Drought induces opposite changes in the concentration of non-structural carbohydrates of two evergreen <Emphasis Type="Italic">Nothofagus</Emphasis> species of differential drought resistance

• Introduction   

One current explanation for worldwide drought-induced tree mortality states that reduced photosynthesis and continued respiration lead to carbon depletion and eventually to carbon starvation.     

Content and structure of Swedish animal welfare legislation and private standards for dairy cattle

In this study the animal welfare legislation and three private standards in Sweden, focusing on dairy cows, were analysed. The aim was to investigate to what extent these regulations consisted of resource-, management- or animal-based requirements, to analyse the content and discuss consequences. The results showed a higher proportion of management- and resource-based requirements than animal-based in all regulations. However, the borders between these categories were not as distinct as expected. The private standards put slightly more emphasis on the animal-based requirements and on animal welfare at herd level. It was primarily the organic standard that included higher animal welfare demands than the legislation. Due to vague wording and guideline statements it was not always clear if the welfare level achieved would be the same in practice although the requirements were similar. It will be necessary to clearly distinguish between requirements and measures to make the policy process more transparent.     

A heritable colour deviation in red table beets (Beta vulgaris var. Rubra L.) 2. Mode of inheritance

Euphytica - A study was made on the inheritance of an orange-yellow colour deviation in red table beets. This disorder proved to be governed by a number of genes, presumably partly acting in an...     

Detection of Erwinia herbicola pv. gypsophilae in gypsophila plants by PCR

Three PCR primer pairs, based on the cytokinins (etz) or IAA biosynthetic genes, were used for detecting Erwinia herbicola pv. gypsophilae in Gypsophila paniculata plants. The primers were specific to all gall-forming E. herbicola strains and distinguished them from saprophytic strains associated with gypsophila plants or from other gall-forming bacteria. In pure culture of the pathogen, less than one bacterial cell was detected with nested PCR using the etz primers - an increase of 100-fold in sensitivity as compared with single-round PCR. In the presence of plant extract a reduction of tenfold in sensitivity was observed by nested PCR. When cells were grown on a semi-selective medium prior to PCR (Bio-PCR), five cells from pure culture of the pathogen were detected. The bacteria could be detected by nested-PCR or Bio-PCR in symptomless gypsophila cuttings after 7 days. The Bio-PCR procedure described in this study can be used to establish disease-free nuclear stock of mother plants of gypsophila.     

Differences in soil organic matter, extractable nutrients, and acidity in European beech (Fagus sylvatica L.) forest soils related to the presence of ground flora

Differences in soil organic matter (SOM) content, soil acidity, and soil exchangeable nutrients (NH₄–N, NO₃–N, Ca, K, Na, Mg) related to the presence of ground flora were studied. The study was carried out for a growing season in two different Fagus sylvatica L. forests in southern Sweden, and the differences in soil characteristics below naturally occurring patches of Deschampsia flexuosa (L.) Trin. or Anemone nemorosa L. were compared with those with no ground flora. Patches of D. flexuosa led to higher soil pH, but lower SOM, water content, base saturation, and NH₄–N concentration compared with adjacent zones without D. flexuosa. The lower SOM content suggested an increased rate of decomposition which caused soil pH to increase because of release of basic cations. In the presence of A. nemorosa, pH was higher and the exchangeable acidity lower than for patches without the herb. In early spring, when A. nemorosa emerged and flowered, the NH₄–N concentration was somewhat lower in the presence of the herb than when it was absent. For the evergreen grass D. flexuosa NH₄–N concentrations were lower in patches with the grass later in the summer season (July). This work indicates the presence of spatial and temporal differences in nutrient circulation and decomposition on the small ground flora scale, which should be considered when studying nutrient and carbon cycles of temperate forests.     

Solid shelter tubes alleviate summer stresses during outplanting in drought-tolerant species of Mediterranean forests

New Forests - The effect of shelter tubes on plant performance has been widely studied. Although, the role of shelter tubes in alleviating the effects of drought and high-irradiance stresses during...     

Breeding research on rose pigments. II. Combining ability analyses of variance of four flavonoids in F1 populations

Summary 18 Hybrid Tea-rose varieties were crossed and selfed in an incomplete diallel. In F₁ seedlings the relative contents of the flavonoids: pelargonidin, cyanidin, kaempferol and quercetin, were determined by means of paper chromatography. Inheritance of each pigment was mainly controlled by additive gene action. Combining ability analyses of variance of these pigments showed highly significant differences between GCA's of the varieties. The pigment content of parent varieties can be a useful basis for breeding.     

Functions of time for growth characters,their evaluation and approximation to examine differences between genotypes

Summary As a follow up to a previous paper on growth curves (Keuls & Garretsen, 1982) a procedure is described to derive functions of time for growth characters from elementary growth curves which are suited for statistical analysis.For each plot from the parameters , , of the second degree growth curves of type + (t–t) + (t–t)², corresponding functions of time (of harvest) are obtained for the derived growth characters: relative growth rate (of dry weight per plant), net assimilation rate, leaf area ratio, specific leaf area, leaf weight ratio. The elementary growth curves concern ln W, ln LA and ln LW, where W = dry weight per plant, LA = leaf area per plant, LW = leaf dry weight per plant.Only relative growth rate is a simple linear expression in t, i.e., + 2(t–t), where t represents average harvest time.The functions for the four other growth characters are approximated by quadratic functions in t, such that for each plot a curve is characterized by a triple of parameters f(t), f(t), % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaKabGfaammaalaaaba% Gaaiymaaqaaiaackdaaaaaaa!3946!\[\frac{1}{2}\]f(t), representing respectively mean, slope and curvature for that plot at time t The approximation of the function of time is given by f(t) + (t–t)f(t) + % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaKabGfaammaalaaaba% Gaaiymaaqaaiaackdaaaaaaa!3946!\[\frac{1}{2}\](t–t)²f(t).These sets of parameters per plot: (, , ) for ln W(t) etc.; (, 2, 0) for RGR(t) or (f(t), f(t), % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaKabGfaammaalaaaba% Gaaiymaaqaaiaackdaaaaaaa!3946!\[\frac{1}{2}\]f(t)) for the four other growth characters can be analysed by the MANOVA-procedure for 3 parameters as exemplified by Keuls & Garretsen (1982).