41 research outputs found
Biomass production of Populus nigra L. clones grown in short rotation coppice systems in three different environments over four rotations
Rabies and canine distemper virus epidemics in the red fox population of Northern Italy (2006–2010)
Since 2006 the red fox (Vulpes vulpes) population in north-eastern Italy has experienced an epidemic of canine distemper virus (CDV). Additionally, in 2008, after a thirteen-year absence from Italy, fox rabies was re-introduced in the Udine province at the national border with Slovenia. Disease intervention strategies are being developed and implemented to control rabies in this area and minimise risk to human health. Here we present empirical data and the epidemiological picture relating to these epidemics in the period 2006-2010. Of important significance for epidemiological studies of wild animals, basic mathematical models are developed to exploit information collected from the surveillance program on dead and/or living animals in order to assess the incidence of infection. These models are also used to estimate the rate of transmission of both diseases and the rate of vaccination, while correcting for a bias in early collection of CDV samples. We found that the rate of rabies transmission was roughly twice that of CDV, with an estimated effective contact between infected and susceptible fox leading to a new infection occurring once every 3 days for rabies, and once a week for CDV. We also inferred that during the early stage of the CDV epidemic, a bias in the monitoring protocol resulted in a positive sample being almost 10 times more likely to be collected than a negative sample. We estimated the rate of intake of oral vaccine at 0.006 per day, allowing us to estimate that roughly 68% of the foxes would be immunised. This was confirmed by field observations. Finally we discuss the implications for the eco-epidemiological dynamics of both epidemics in relation to control measures
Resposta in vitro e suscetibilidade ao Agrobacterium de duas cultivares de Stylosanthes guianensis
Variation in resistance to the rust fungus Melampsora larici-populina Kleb. in Populus nigra L. in the Czech Republic
Differences in Populus nigra L. clone resistance to the rust fungus Melampsora larici-populina Kleb. (MLP) were studied in field trials where infected trees were compared with fungicide-protected trees. MLP rust infections were assessed using a 6-point scale. Four parameters of poplar growth were also measured to gauge host response to infection: shoot thickness, shoot number at the end of the growing season, individual plant dry weight, and dry matter yield per unit area. Five of eight known pathogen virulence types were detected. Cumulative growth in shoot thickness in sprayed and unsprayed plots was similar in clones with high rust pathogen resistance, but significantly different in clones with low resistance. Clones with low resistance also exhibited delayed growth initiation in the year following infection, an effect attributed to lower food storage accumulated during the previous year, reflected in a reduction in stem diameter. Based on stem thickness measurements, it was confirmed growth ceased at the end of August. Average rust severity symptoms ranged from 2.75 to 4.22 on the 6-point scale. The percentage reduction for the various growth parameters resulting from rust infection ranged as follows: individual plant dry weight 5-64%; dry matter yield 21-66%; shoot number 17-46%; and stem diameter 1-35%. Exclusive of stem diameter, these reductions correlated with severity in MLP rust infection. The one exception was tolerance to rust infection displayed by one of the clones. Clones with the lowest growth reductions were 97/152 and 97/157. Growth and yield parameter variation as a result MLP resistance difference was observed among tested P. nigra clones. This variation can be viewed as confirmation that resistance observed in this study and P. nigra clones is a suite of quantitative traits. These findings have important implications for MLP resistance breeding programs
Variation in resistance to the rust fungus Melampsora larici-populina Kleb. in Populus nigra L. in the Czech Republic
Wild populations as a source of germplasm for black poplar (Populus nigra L.) breeding programmes
Záchrana‚ soustřeďování‚ uchování a využití genofondu rostlin k tvorbě kulturní krajiny včetně ohrožených a devastovaných území ČR: Ochrana genofondu ohrožených taxonů rostlin v ČR - ochrana taxonů množením rostlin klasickými a in vitro metodami‚ konzervace a repatriace ohrožených taxonů‚ studium metod populační genetiky‚ ověření genetické biodiverzity metodou DNA polymorfizmu:Využití metod populační analýzy z aspektu aktivní ochrany ohrožených druhů‚ stanovení genetické diversity metodou DNA polymorfismu
Cílem projektu je zjištění genetické diverzity souboru jedinců topolu černého z oblastí Moravy a u jejich potomstev z kontrolovaného křížení metodou analýzy DNA (mikrosatelity), stanovení nejmenšího rozsahu populace černého, kdy ještě nedochází k úbytku genové výbavy. Výsledky mají být uplatněny při modelové výsadbě. Byly analyzovány dospělé stromy z přírody, potenciální rodiče semenáčků z přirozené obnovy, provedena analýza mikrosatelitů u potomstva z příbuzného křížení výběrových stromů a proběhlo měření potomstev z kontrolovaného křížení