CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
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Identification of significant loci for drought resistance and root traits at seedling stage with a set of maize introgression lines
Get PDFGenetic dissection of the genetic basis of drought resistance is important for crop improvement. In this study, significant loci for drought resistance related traits at seedling stage were identified with a set of maize introgression lines under two environments. Two drought resistance indicators, leaf-drying degree under medium drought stress (LDM) and severe drought stress (LDS), and three root traits, root dry weight under drought stress (RWS), root length under drought stress (RLS), and root number under drought stress (RNS) were investigated. A total of 31 and 25 significant loci for LDM and LDS were identified, respectively, and 20 of them were commonly detected under both environments. For the three root traits, 41 significant loci were detected with 20 loci identified under both environments. Of the 97 significant loci, only 19 loci related to both leaf-drying degree and root traits under stress simultaneously, suggesting that these root traits had limited contribution to drought resistance at seedling stage. The significant loci detected in this study would be useful in molecular breeding for drought resistance in maize
Early impact of alternative thinning approaches on structure diversity and complexity at stand level in two beech forests in Italy
Get PDFStand structure, tree density as well as tree spatial pattern define natural dynamics and competition process. They are therefore parameters used to define any silvicultural management type. This work aims to report first data resulting from a silvicultural experiment in beech forests. The objective of the trial is testing the structure manipulation in terms of diversity and the reduction of inter-tree competition of different thinning approaches. Alternative thinning methods have been applied in two independent experimental sites located in the pre-Alps and Southern Apennines, in Italy. Specific goals were to: (i) verify the impact early after thinning implementation on forest structure through a set of diversity and competition metrics resulting from a literature review; (ii) the sensitivity of tested indexes to effectively detect thinning manipulation. Main result show the low sensitivity of stand structure indexes and the ability of competition metrics to detect thinning outcome
Status and changes of ground vegetation at the CONECOFOR plots, 1999 - 2005
Get PDFThe vegetation dataset (1999-2005) of the CONECOFOR network is analyzed in the paper, to produce a present-day status and evaluation of changes in a sub-set of Permanent Monitoring Plots (PMPs). Descriptors such as mean number of species (community and population scale), diversity indices and species turnover were selected. Each PMP was investigated to evaluate: (i) type and direction of variations; (ii) significant changes of species indicator values. At the community level, significant variations in richness occurred in sites affected by recent anthropic or natural disturbances. In few PMPs directional changes can be observed; in most of cases a typical fluctuation pattern (more or less regular) was detected. The use of a priori reference standard (RS) supported the interpretation of changes. At finer scale (population level), annual richness variations are frequent but of minor importance. Higher values of species turnover occurred in communities under intense dynamic processes, interested by disturbance or influenced by neighboring communities. The abundance of nitrophilous species was consistent in beech forests, while the contribution of acidophilous species was not important. Moreover, our results suggest that: (a) the data collected at the community level seem more sensitive to describe important changes at the forest stand level; (b) a strong relationship is present between plant diversity and the forest dynamical state. The inherent non-linear dynamics of forest regeneration processes emphasizes the needs of long-term datasets for detecting the plant diversity responses to environmental changes
Ecological transformations in the forest landscape unit at one alpine spruce (Picea abies K.) CONECOFOR plot, 1998-2004
Get PDFThe landscape unit (LU) of the Lavazé Pass (Trentino-AltoAdige) is mainly formed (75.3%) by a forest cover dominated by Picea abies. In the period 1998-2004 the LU changed the composition of its forest cover because of the increasing of the ski rides (+2.9%) and the naturally destroyed patches (+3.1%). These quite small transformations did not change the geo-botanical structure of the LU, while carried altered ecological consequences. The diagnostic index of the LU, based on a set of 10 landscape ecological parameters, diminished in only 6 years from 0.75 to 0.60. Consequently, in absence of re-balancing interventions, the landscape characters of the LU are changing from semi-natural to managed ones, thus affecting the selected plot too
An eighty years long history
Get PDFAn eighty years long historyAnnals of Silvicultural Research (ASR) take over and are the on line follow-up of the former Annali. The Annali are a body of 36 volumes issued since 1970 from the Experimental Institute of Silviculture, then Forestry Research Centre of the Consiglio per la Ricerca e la sperimentazione in Agricoltura (CRA). They originate from the series of Papers of the same Institution (n. 15-18, 1968-69) and formerly of the Royal Station of Silviculture in Firenze (n. 1-14, 1932-67). The history of Annals dates therefore back to 80 years ago and covers quite completely the activity of our Institution since its early establishment in Firenze in 1922.Institutional duty of the Annali was the scientific dissemination of research trials’ outcomes and findings to the manifold stakeholders’ levels and was aimed at an effective transfer of knowledge and innovation in the practice of forestry. The Annali housed original research papers produced inside and in cooperation with researchers outside on the subject-matters of forest ecology, silviculture of semi-natural forests and forest plantations for environmental restoration and wood/ non-wood productions, tree farming and agro-forestry, forest mensuration and stand dynamics, dendro-ecology, conservation and valorization of genetic resources and levels and types of biodiversity, protection and provision of forest ecosystems services, maintenance of their multifunctional role, up to the more recent theme of the adaptive management framed within the environmental change in progress and related issues of forests’ mitigation & carbon sequestration/ stocking ability.A review of research topics and thematic volumes handled throughout the eighty years highlights the attention paid towards the national emerging subject-matters, since the Experiments on the introduction of exotic species in Italy by Pavari and De Philippis (1941), to its conclusive follow-up forty years later Role of exotic species in the Italian silviculture (1981-82), up to the special issues dealing with national and European projects joined by the Institution as coordinator or partner. Among these, it is worth reminding volumes on Tree farming experiments with valuable hardwood broadleaves (1994-95), Management of coppice forests in the Med. area (1996), and the four volumes on the activity of Italian teams involved in the Intensive monitoring of forest ecosystems within ICP-Forests programme (1999-2006). Up to 1993, submitted papers underwent a peer-review at care of R. Morandini, director and member of many editorial boards in Italy and abroad. Since 1994, the referees’ committee was officially declared and issued. It was renewed per volume according to contents and expertise required. Scientists of other networks in Italy and foreign countries took usually part in the referees’ committee. The Editorial staff, together with Guest editors in case of special issues, took care of the revision process. The Annali were issued in 1500 copies and distributed over 45 countries in Europe and outside Europe. Their diffusion allowed the exchange with about 100 foreign Journals and largely contributed to update the collection of periodicals at our library.The editorial format was renewed in 1996 (vol. 27) and since 1999 (vol. 30) texts are available also in digital format. Full texts of special issues dealing with international research activity were published in English.The Annali archive URL is http://ojs-cra.cilea.it/index.php/asr/issue/archive Annals of Silvicultural Research (ASR) ASR are now part of the CRA Journals published by the Consiglio per la Ricerca e la sperimentazione in Agricoltura. The newly born Annals are a double blind peer-reviewed open access journal aimed at maintaining an updated form of scientifically and technically sound dissemination of main research and experimental findings. Its diffusion is addressed to the suite of stakeholders - scientists, technicians, managers, Forest Services, Governmental and Non- Governmental Organizations concerned with forest environment, silviculture and related issues. Preferred language of submission is English, but Italian is also allowed. ASR feature original research papers, review papers, concept notes and technical notes to meet all different challenges in research and innovation launched by the scientific community in the field of forestry.Contributions are open to research scientists from any Research Institutions and Networks and to independent researchers. Also the Editorial Team has been renewed including international experts to cover all topics considered by the journal.The subject-matters of ASR are the theory and the practice of silvicultural systems and related forestry issues. Distinctively, the journal deals with research experiences concerning the: (a) theoretical development and check in the practice of innovative criteria and methods of cultivation of semi-natural forests and forest plantations; (b) conservation of forest biodiversity and environmental protection; (c) bio-ecological functioning and monitoring of forest ecosystems under-cultivation and in post-cultivation phase; (d) maintenance and improvement of forest genetic resources; (e) forest management, inventory and geomatics to support silvicultural systems’ application; (f) forest tree farming and integrated agro-forestry systems; (g) silvicultural prevention of forest fires and post-fire management.The Annals of Silvicultural Research URL is http://ojs-cra.cilea.it/index.php/asr/index I do hope the journal will be able to gain more and more consideration by the forest scientific community and, meanwhile, I would like to thank all the Executive Editors as well as the Editorial assistants for the intense work at the start-up of the new journal. I want to thank the Editorial Board too for contributing to improve hereafter the scientific quality of issued papers. A particular acknowledgement is due to Paola Corsaro and her team as Scientific Dissemination Service at CRA. Finally, a special thank to Piermaria Corona, Director of the Forest Research Centre for the incentive to start this experience, for the active and proficient role, for the support during the start up of the journal.
Empirical modelling of chestnut coppice yield for Cimini and Vicani mountains (Central Italy)
Get PDFoai:journals.crea.ugov.it:article/749The prescription of stand rotation according to site conditions and economic targets requires yield information that expresses stand productivity under different site-classes. This is particularly relevant for the optimal management of chestnut coppices allowing the production of timber assortments sized differently. This paper reports a new yield model built for chestnut coppices of the Cimini and Vicani mountains (Central Italy), according to three site index classes. The model focuses on the development of stands after an intense thinning carried out at the ages of 13-14 years. The model is compared with two previous yield tables built for chestnut coppice forests living in the same area and including one site index class only. The study stresses the high productivity of chestnut coppices growing on the volcanic soils of Cimini and Vicani mountains and shows how the growth course following intense thinning allows to get stems with large mean volume at the end of rotation. In the light of the most recent studies on the causes of ring shake, i.e. the most relevant defect of chestnut wood, the negative consequences on timber quality originating from the current thinning regime are also outlined.The prescription of stand rotation according to site conditions and economic targets requires yield information that expresses stand productive potential under different site classes. This is particularly relevant for the optimal management of chestnut coppices whose wood has qualities that allow the production of timber assortments of various sizes. This article reports a new yield model built for the chestnut coppices of the Cimini and Vicani mountains (Central Italy), according to three site index classes. The model focuses on the development of the stands after intense thinning carried out between 13 and 15 years. The model is compared with two previous yield tables for coppices of the same area comprising only one class of fertility. The study confirms the high productivity of chestnut coppices growing on the volcanic soils of Cimini and Vicani mountains and shows how the low stand density by intense thinning allows to obtain stems with large mean volume. In the light of the most recent studies on the causes of ring shake, the most relevant defect of chestnut wood, the negative consequences on the quality of the timber brought about by the current thinning regime are also outlined
Structural and ecological changes in holm oak coppices 25 years after their conversion into high forest
No full textHolm oak (Quercus ilex L.) is one of the most diffuse and economically important forest species in Sardinia, where it holds about 40% of holm oak cover in Italy. The forest type has also acquired a high ecological, recreational and landscape value over the last decades. Most of holm oak stands originated from overgrown coppice forests partly undergoing conversion into high forest. This study was set up in 1994 to analyse, as a function of site-index, the effects of conversion thinning on productivity, biodiversity, structural dynamics and canopy characteristics in an holm oak forest located in southern Sardinia. Two experimental permanent plots, differing in site index, stand structure and tree density, were established. The surveys were carried out in 1994-95 and 2010-11. The analysis included growth pattern, dynamics of stand structure and estimation of forest canopy attributes as leaf area index and canopy transmittance. Results pointed out the simplified stand structure, the poor biodiversity, the low LAI and high transmittance values 9 years after thinning implementation. These characteristics were more pronounced in the less productive area, characterised by substantial canopy gaps. 25 years after thinning implementation, both stands showed significant increase in the number of trees, strengthening of the clustered structure and high canopy recovery. Conversely, no significant changes in biodiversity and vertical structure were observed. Overall results contributed to a positive evaluation of the conversion practice based on periodical thinnings, even if the excessive reduction of tree density, mainly in the lower site-index area, did not allow yet the fully achievement of canopy recover
Breeding grasses for capacity to biofuel production or silage feeding value: an updated list of genes involved in maize secondary cell wall biosynthesis and assembly
Get PDFIn the near future, maize, sorghum, or switchgrass stovers and cereal straws will be a significant source of carbohydrates for sustainable biofuel production, in addition to the current use of grass silage in cattle feeding. However, cell wall properties, including the enzymatic degradability of structural polysaccharides in industrial fermenters or animal rumen, is greatly influenced by the embedding of cell wall carbohydrates in lignin matrix, and the linkages between lignins, p-hydroxycinnamic acids, and arabinoxylans. Breeding for higher and cheaper biofuel or silage production will thus be based on the discovery of genetic traits involved in each cell wall component biosynthesis and deposition in each lignified tissue. Due to its considerable genetic and genomic backgrounds, maize is the relevant model species for identifying traits underlying cell wall degradability variations in grasses. Maize genes involved or putatively involved in the biosynthesis of cell wall phenolic compounds, cell wall carbohydrates and regulation factors were therefore searched for using data available in grass, Arabidopsis, and woody species (mostly poplar and eucalyptus). All maize ortholog genes were searched for using protein sequences and a “blastp” strategy against data available in the www.maizesequence.org database. Genes were also mapped in silico considering their physical position in the same database. Finally, 409 candidate genes putatively involved in secondary cell wall biosynthesis and assembly were shown in the maize genome, out of which 130 were related to phenolic compound biosynthesis, 81 were related to cell wall carbohydrate biosynthesis, and 198 were involved in more or less known regulation mechanisms. Most probable candidate genes involved in regulation and assembly of secondary cell wall belonged to the MYB (45 genes) and NAC (38 genes) families, but also included zinc finger and HDZipIII encoding genes. While genes involved in ferulic acid cross-linkages with other cell wall components were little known, several families putatively involved in (arabino)-xylan chain biosynthesis and in feruloyl transfer were shown, including especially arabinosyl-CoA-acyltransferases, feruloyl-AX b-1,2-xylosyl transferases, and xylan-O-3-arabinosyl transferases. This candidate gene list, which focused on genes and orthologs known to be involved in cell wall component biosynthesis and regulation, cannot be considered as exhaustive. Other genes, whose role in cell wall lignification and deposition have not yet been defined, should very likely be added to the list of candidates required for secondary cell wall assembly. Genes encoding proteins of still unknown function should also be added to the list, as several of the latter are probably involved in lignified tissue biosynthesis and deposition
Performance of tropical maize hybrids under conditions of low and optimum levels of nitrogen fertilizer application – grain yield, biomass production and nitrogen accumulation
Get PDFNitrogen (N) is the most limiting mineral nutrient in the soils of the major maize producing areas of West and Central Africa. Low soil N and sub-optimal application of N fertilizers lead to N deficiency and poor grain yield (GY) in maize. Maize varieties with improved grain yield under low soil N and increased performance under optimal N availability could be beneficial to low input agriculture. This study evaluated the performance of a selection of experimental and commercial hybrids under suboptimal and optimal N fertilizer applications. Significant differences were observed among the hybrids, as well as significant interactions between hybrid and N level for GY and other measured attributes, with the severity of variation increasing as the level of N decreases. Mean GY reductions across the years was 76.5% at no-N and 35.4% at low-N. Depending on N treatment, GY varied from 0.48 to 4.42 Mg ha-1, grain N content from 0.17 to 1.26 g plant-1, total N content at harvest from 0.33 to 2.00 g plant-1, above ground biomass at silking from 30.6 to 91.2 g plant-1 and at maturity from 39.9 to 191.1 g plant-1. Number of kernels was the GY component most severely reduced by N stress and had significant (p = 0.001) positive correlation with GY at all N levels. Six hybrids (4001/4008, KU1409/4008, KU1409/9613, 4008/1808, 4058/Fun 47-4, and 1824/9432) which showed consistent above average grain yields under no-N, low-N, high-N and across N levels were found and their use could further be investigated
Mapping of QTL affecting resistance against sorghum downy mildew (Peronosclerospora sorghi) in maize (Zea mays L)
Get PDFSorghum downy mildew (SDM) is one of the most destructive diseases of maize (Zea mays L) in South-East Asia. Understanding the genetic basis of downy mildew resistance (DMR) could increase the efficiency of breeding for disease resistant germplasm. The objectives of this study were to determine the number, genomic positions and genetic effects of quantitative trait loci (QTL) conferring resistance to SDM. The study included 251 F2:3 families derived from a cross between the two inbreds, Nei9008 (Thailand) and CML289 (CIMMYT), resistant and susceptible, respectively. Individuals in the population were genotyped for simple sequence repeat (SSR) and phenotypic resistance data were evaluated as percentage disease incidence in replicated field trials at three environments by Triple Lattice design. Heritability across environments was 94.3%. Traits were analyzed within and across environment using composite interval mapping. Nine QTLs were identified for resistance to SDM, one QTL each on chromosome 2, 3, 4, and 6, three QTLs on chromosome 5, and two QTLs on chromosome 9. Just one QTL on chromosome bin 5.07 came from the susceptible parent, all others from the resistant parent, Nei9008. The QTLs in chromosome bins 2.09 at umc1736, 5.03 at bnlg1902, and 6.01 at bnlg1867 had major effects and were consistent over all environments. A common map shows intriguing collocations of SDM QTLs with those for other disease and insect resistance QTLs from literature. As several consistent QTLs for downy mildew resistance are available now, an avenue is open for pyramiding multiple genes by marker assisted selection (MAS) that may control different mechanisms for resistance