtained were inoculated with P. infestans in Balcarce (Buenos Aires, Argentina) and evaluated under randomized complete block design with two replicates. Area Under Disease Progress Curve (AUDPC) was recorded for each genotype; general and specific combining ability, average heterosis, heterobeltiosis, specific heterosis and broad-sense (H2) and narrow (h2) heritability were estimated. Combining ability was significant. The Robusta parent reduced the disease estimated by AUDPC; Robusta x Chotañawi was the best hybrid, as observed by the high negative value of specific combining ability. One third of the crosses expressed significant additive effects for all levels of heterosis. Hs values showed equivalence with the percent reduction of AUDPC. The obtained heritabilities (H2=0.63 and h2=0.54) indicated that selection based on the low AUDPC values can be effective. Robusta parent and Robusta x Chotañawi cross are good genotypes for transmitting resistance to P. infestans.Fil: Andrade, Alberto Juan. Universidad Nacional de JujuyFil: Capezio, Silvia Beatriz.Fil: Huarte, Marcelo Atilio

Caracterización de progenitores de papa en base a aptitud combinatoria y heterosis para la búsqueda de resistencia a Phytophthora infestans

The efficient control of Phytopthora infestans results from the selection of genotypes with the capacity of transferring resistance. In order to characterize potato parents based on combining ability and heterosis for their resistance to P. infestans, six parents were crossed (Libertas, Jaspe, Chotañawi, Pollerita, Robusta and INRA 92T.114.76). The 15 tuber families of second clonal generation obtained were inoculated with P. infestans in Balcarce (Buenos Aires, Argentina) and evaluated under randomized complete block design with two replicates. Area Under Disease Progress Curve (AUDPC) was recorded for each genotype; general and specific combining ability, average heterosis, heterobeltiosis, specific heterosis and broad-sense (H2) and narrow (h2) heritability were estimated. Combining ability was significant. The Robusta parent reduced the disease estimated by AUDPC; Robusta x Chotañawi was the best hybrid, as observed by the high negative value of specific combining ability. One third of the crosses expressed significant additive effects for all levels of heterosis. Hs values showed equivalence with the percent reduction of AUDPC. The obtained heritabilities (H2=0.63 and h2=0.54) indicated that selection based on the low AUDPC values can be effective. Robusta parent and Robusta x Chotañawi cross are good genotypes for transmitting resistance to P. infestans.Controlar efectivamente a Phytophthora infestans, deviene de seleccionar genotipos con capacidad de transmitir resistencia. Con el objeto de caracterizar progenitores de papa en base a aptitud combinatoria y heterosis para resistencia a P. infestans, se cruzaron seis variedades (Libertas, Jaspe, Chotañawi, Pollerita, Robusta e INRA92T.114.76). Quince familias de tubérculos de segunda generación clonal, obtenidas, fueron inoculadas con P. infestans en Balcarce (Buenos Aires, Argentina) y evaluadas bajo diseño en bloques completos aleatorizados con dos repeticiones. Se midió área bajo la curva del progreso de la enfermedad (AUDPC). Se estimó Aptitud Combinatoria (AC) general y específica, heterosis media, heterobeltiosis, heterosis específica (Hs) y heredabilidad en sentido amplio (H2) y estricto (h2). La AC fue significativa. El progenitor Robusta disminuyó la enfermedad estimada por AUDPC, el valor negativo grande de AC específica señaló mejor híbrido a Robusta x Chotañawi. Un tercio de las cruzas expresaron aditividad en todos los niveles de heterosis. Los valores de Hs manifestaron equivalencia con el porcentaje de disminución del AUDPC. Las heredabilidades (H2=0,63 y h2=0,54) indicaron que la selección por bajo AUDPC puede ser efectiva. El progenitor Robusta y la cruza Robusta x Chotañawi, conformaron los genotipos superiores recomendados para transferir resistencia a P. infestans

Caracterización de progenitores de papa en base aaptitud combinatoria y heterosis para la búsqueda deresistencia a Phytophthora infestans = Characterization of potato parents based on combining ability and heterosis for searching resistance to Phytophthora infestans

Controlar efectivamente a Phytophthora infestans, deviene de seleccionar genotipos con capacidad de transmitir resistencia. Con el objeto de caracterizar progenitores de papa en base a aptitud combinatoria y heterosis para resistencia a P. infestans, se cruzaron seis variedades (Libertas, Jaspe, Chotañawi, Pollerita, Robusta e INRA92T.114.76). Quince familias de tubérculos de segunda generación clonal, obtenidas, fueron inoculadas con P. infestans en Balcarce (Buenos Aires, Argentina) y evaluadas bajo diseño en bloques completos aleatorizados con dos repeticiones. Se midió área bajo la curva del progreso de la enfermedad (AUDPC). Se estimó Aptitud Combinatoria (AC) general y específica, heterosis media, heterobeltiosis, heterosis específica (Hs) y heredabilidad en sentido amplio (H2) y estricto (h2). La AC fue significativa. El progenitor Robusta disminuyó la enfermedad estimada por AUDPC, el valor negativo grande de AC específica señaló mejor híbrido a Robusta x Chotañawi. Un tercio de las cruzas expresaron aditividad en todos los niveles de heterosis. Los valores de Hs manifestaron equivalencia con el porcentaje de disminución del AUDPC. Las heredabilidades (H2=0,63 y h2=0,54) indicaron que la selección por bajo AUDPC puede ser efectiva. El progenitor Robusta y la cruza Robusta x Chotañawi, conformaron los genotipos superiores recomendados para transferir resistencia a P. infestans.The efficient control of Phytopthora infestans results from the selection of genotypes with the capacity of transferring resistance. In order to characterize potato parents based on combining ability and heterosis for their resistance to P. infestans, six parents were crossed (Libertas, Jaspe, Chotañawi, Pollerita, Robusta and INRA 92T.114.76). The 15 tuber families of second clonal generation obtained were inoculated with P. infestans in Balcarce (Buenos Aires, Argentina) and evaluated under randomized complete block design with two replicates. Area Under Disease Progress Curve (AUDPC) was recorded for each genotype; general and specific combining ability, average heterosis, heterobeltiosis, specific heterosis and broad-sense (H2) and narrow (h2) heritability were estimated. Combining ability was significant. The Robusta parent reduced the disease estimated by AUDPC; Robusta x Chotañawi was the best hybrid, as observed by the high negative value of specific combining ability. One third of the crosses expressed significant additive effects for all levels of heterosis. Hs values showed equivalence with the percent reduction of AUDPC. The obtained heritabilities (H2=0.63 and h2=0.54) indicated that selection based on the low AUDPC values can be effective. Robusta parent and Robusta x Chotañawi cross are good genotypes for transmitting resistance to P. infestans.EEA BalcarceFil: Andrade, Alberto Juan. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; ArgentinaFil: Capezio, Silvia Beatriz. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Huarte, Marcelo Atilio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentin

Biochemical markers involved in the horizontal resistance to phytophthora infestans to assist potato breeding programs

Potato Late Blight is the main pathogen, which affect potatoes. Due to unavailability of effective chemical control methods and the intensive use of fungicides, which leads to high environmental and production costs, the introduction of resistant cultivars represents a safe strategy to reduce the negative aspects of the disease effects. The sources of horizontal resistance to Late Blight in the Argentinean Potato Breeding Program have been varied. One of the interesting species to evaluate is Solanum tarijense since its adaptation to long days is promissory, producing tubers of good size and aspect. Many studies have demonstrated that the expression of pathogenesis related proteins (PR) differ with the level of disease resistance in potato cultivars. These results suggest that the constitutive or inducible expression of PR proteins may contribute to the resistance to P. infestans. In this study, the enzymatic activity of different PR proteins in the specie S. tarijense was measured. Two potato clones with different levels of resistance were used. These clones were more resistant to Late Blight than Bintje and Pampeana INTA cultivars, used as control. The activity of glucanases, chitinases, peroxidases and poliphenoloxidases were 8, 1.5, 2.5, and 3 times higher respectively, in S. tarijense than in Bintje and Pampeana INTA. These results together with future studies on the interaction S. tarijense-P. infestans, will allow the introgression of S. tarijense genes in breeding programs and the use of some PR proteins as biochemical markers to assist selection towards the identification of horizontal resistant cultivars.Fil: Wolski, Erika Alejandra. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Korgan, Samanta. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Capezio, Silvia Beatriz. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Huarte, Marcelo Atilio. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin

Eco-physiological yield determinants in four potato genotypes grown in a temperate environment

The eco-physiological yield determinants of four potato genotypes suitable for processing into French fries were studied. Field trials were carried out during the growing seasons 2016/17 and 2017/18 at Balcarce, Argentina (−37.85 S, −58.19 W). Genotypes, identified as Bal1, Bal2, Bal3 and Bal4, have growing cycles of 95–105, 100–110, 110–120, and 120–130 days after emergence, respectively. Intercepted photosynthetic active radiation (PARint), radiation use efficiency (RUE), harvest index (HI) and tuber yield were evaluated during both growing seasons. Bal4 achieved the highest dry matter tuber yield in both growing seasons, with 1412 and 1879 g mˉ² for 2016/17 and 2017/18, respectively. Due to a combination of a high PARint and RUE values, tuber dry matter in Bal4 was 20–30 % higher than that achieved by other genotypes. PARint throughout the growing cycle was 1025 and 1121 MJ mˉ² for Bal4, for 2016/17 and 2017/18 seasons, respectively; these values were 10–22 % higher than those observed for the other genotypes. RUE was 1.66 and 2.02 g MJˉ1 for Bal4 in 2016/17 and 2017/18 growing seasons, respectively, these values are 14–18 % higher than those observed for the other genotypes. HI varied between 0.81 and 0.87 for all genotypes, in both seasons. PARint, and RUE were the two most critical yield determining factors that explained the differences in tuber dry matter yield between the potato genotypes. Bal4 showed highest yields due to a particular combination of high PARint and high RUE, not reported in the literature, so far. These results could contribute to improve early selection in future breeding programs, to better adjust growth models and to establish specific management strategies for a particular genotype.Fil: Santos, Diego Hugo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Andrade, Fernando Héctor. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Capezio, Silvia Beatriz. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Caldiz, Daniel Osmar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Mccain Foods Limited; Canadá. Global Agronomy R&D; ArgentinaFil: Monzon, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

Solanum tarijense reaction to P. infestans and the role of plant defense molecules

Late blight is the main disease of potatoes around the world. Because of the difficulties in applying effective control methods, the introduction of resistant cultivars represents a safe strategy. The potato species Solanum tarijense represents an attractive resistance source as its adaptation to long days is promissory, producing tubers of good size and aspect. Deposition of structural compounds like lignin and callose were described as a non‐specific resistance mechanism. In this work, we measured polyphenoloxidases (PPO) and peroxidases (POX) activities and the accumulation of phenols, lignin and callose and their correlation with the resistance levels of S. tarijense. Clones Oka 6320.9 and Oka 5632.11 showed low infection rates and these were correlated with a higher accumulation of phenols, lignin and callose and a strong induction of PPO and POX activities. However, in highly infected clones, a lower or no accumulation of these compounds was observed. These results demonstrate a correlation between the amount of defence molecules and the resistance levels according to the detached‐leaf assay. However, more field experiments are required to validate these results.Fil: Korgan, Samanta. Universidad Nacional de Mar del Plata; ArgentinaFil: Wolski, Erika Alejandra. Universidad Nacional de Mar del Plata, Facultad de Ingeniería, Departamento de Ingeniería Química y en Alimentos; ArgentinaFil: Cicore, Pablo Leandro. Universidad Nacional de Mar del Plata; ArgentinaFil: Suarez, Patricia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Capezio, Silvia Beatriz. Instituto Balcarce.; ArgentinaFil: Huarte, Marcelo Atilio. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin