CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
Not a member yet
791 research outputs found
Sort by
Infectivity of Mediterranean native Entomopathogenic Nematodes (Steinerne ¬matidae and Heterorhabditidae) from natural habitats in relation to temperature.
Get PDFThe infectious activity of 15 Steinernema and Heterorhabditis strains of Entomopathogenic Nematodes (EPNs), belonging to 5 species (Steinernema feltiae, S. affine, S. apuliae, S. ichnusae and H. bacteriophora) collected from natural habitats (meadows, coasts and woods) in Southern Italy was compared in laboratory bioassays against Galleria mellonella larvae. Infectivity was determined by 2 larval mortality rate assays in relation to different temperature values. In the first experiment the percentage of larval mortality was recorded after a 72-hr exposure period to the EPNs Infective Juveniles (IJs) at 6 temperatures between 10 and 35°C, at intervals of 5°C, using IJs in aqueous suspension. The second bioassay was performed to compare the infectivity at 3 relatively low temperature values (6-10-14°C), using IJs in 2 different suspensions (aqueous and gel); the percentage of larval mortality was recorded every 72 hrs for 12 days after exposure to IJs. In the first experiment S. feltiae, S. ichnusae and S. affine strains showed the best performances at temperature values 10, 15, 20 and 25°C, while H. bacteriophora and S. apuliae showed the best results at 30 and 35°C. In the second test S. feltiae, S. ichnusae and S. affine strains demonstrated a better cold-infectivity (at 6-10-14°C) than H. bacteriophora and S. apuliae strains. IJs in the water suspension killed the Galleria larvae quicker than those in the gel. The gel suspension keeps nematodes more safe and active than the water one
Bumblebees in natural and agro-ecosystems at different altitudes from Mount Etna, Sicily (Hymenoptera Apidae Bombinae): long-term faunistic and ecological observations.
Get PDFThe results of a ten-years study on bumblebee species of Mount Etna in eastern Sicily are given. The observations were carried out in natural and anthropized ecosystems at different altitudes in the Mediterranean Basal plan (0-1450 m a.s.l.) and Mountain-Mediterranean plan (1450-2100 m a.s.l.). Twelve species belonging to Bombus (2 spp.), Melanobombus (1 sp.), Megabombus (2 spp.), Thoracobombus (3 spp.) and Psithyrus (4 spp.) subgenera are recorded. In the Mountain-Mediterranean plan, rich in endemic plants from Etna and Sicily, 11 species have been recorded on plants characterised by the highest honey potential like Astragalus, Rubus, and Senecio. The most abundant species in this level are B. lapidarius decipiens and B. lucorum lucorum. In the Mediterranean Basal plan 12 species have been recorded. Among them, Bombus terrestris terrestris is always present, and B. terrestris calabricus has been recorded only at 1900 m a.s.l. Data are given on surveyed bumblebee species and subspecies, their presence in Italy, the spread in Sicily, and the plants on which the bees were observed. These data are placed in relation to the altitudinal levels and the ecological quality of the areas where the specimens were found
The interaction of drought stress and heat stress as determinant of dry matter yield and nutritional composition of maize (Zea mays L) whole-plant for silage
Get PDFThe objective of this study was to understand how abiotic factors affected dry matter (DM) yield and nutritional composition of maize whole-plant for silage. We analyzed data from maize hybrids performance trials completed at two sites (ie, Southern Piedmont and Shenandoah Valley regions) during 2011 and 2012. Data from eight maize hybrids (110 to 117 days to maturity) were tested in both sites and years. Dry matter yield and nutritional compo- sition were analyzed through mixed model analysis. Climate data were obtained from weather stations located in Blackstone and Elkton (Virginia, USA). Whole-plant DM yields varied significantly across site.years (P < 0.01), ranging from 4,556 to 15,092 kg ha-1. Dry matter (DM; P < 0.01) and crude protein (CP; P < 0.01) concentrations differed among site.years. These high variations are attributed to the low DM concentration (25.3% DM) and to the high CP concentration (10.9% CP) observed for the Southern Piedmont region in 2012. Neutral detergent fiber (NDF; P < 0.01) and acid detergent fiber (ADF; P < 0.01) were significantly different between site.years. That NDF concentration in 2012 was substantially lower for the Shenandoah Valley region (43.0% NDF) than for the Southern Piedmont region (56.6% NDF) indicates that maize crops were affected differently despite summer drought. We concluded that heat stress had a major adverse effect on kernel development in the Southern Piedmont region, but not in the Shenandoah Valley region, and that heat stress exacerbated the effects of drought reducing sub- stantially DM yields and increasing whole plant fiber concentration
Short-term drought responses by seedlings of three maizes from contrasting environments in Michoacán, Mexico
Get PDFAlterations in precipitation regimes resulting from climate change threaten countries like Mexico, where rainfed ag- riculture for subsistence is widespread. However, numerous local maizes are cultivated throughout the country’s territory originated from a substantial environmental diversity. To investigate whether an environmental specializa- tion exists, responses to drought by maizes from three sites (elevations of 689, 2379, and 3638 m) in the state of Michoacán, Mexico, were studied in a greenhouse experiment. Plants were watered every other day for 21 days since sowing. Watering was withheld during 26 d and followed by a 10 d recovery period during which watering was resumed. Environmental conditions were contrasting among the sites of origin, e.g., annual precipitation defi- cit (from an ombrotherm diagram) was 33% at the lowest site and 9% and 0.3% for the sites at higher elevations. At the greenhouse, substrate water content for the control was ca. 34% (w/w) over the course of the experiment, it decreased to 1.9% at 26 d of water withholding and recovered after resuming irrigation. Tissue water content was ca. 92% for the control and decreased by 22-33% (depending on its origin) for the droughted individuals at the peak of the drought. Dry mass was lower for droughted individuals than for the control at the end of the experi- ment. Leaf chlorophyll content tended to decrease with plant age, but did not respond to water withholding. In contrast, proline tended to increase for droughted individuals. The the content of polyphenols, free-radical scav- enging compounds, tended to decrease during the recovery period, but not during drought. Neither did the anti- oxidant activity of leaf tissue respond to water withholding. Germplasm that is able cope with novel environmental conditions seems to exist in Mexico. Future studies should survey yield responses to different drought intensities for various maizes from dry environments to help identify traits useful in future breeding programs
Maize core collection for increased grain quality
Get PDFFormation of the maize (Zea mays L) core collection for increased macronutrient content is presented. Among
3,443 populations from Maize Research Institute (MRI), Zemun Polje (ZP), a total of 352 accessions (around 10.2%) were chosen for the core collection. The criteria were increased protein, oil and/or starch content in the kernel of the accessions, as well as good combining ability (CA) that was tested with two Lancaster and one each BSSS and Iodent testers. Average values for protein, oil and starch content for the whole collection were 11.5%, 4.2% and 68.9%, respectively. On the other hand, averages for the core collection were 13.6% for proteins, 7.7% for oil and 74.1% for starch, and they were significantly higher than for the whole collection (
Revision of the Oriental Platyprosopus (Coleoptera Staphylinidae Platyprosopini). 255th Contribution to the knowledge of the Staphylinidae.
Get PDFIn this contribution, thirteen species previously known of Platyprosopus from the Oriental Region are redescribed and illustrated and the following new species are described: P. bengalensis sp. n., P. fulvaster sp. n., P. punctatissimus sp. n., P. laosianus sp. n., P. indawgyianus sp. n., P. meghalayaensis sp. n., P. ruficollis sp. n., P. himalayaensis sp. n., P. myanmarensis sp. n., P. birmanus sp. n. Megaprosopoda Strand is considered synonym of Platyprosopus Motschulsky. Neotype for P. biseriatus Epp. is designated. P. laevicollis Kr. is species revalidated. Lectotype and sometimes paralectotypes are designated for the following species: P. fraternus Bh., P. tongyai Bh., P. elatus Fvl., P. fuliginosus Er., P. tamulus Er., P. laevicollis Kr., P. bilineatus Fvl., P. parallelus Bh., P. fulvicollis Mot., P. socius Bh., P. indicus Mot., and P. consularis Fvl
A preliminary study for determination of the possibility of simultaneous selection for oil content and grain yield in maize
Get PDFWe investigated the genetic potential of six maize families for simultaneous selection of oil content and grain yield. Six generations of six families were generated in 2011 and 2012. These genotypes were tested in a field experi- ment, conducted in Dardanos Research and Application Center, Çanakkale, Turkey, in 2013. Data were collected on oil content and grain yield per plant and then analyzed by using Generation Mean Analysis method to determine the appropriate families for simultanous selection studies. We also calculated genetic effect estimations for these traits in the investigated genotypes.
Results showed that there were significant differences among the families and generations for oil content and grain yield. The variation in oil content in the families was mainly controlled by additive gene actions. Simultaneous selection did not seem feasible in the tested families, though there was a good chance for considerable enhance- ment in some genotypes if the investigated traits were taken into account singlehandedly. Three families (A680x- IHO, IHOxB73 and IHOxHYA) showed potential for selection to enhance oil content, while two others (IHOxMo17 and Mo17xIHO) were promising for grain yield. Estimated genetic gains were in the range of 0.4% to 4.1% per cycle for oil content, and 17.7 g to 60.7 g per cycle for grain yield
Drought responsive genes and their functional terms identified by GS FLX Pyro sequencing in maize
Get PDFDrought stress is a major challenge for the production of maize (Zea mays L), leading to reduced growth of aerial parts and, to a large extent, reproductive stages of development. We applied the 454 GS FLX titanium platform to identify drought differentially regulated genes in the maize vegetative and reproductive tissues. A total of 2,199 genes of which 1,284 in reproductive and 915 in vegetative tissues were identified by the platform. Quantitative RT-PCR of differentially expressed genes was carried out to confirm their expression. The results showed that the transcripts were correctly assembled and represented actively expressed genes, which genes were further subjected to gene ontology analysis for biological processes, molecular function and cell component functional terms. Significantly enriched terms indicates that catabolism of proteins and maintenance of cellular homeostasis processes were significantly enriched in the vegetative tissues, while on the other hand carbohydrate metabolism was enriched in the reproductive tissues. Photosynthesis, and energy metabolism as well as protein biosynthesis were highly repressed in both tissues. These add to the concept that drought stress target photosynthesis and causes a transition of metabolism from protein synthesis by repressing amino acid biosynthesis and translation to degradation by inducing the ubiquitin-proteasome pathway. Identified genes are potential candidates for maize improvement through transgenic and mutagenic approaches
Biological studies on Tomicus destruens (Wollaston) (Coleoptera Curculionidae Scolytinae): phenology, voltinism and sister broods.
Get PDFBiology and behaviour of Tomicus destruens were investigated in Sardinian pine forest in order to define the seasonal pattern of trunk attacks by breeding adults, the number of annual generations, and the number of sister broods produced per female. The counting of maternal galleries made each month in trap trees shows that T. destruens colonizes the pine trunk in all the months between October and May with the highest infestation intensity in autumn followed by decreasing values. Female laid ca. 80 to 95 eggs per gallery in October-November and ca. 70 in the following months. Although the bark beetle’s reproductive activity extended for a period of 7-8 months, the flight of new adults was concentrated in a much shorter time period between May and June, when ca. 95% of the emergences occurred. The experiments have ruled out the possibility of a second annual generation. Even the earliest emerging adults, originating from eggs laid in October, were unable to mature their gonads and oviposit before the summer stasis. Tomicus destruens females can make up to four sister broods and lay a total of ca. 170 eggs throughout their life, without regeneration feeding in the shoots. The new knowledge provides information useful to calibrate well-timed interventions to control this dangerous pest by means of the trap tree technique
Assessing the bibliometric productivity of forest scientists in Italy
Get PDFSince 2010, the Italian Ministry of University and Research issued new evaluation protocols to select candidates for University professorships and assess the bibliometric productivity of Universities and Research Institutes based on bibliometric indicators, i.e. scientific paper and citation numbers and the h-index. Under this framework, the objective of this study was to quantify the bibliometric productivity of the Italian forest research community during the 2002-2012 period. We examined the following productivity parameters: (i) the bibliometric productivity under the Forestry subject category at the global level; (ii) compared the aggregated bibliometric productivity of Italian forest scientists with scientists from other countries; (iii) analyzed publication and citation temporal trends of Italian forest scientists and their international collaborations; and (iv) characterized productivity distribution among Italian forest scientists at different career levels. Results indicated the following: (i) the UK is the most efficient country based on the ratio between Gross Domestic Spending (GDS) on Research and Development (R&D) and bibliometric productivity under the Forestry subject category, followed by Italy; (ii) Italian forest scientist productivity exhibited a significant positive time trend, but was characterized by high inequality across authors; (iii) one-half of the Italian forest scientist publications were written in collaboration with foreign scientists; (iv) a strong relationship exists between bibliometric indicators calculated by WOS and SCOPUS, suggesting these two databases have the same potential to evaluate the forestry research community; and (v) self-citations did not significantly affect the rank of Italian forest scientists