Key message The investigation provides initial knowledge on the distribution and evolution of the high and low methyl salicylate-producing trait in the Betula genus. Mislabelled birch species could be identified and removed. Abstract The genus Betula is the largest group of ecologically and economically dominant perennial woody plants in subalpine forests. The taxonomy of Betula is complex due to an extensive history of hybridization and periodic introgression events among the species. Although almost all land plants including birches produce methyl salicylate (MeSA) as a signaling molecule and in response to stress (“low MeSA producer”), some birch species produce high amounts of MeSA in the leaves and bark (“high MeSA producer”). Unfortunately, the evolution of high levels of MeSA production in the genus Betula remains unclear. The salicylic acid-binding protein 2 (SABP2) and salicylic acid methyltransferase (SAMT) genes involved in MeSA biosynthesis were incorporated into this study to examine the interspecific relationship of high and low MeSA-producing birches. Additionally, eight chloroplast and three nuclear regions were included to evaluate their potential application in species determination. The analysis resulted in 25 and 61 nucleotide variations, respectively, which allowed for a visualization of the genetic architecture in the 18 Betula species investigated. The high MeSA-producing B. lenta, B. grossa, and B. alleghaniensis formed the basal clade in the phylogenetic analysis, thus revealing their ancestral status, and the network analysis postulates that the diploid B. lenta is one of the ancestors of the genus Betula. The results indicate that the ability to produce high levels of MeSA that were initially present in the genus has been lost several times during its evolution. Placing species of the subgenus Acuminata alongside the subgenus Betula, together with a fragrance analysis, questions their ability to produce high levels of MeSA.

Recently biogas production from agricultural sources has rapidly developed. Therefore the demands on biogas plants to optimise the efficiency of the anaerobic digestion (AD) process have grown immensely. At present there is no online-supervision tool available to monitor the AD process, but costly and time-consuming chemical analyses are necessary. The possibility to use near-infrared spectroscopy (NIRS) in order to track relevant process parameters like total volatile fatty acids (VFA), acetic acid and propionic acid was investigated in the present research project. A NIR-sensor was integrated into a full-scale 1 MW biogas plant and NIR-spectra of the fermenter contents were recorded semi-continuously for 500 days. Weekly samples were taken and analysed for the above mentioned parameters. Calibration models were calculated, capable of following these parameters: VFA (r(2)=0.94), acetic acid (r(2)=0.69), propionic acid (r(2)=0.89).

Estimating the content of free fatty acids in high-oleic sunflower seeds by near-infrared spectroscopyThe content of free fatty acids (FFA) in vegetable oils represents an important quality factor in oil crops. The objective of the investigation was to develop a near-infrared (NIR) calibration for estimating the FFA content in high-oleic sunflower seeds. A sample set of different varieties from the harvest of 2004 as well as of 2005 from two locations in Germany was used; additionally seeds from 2003 were stored under unsuitable conditions to obtain samples utilised for calibration with an extended FFA range. A direct titration method for FFA determination was developed and adjusted to the official AOCS method. The modified method is sufficiently reliable, much faster than the AOCS method and therefore suitable for use in the calibration of NIR spectrometers. The developed NIR spectroscopy (NIRS) calibration was calculated with a modified partial least square algorithm, standard normal variate and detrend scatter correction and the 2 nd derivative of the spectra of ground sunflower seeds. The standard error of prediction of the validated calibration was 0.20, and the multiple coefficient of determination (RSQ val ) reached 0.94. The obtained results demonstrated clearly the efficiency and how cost effective the NIRS method is for the estimation of FFA content in sunflower seeds.

Species of the perennial woody plant genus Betula dominate subalpine forests and play a significant role in preserving biological diversity. In addition to their conventional benefits, birches synthesize a wide range of secondary metabolites having pharmacological significance. Methyl salicylate (MeSA) is one of these naturally occurring compounds constitutively produced by different birch species. MeSA is therapeutically important in human medicine for muscle injuries and joint pain. However, MeSA is now mainly produced synthetically due to a lack of information relating to MeSA biosynthesis and regulation. In this study, we performed a comprehensive bioinformatics analysis of two candidate genes mediating MeSA biosynthesis, SALICYLIC ACID METHYLTRANSFERASE (SAMT) and SALICYLIC ACID-BINDING PROTEIN 2 (SABP2), of high (B. lenta, B. alleghaniensis, B. medwediewii, and B. grossa) and low (B. pendula, B. utilis, B. alnoides, and B. nana) MeSA-producing birch species. Phylogenetic analyses of SAMT and SABP2 genes and homologous genes from other plant species confirmed their evolutionary relationships. Multiple sequence alignments of the amino acid revealed the occurrence of important residues for substrate specificity in SAMT and SABP2. The analysis of cis elements in different birches indicated a functional multiplicity of SAMT and SABP2 and provided insights into the regulation of both genes. We successfully developed six prominent single nucleotide substitution markers that were validated with 38 additional birch individuals to differentiate high and low MeSA-producing birch species. Relative tissue-specific expression analysis of SAMT in leaf and bark tissue of two high and two low MeSA-synthesizing birches revealed a high expression in the bark of both high MeSA-synthesizing birches. In contrast, SABP2 expression in tissues revealed indifferent levels of expression between species belonging to the two groups. The comparative expression and bioinformatics analyses provided vital information that could be used to apply plant genetic engineering technology in the mass production of organic MeSA.

Reliable analytical methods are necessary in order to determine different quality parameters of sunflowers achenes and to realize their optimum utilization in food and non-food industries. For this aim, different near-infrared methods have been developed for ground and intact high-oleic sunflower achenes. These methods determine simultaneously the important quality parameters like oil and protein content and the composition of fatty acids. The methods are adequately exact and more time-and cost-saving than the conventional reference analysis.In addition to further optimization of the NIRS methods, transfer of the calibration-equations will be worked out. This will lead to a better utility for all those concerned with cultivation, marketing and breeding of sunflowers.