Influencia de las interacciones del genotipo y ubicación sobre el aceite, los ácidos grasos y las propiedades agronómicas del maní

An enhanced adaptation to specific environmental conditions could provide higher seed quality and quantity from groundnuts. In this investigation, nine groundnut genotypes and two controls were evaluated for morphological and oil traits in two different Mediterranean locations. The traits of shelling percentage and pod yield indicated significant differences among the genotypes. The highest pod yield was observed for ACG 154 from the subsp. hypogaea var. hypogaea and ACG 107 from the subsp. fastigiata var. vulgaris in the locations of Adana and Antalya, respectively. The genotype ACG 154 also had about 60 g of 100-seed weight, which is desirable for commercial production as a Runner commercial type. Significant differences were recorded for oil yield, palmitic, oleic and linoleic acids in both locations among the genotypes studied. The groundnut genotypes were further evaluated with allele-specific PCR markers for possible SNP mutations in the ahFAD2A and ahFAD2B genes for high-oleic mutants. ACG 14, ACG 154 and ACG 156 had the mutant ahFAD2A allele, while no ahFAD2B allele mutation was found. The statistical model GGE bi-plot was used to identify the ideal and representative location for each genotype according to pod yield performance. The genotypes ACG 107 and ACG 116 presented the highest oil yield and were relatively stable across locations. Therefore, they should be evaluated as candidates for cultivar releases in the two studied climatic areas. In addition, the selected desirable genotypes in this study can be used as parents in hybridization programs to develop populations for future releases.El maní, teniendo una mejor adaptación a las condiciones ambientales específicas, podría proporcionar una mayor calidad y cantidad de semillas. En esta investigación, nueve genotipos de cacahuete y dos controles procedentes de dos lugares diferentes del Mediterráneo se evaluaron en relación a las características morfológicas y al aceite. Los rasgos de porcentajes de descascarillado y la producción de la vaina indicaron diferencias significativas entre genotipos así como del rendimiento de la vaina. El rendimiento de vaina más alto se observó en ACG 154 a partir de la subsp. hypogaea var. hypogaea y ACG 107 de subsp. fastigiata var. vulgaris en las ubicaciones de Adana y Antalya, respectivamente. El genotipo ACG 154 también tenía aproximadamente 60 por ciento en peso de semilla que es un valor deseable para la producción comercial un mercado tipo. Se registraron diferencias significativas para el rendimiento de aceite, para los ácidos palmítico, oleico y linoleico en ambos lugares entre los genotipos. Se evaluaron además, los marcadores de PCR específicos de alelo para posibles mutaciones de SNP en genes ahFAD2A y ahFAD2B para mutantes de alto contenido de ácido oleico. ACG 14, ACG 154 y ACG 156 tenían el alelo ahFAD2A mutante mientras que no había mutación del alelo ahFAD2B. El modelo estadístico GGE biplot se utilizó para identificar la ubicación ideal y representativa para cada genotipo en el rendimiento de la cápsula. Los genotipos, ACG 107 y ACG 116, tuvieron mayor rendimiento de aceite y eran relativamente estables en todas las ubicaciones, por lo que deberían evaluarse como candidatos para extender los cultivares en las dos áreas climáticas estudiadas. Además, los genotipos deseables seleccionados en este estudio se pueden utilizar como padres en programas de hibridación para desarrollar poblaciones para futuras liberaciones

Identification of rust resistance in groundnut using a validated SSR marker

Groundnut (Arachis hypogaea L.) is an important crop cultivated in over 100 countries in the world. The rust disease of groundnut, caused by Puccinia arachidis Speg., can cause significant yield losses in tropical and subtropical areas. The disease affects not only seed yield but also fodder yield and quality. There are chemicals available to control rust; however, the development of resistant varieties is the most reasonable way to improve yield and quality, and to reduce the adverse effects of chemicals on the ecosystem. Characterization of germplasm diversity to identify resistant sources using traditional methods is a lengthy process and requires laborious field testing. Molecular marker-aided selection offers an alternative breeding method that is relatively easy, precise, and not affected by environmental fluctuation. In the present study, a validated SSR marker, GM1954, linked to the rust disease resistance gene was used for 256 groundnut genotypes to select rust resistance. This study reports the successful application of marker-assisted selection for further rust-resistant breeding programs in groundnut. Molecular analyses revealed that the banding pattern related to disease resistance was observed at high frequency in the variety hypogaea among the nine identified resistant genotypes in the collection. Approximately 3 % of the collection was selected for further field, greenhouse, and hybridization experiments

Molecular diagnosis to identify new sources of resistance to sclerotinia blight in groundnut (Arachis hypogaea L.)

Sclerotinia blight, caused by soil-borne fungus Sclerotinia minor Jagger, is one of the destructive diseases in groundnut. Pathogen affected plants usually displays lesions, wilt and collapse which cause high yield losses. Traditional field screening is time and resources consuming. Molecular markers associated with resistance genes offer an alternative selection technique which is relatively easy, more definite and not influenced by environmental fluctuations. In the present investigation, a marker-assisted diagnosis was done to screen 256 diverse germplasm for the presence or absence of SSR markers reported resistance or susceptibility to sclerotinia blight. One hundred and forty two genotypes from different botanical varieties were recognized as new potential sources of resistance to sclerotinia blight for field evaluation. The banding pattern related to the disease resistance is observed at high frequency in the variety vulgaris (39.4 %) and less distributed in the varieties fastigiata (38.0 %) and hypogaea (19.7 %) among the resistant genotypes in the collection. These genotypes had same banding pattern as reported for resistance germplasm. This work reports the successful application of marker-assisted diagnosis as a tool to identify resistance to sclerotinia blight in diverse collections

Validation of field resistance to late leaf spot by using a molecular marker in groundnut

Groundnut or peanut (Arachis hypogaea L.) is an important oilseed crop which is valued as a rich source of high quality edible oil, protein, minerals and vitamins. It offers nutritional and economic benefits to the consumers and farmers, respectively. However there are many biotic and abiotic constraints to groundnut production in various eco-agricultural systems. The late leaf spot (LLS) is one of the most widespread and damaging foliar diseases of groundnut and it can reduce pod and fodder yields to an extent of over 50%, also affects adversely quality of seeds. Much of the global groundnut breeding efforts therefore have been directed to develop cultivars with high yields and also incorporating genes conferring resistance or tolerance to LLS disease. Integration of molecular marker aided selection with field based breeding is important to enhance the precision and speed of developing peanut cultivars with LLS resistance. In this perspective, many LLS resistance-related molecular markers have been developed to aid in the selection processes. The SSR marker, PM 384, is one of these markers and showed significant association with LLS resistance (Shoba et al. 2012, Euphytica, 188:265-272). The groundnut collection including 39 genotypes was employed for validating LLS resistance-linked marker (PM 384) and identifying resistant individuals. These genotypes were evaluated in the field with nine point disease scale to screen the genotypes for sources of resistance to LLS. Plants with a disease score of 1-3 and 6-9 were designated as being resistant and susceptible, respectively. After field evaluation, field scored genotypes were validated by LLS resistance using the linked marker, PM 384

Characterization of groundnut (Arachis hypogaea L.) collection using quantitative and qualitative traits in the Mediterranean Basin

Abstract This study was conducted to determine the genetic diversity and relationship among 256 groundnut genotypes of which 132 belong to subspecies (Subsp.) Arachis hypogaea L. and 124 to Subsp. Arachis fastigiata L. The collection was evaluated for eight quantitative and five qualitative traits during three consecutive years under Mediterranean climate conditions. Coefficient of variation (CV) significantly differed among the genotypes for all the studied quantitative traits ranged from 9.10 to 33.98%, while the highest CV was recorded for seed yield. The subspecies, A. hypogaea L. and A. fastigiata L., displayed significant differences for quantitative traits except for numbers of pods per plant and seed yield. Principal component analyses showed that the first three principal components accounted for 68.14% variation for quantitative traits. Major traits that accounted for the variation by the three PCs include days to the first flowering, days to 50% flowering, number of pods per plant and shelling percentage. The groundnut collection also offers wide seed coat color diversity which affects the crop marketability. The information on variations in quantitative and qualitative traits identified in the present investigation provided useful genotypes which would be serving parents. These parental genotypes can be used in groundnut breeding programs to develop desirable cultivars in Mediterranean basin and globally

Topological 2-form Gravity in Four Dimensions

A kind of topological field theory is proposed as a candidate to describe the global structure of the 2-form Einstein gravity with or without a cosmological constant. Indeed in the former case, we show that a quantum state in the candidate gives an exact solution of the Wheeler-DeWitt equation. The BRST quantization based on the Batalin-Fradkin-Vilkovisky (BFV) formalism is carried out for this topological version of the 2-form Einstein gravity.Comment: 15 page

Position-Dependent Extension of π-Conjugation in D-π-A Dye Sensitizers and the Impact on the Charge-Transfer Properties

A series of five organic donor-π-bridge-acceptor (D-π-A) sensitizers is investigated within the context of their photoinduced charge-transfer properties. Thereby, the focus is set on the impact of structural modifications of the molecular architecture on the π-systems of the dyes. In particular, two different modes of systematic extension of the sensitizers’ π-systems, namely, (i) within the electron donating site and (ii) within the π-bridge, are investigated by means of steady-state and time-resolved spectroscopic methods. The photophysical studies of the molecules in solution and as deposited on Al2O3 or TiO2 films reveal that different effects on the charge-transfer characteristics evolve dependent where – within the molecular structure – the modification of the π-system is performed. Hence, π-extension of the donor sites, for instance, leads to a strong red shift of the absorption features and a variation of light-harvesting properties. Modifying the π-bridges results in a spatial decoupling of the HOMO and LUMO orbitals, which goes along with changes of the electronic coupling to TiO2. Furthermore, solution studies show that the electronic structure of the dyes governs their singlet excited-state features. As shown, the results obtained from these studies then allow important predictions about the deactivation of the excited states of these molecules adsorbed on TiO2. Finally, quantum chemical methods – among others, time-dependent density functional theory calculations – provide conclusive insight into the relationship between the electronic structure of the dyes and its impact on the photoinduced charge-transfer characteristics

Long-Range π-Conjugation in Phenothiazine-containing Donor-Acceptor Dyes for Application in Dye-Sensitized Solar Cells

Four organic donor–π-bridge–acceptor dyes containing phenothiazine as a spacer and cyanoacrylic acid as an acceptor were synthesized and tested as sensitizers in dye-sensitized solar cells (DSCs). The influence of iodide- and cobalt-based redox electrolytes on the photovoltaic device performance was investigated. In these new dyes, systematic π-conjugation was extended by inserting one or two phenothiazine moieties and investigated within the context of the resulting photoinduced charge-transfer properties. A detailed investigation, including transient absorption spectroscopy and quantum chemical methods, provided important information on the role of extended π-conjugation on the photophysical properties and photovoltaic device performance. Overall, the results showed that the extension of π-conjugation by one phenothiazine unit resulted in the best device performance owing to reduced recombination rates, whereas extension by two phenothiazine units reduced dye adsorption on TiO2 probably owing to the increase in molecular size. The performance of the dyes in DSCs was found to be a complex interaction between dye structure and size

Increasing abdominal pressure with and without PEEP: effects on intra-peritoneal, intra-organ and intra-vascular pressures

Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure

Increasing abdominal pressure with and without PEEP: effects on intra-peritoneal, intra-organ and intra-vascular pressures

Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure