CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
Not a member yet
791 research outputs found
Sort by
High sugar Eastern gamagrass (Tripsacum dactyloides L) cultivars as potential biofuel feedstock
Get PDFMaize (Zea mays L) is the leading biofuel crop in the United States. Production of ethanol from maize requires relatively high energy inputs from petroleum-based products. The net energy required for growing maize and consequent contribution to atmospheric CO2 make using maize for ethanol production inefficient. Warm season perennial grasses have excellent potential as alternative biofuel feedstocks. However, one of the drawbacks of using these grasses is their high lignin content, which restricts breakdown of cellulose into carbohydrates and sugar for fermentation into ethanol. This results in low net ethanol yield, a major challenge for biofuel production from cellulosic feedstocks. Eastern gamagrass (Tripsacum dactyloides L) is a warm season native American grass related to maize. To evaluate potential of Eastern gamagrass and gamagrass-Zea recombinant lines as a biofuel feedstock, seven varieties were analyzed for their chemical composition and fermentable sugar production. Based on total sugar yield, gamagrass-Zea recombinant cultivars Eagle Point Devil Corn and Sun Devil reached 595.8 and 456.5 mg g-1 raw biomass, respectively. Compared to the other gamagrass varieties and energy crops switchgrass and bermudagrass, these gamagrass-Zea recombinants gave a significantly higher (
Root response to temperature extremes: association mapping of temperate maize (Zea mays L)
Get PDFLittle is known about the genetic control of the root architecture of maize (Zea mays L) and its response to temperature extremes. An association mapping panel, including 32 flint and 42 dent inbred lines, was characterized for root traits. The growth of axile and lateral roots was assessed non-destructively in growth pouches at 16°C (chilling), 28°C (control) and 36°C (heat). Association mapping was done using the PKOpt mixed-model associationmapping approach. Heat slowed down the development of seedling roots to a lesser extent than chilling, but differences between the heterotic groups were observed mainly at optimal temperature. Of 1,415 AFLP markers, 70 showed significant marker-trait associations and 90 showed significant marker-trait associations with temperature interaction effects. Compared to the flint lines, the dents showed stronger growth of axile roots, especially under optimal conditions, and carried more of the trait-increasing alleles for the length of axile roots. In contrast, Benjamin the flints accumulated more root dry weight at low temperature and exclusively carried the alleles favoring tolerance to chilling. A combination of inbreds carrying alleles positive for performance under contrasting temperature conditions should lead to a complementary effect in the hybrid and would increase adaptation to a wider range of temperature
Genetic potential of S1 lines derived from native maize populations of Tamaulipas, Mexico
Get PDFThis study is designed to evaluate and select the best S1 maize top cross lines to continue their process of inbreeding. Nineteen top crosses samples were examined from three contrasting environments (two places from Tamaulipas and one place from the Central High Valleys of Mexico) during 2008. These S1 lines were derived from native populations of four ecological zones of Tamaulipas; one tester from the High Valleys was used. Some top crosses had high yield as well as favorable agronomic traits, though these varied between environments. Some had better performance in Northern Tamaulipas, mainly the tropical groups 1 and 2 that are from hot and dry climates. In the High Valleys these groups had lower yields compared with the top crosses groups 3 and 4. Group 1, the top cross of I-C3001-2915-2 with high yield in the Central and Northern Tamaulipas environments (2.4 and 5.8 t ha-1, respectively) was outstanding. In the High Valleys, the top crosses from group 3 (from the Tamaulipas Huasteca, a hot, and humid climate zone) had yields of 7.4 to 8.5 t ha-1 and from group 4, the top cross of IV-C4031-2939-5(C) yielded 8.8 t ha-1. The S1 lines being evaluated show potential for those top crosses with better grain yield and earliness, indicating good combining ability. It has been suggested that the S1 lines are better to continue the inbreeding process, planning test crosses and field assessments in the environments where they had better performance
A spatial model for sporadic tree species distribution in support of tree oriented silviculture
Get PDFThis technical note describes how a spatial model for sporadic tree species distribution in the territory of the Unione di Comuni Montana Colline Metallifere (UCMCM) was built using the Random Forest (RF) algorithm and 48 predictors, including reflectance values from ground cover - provided by satellite sensors - and ecological factors. The P.Pro.SPO.T. project - Policy and Protection of Sporadic tree species in Tuscany forest (LIFE 09 ENV/IT/000087) is currently carried out in this area with the purpose of initiating the implementation of tree oriented silviculture in the Tuscany forests. Tree oriented silviculture aims at obtaining both forest biodiversity protection and local production of valuable timber. After creating a map showing the probability of presence of sporadic tree species, it was possible to identify the most suitable areas for sporadic tree species which are under protection according to the regulation of the Tuscany Region.Using data and software provided free of charge, and applying the RF algorithm, distribution models could be developed in order to identify the most suitable areas for the application of tree oriented silviculture. This can provide a support to forestry planning that includes tree oriented silviculture, thus reducing its implementation cost
Were there significant changes in the overall condition of the CONECOFOR plots over the 1995 -2005 period?
Get PDFSince 1995 the CONECOFOR programme is collecting data on a number of attributes of forest ecosystems in 20 permanent plots in Italy. In this paper, different multivariate methods were used to detect possible changes and deviations in the overall biological and chemical-physical status of the CONECOFOR plots as compared to defined reference periods. The reference periods were set-up taking into account the data availability and were as follows: 1997-1999 for biological status; 1999-2002 for chemical-physical status. Changes of the biological conditions of the plots were identified only in a few cases over the period 2000 - 2004 and were due to low values in transparency and basal area increment of the intermediate and dominated layer. On the other hand, several changes were detected in relation to the chemical and physical status over the period 2003-2005. Some few regularities were identified: (i) change/deviations concentrated on few plots; (ii) high ozone (O3), low sulphur deposition and low precipitation were the attributes more consistently related tochanges/deviations; (iii) most deviations were due to changes in the correlation structure of the attributes; and (iv) there is no consistenttiming of change/deviations among plots. These findings emphasise the need to evaluate the data at the plot level and this indicate the importance of obtaining a time series long enough to enable plot-wise integrated analysis
Quality related traits of the maize (Zea mays L) grain: gene identification and exploitation
Get PDFDeveloping maize plants with improved kernel quality traits involves the ability to use existing genetic variation and to identify and manipulate commercially important genes. This will open opportunities for designing novel variation in grain composition and will provide the basis for the development of the next generation of specialty maize. This paper provides an overview of current knowledge on the identification and exploitation of genes affecting the composition, development, and structure of the maize kernel with particular emphasis on pathways relevant to endosperm growth and development, differentiation of starch-filled cells, and biosynthesis of starches, storage proteins, lipids, and carotenoids. The potential that the new technologies of cell and molecular biology will provide for the creation of new variation in the future are also indicated and discussed
Natural variation for BYDV resistance in maize
Get PDFWith increasing winter temperatures, Barley yellow dwarf virus (BYDV) is expected to become a prominent problem also in maize cultivation. Breeding for resistance is the best alternative to control the disease and break the transmission cycle of the virus. The objectives of our study were to (I) determine phenotypic and genotypic variation in five segregating populations of maize with respect to BYDV tolerance or resistance as well as (II) quantify the influence of BYDV infection on plant performance traits. In 2011, five segregating populations with a total of 445 genotypes were grown at two locations in Germany. Plants were inoculated with BYDV-PAV transmitted by aphids of the species Rhopalosiphum padi. We observed considerable genotypic variance for the traits virus concentration as measured by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) as well as expression of symptoms. Furthermore, heritabilities were high for the plant performance traits ear height and plant height. Correlation coefficients between all pairs of traits were significantly different from 0 (P < 0.05). Genotypes of the inoculated variant were reduced in plant height by 3 cm, ear height by 6 cm, and flowered 3 days earlier compared to genotypes of the non-inoculated variant. The results of our study suggested a high potential for breeding of BVDY resistant / tolerant maize
Arundo donax as an energy crop: pros and cons of the utilization of this perennial plant
Get PDFArundo donax (giant reed) is a rhizomatous grass widely found in temperate and subtropical regions. Because of its capacity to grow vigorously in marginal land, it is considered as a dangerous weed plant. However, humans contributed to the dispersion of this plant around the world because Arundo is used it for multiple purposes such as reeds in woodwind musical instruments, roof thatching and fishing rods. In recent years A. donax, due to its high biomass production has been also considered as a promising energy crop. Nevertheless, some important issues must be addressed. In fact, A. donax is a sterile plant and its propagation is based on vegetative propagation (fragmentation of rhizomes or canes) and in vitro culture, making establishing the crop on a large scale very expensive. Furthermore the geneticists cannot carry out conventional breeding programmes, so improvement will be based on ecotype selection, chemical and physical mutagenesis, and transgenesis techniques. Another aspect to consider for a massive utilization of A. donax as an energy crop consists in the scarcity of data on long-term field experiments, since the duration of the crop’s life is 12-15 years. Hence, in this short review, we will bring together the principal pros and cons of this new putative energy crop
Inter- and intra-population genetic variations in Jatropha curcas populations revealed by inter-simple sequence repeat molecular markers
Get PDFInter simple sequence reaction (ISSR) was employed to assess diversity in six Jatropha populations that were collected in Malaysia, Indonesia, the Philippines and India. A total of 144 accessions (24 accessions per population) were selected and analysed with 10 ISSR primer combinations to generate a total of 143 polymorphic fragments. The number of bands generated per primer varied from 4 to 27. The percentages of polymorphic bands for the Indonesia1, Indonesia2, Malaysia1, Malaysia2, Philippines and India Jatropha populations were 54.6, 59.4, 46.2, 53.2, 60.8 and 56.4%, respectively, with an average of 55.1%. The Nei’s total genetic diversity (HT), the intra-populations genetic diversity (HS) and the coefficient of genetic differentiation (GST) were 0.1136, 0.0989 and 0.1295, respectively. The coefficient of genetic differentiation (GST) was 0.1295, which indicated a frequency of approximately 13% in genetic variations observed in the inter-Jatropha populations, while an 87% variation corresponded to the intra-Jatropha populations. Analysis of molecular variance (AMOVA) analysis indicated highly significant (p = 0.001) genetic differences among the six Jatropha populations. An UPGMA dendrogram was constructed, and the Jatropha populations were grouped into four major clusters at a coefficient level of 0.28. The genetic similarities between the populations ranged from 0.31 to 0.25. The principal component analysis showed a relatively similar grouping of the populations. To obtain high heterotic responses, hybridisation should be made between the two distant populations of Malaysia 1 and Indonesia1
The effects of foliar application of ascorbic acid (vitamin C) on physiological and biochemical changes of corn (Zea mays L) under irrigation withholding in different growth stages
Get PDFTo study the effects of ascorbic acid foliar application and limited irrigation in different growth stages on physiological and biochemical changes of corn, an experiment was conducted in Varamin, Iran during the growing season of 2012. The experimental design was randomized complete blocks in split plots arrangement with three replications. Main plots included four different levels of irrigation (complete irrigation, irrigation withholding at 8-leaf stage, irrigation withholding at silks appearance stage and irrigation withholding at both 8-leaf stage and silks appearance stages) and different concentration of foliar application of ascorbic acid (vitamin C) (0, 75, and 150 ppm) were allocated to subplots. The results showed that irrigation withholding conditions in different growth stages significantly decreased seed yield, RWC and total chlorophyll but by contrast increased proline content, antioxidant enzymes activity. Ascorbic acid foliar application in irrigation with holding in different growth stages had positive effect on all attributes in this experiment. In general, the results of the present study indicate that usage of AsA reduces the harmful effects of water deficit stress and increases resistance to drought stress in corn plant