Identification of betalains from petioles of differently colored Swiss chard (Beta vulgaris L. ssp. cicla [L.] Alef. Cv. Bright Lights) by high-performance liquid chromatography-electrospray ionization mass spectrometry

The betalain pattern of differently colored Swiss chard (Beta vulgaris L. ssp. cicla [L.] Alef. cv. Bright Lights) was investigated for the first time. Nineteen betaxanthins and nine betacyanins were identified by RP-HPLC and positive ion electrospray mass spectrometry, co-injection experiments with semisynthetic reference compounds, and standards derived from authentic plant material, respectively. Histamine-betaxanthin and alanine-betaxanthin were found to be novel betaxanthins, which to the best of our knowledge have not been reported as natural compounds until now. Furthermore, tyramine-betaxanthin (miraxanthin III) and 3-methoxytyramine-betaxanthin, which to date were known only from families other than the Chenopodiaceae, were detected for the first time in colored Swiss chard. The betacyanin pattern of purple petioles was composed of betanin, isobetanin, betanidin, and isobetanidin. Although phyllocactin was present in only trace amounts, further acylated structures such as betanidin-monoferuloyl-5-O-beta-diglucoside and lampranthin II, accompanied by their corresponding C(15)-epimers, were identified. In addition, quantification of betalains and CIE LCh degrees measurements were performed with the colored extracts to correlate the visual appearance with the respective pigment patterns. Besides the novel phytochemical findings, the present study is useful for the evaluation of betalainic Swiss chard as a potential coloring foodstuff.     

Vitamin A excreted in the urine of canines is associated with a Tamm-Horsfall like protein

Under physiological conditions canines transport vitamin A in blood plasma primarily as retinyl esters bound to lipoproteins and excrete substantial amounts of vitamin A as retinol and retinyl esters with urine. In the aqueous environment of urine, the hydrophobic vitamin A has to be associated with a protein. This vitamin A-protein complex was purified to homogeneity, prepared by preparative ultracentrifugation (density 1.21 g/mL), native polyacrylamide gel electrophoresis (PAGE) and size exclusion chromatography. The vitamin A-protein complex has a high molecular mass of > 5,000 kDa under native conditions. SDS PAGE under reduced conditions revealed a single band with a molecular mass of about 100 kDa for the protein moiety. Peptides obtained after limited proteolysis with trypsin from the 100 kDa protein were characterised by MALDI-TOF mass spectrometry and showed amino acid sequence homology to the human Tamm-Horsfall Protein (THP). This was further confirmed by a positive immunoreaction of the isolated protein with crossreacting human THP antibodies. The localisation of THP in dog kidneys was determined by using immunohistology. The reaction was strong along the entire thick ascending limb ofthe Henle loop and distal convoluted tubule. Our data point to the possibility that THP functions as a novel carrier for vitamin A in the urine of canines.     

The phosphorus status of German cropland—An inventory of top‐ and subsoils

Background : In search for more sustainable crop production, the subsoil has recently come into focus as considerable reservoir of nutrients and water. Aims : Dimensions of subsoil phosphorus (P) reserves are yet largely unknown but crucial for identifying regions suitable to include subsoil into sustainable management strategies. Methods : We analyzed stocks of total and plant‐available (calcium acetate lactate‐extractable) P in 96 representative soil profiles of German arable land down to 1 m depth. Results : We found that the German arable soils stored, on average, 8 t ha^?1 of total P, of which nearly 500 kg ha^?1 were readily plant‐available. Notably, one third of plant‐available P was located below the plow layer and one fifth even at depths below 0.5 m. The depth gradients of plant‐available P stocks were affected more by major reference soil group than by texture. Generally, Chernozem but also Anthrosol, Gleysol and Fluvisol exhibited the largest P stocks in German cropland. The contribution of plant‐available P to total P stocks was larger in sandy and extremely acidic (pH < 4.5) soils compared with more fine‐grained and slightly acidic to alkaline soils, possibly because fertilization compensated for overall lower total P stocks at these sites. Generally, the more P was stored in topsoils, the more P was stored also in subsoils. Conclusions : A hypothetical crop utilization of 10% from plant‐available P stocks and 0.1% from total P stocks from shallow subsoil could compensate for P fertilization by ca. 8 kg ha^?1, but the rate of plant‐available P replenishment in subsoil likely remains the crucial factor for the role of subsoil P stocks in crop nutrition. Generally, the large P reserves found in subsoil could act as an ‘insurance' system for crops.     

Modelling the impact of climate change on woody plant population dynamics in South African savanna

Background

In Southern Africa savannas climate change has been proposed to alter rainfall, the most important environmental driver for woody plants. Woody plants are a major component of savanna vegetation determining rangeland condition and biodiversity. In this study we use a spatially explicit, stochastic computer model to assess the impact of climate change on the population dynamics of Grewia flava, a common, fleshy-fruited shrub species in the southern Kalahari. Understanding the population dynamics of Grewia flava is a crucial task, because it is widely involved in the shrub/bush encroachment process, a major concern for rangeland management due to its adverse effect on livestock carrying capacity and biodiversity.

Results

For our study we consider four climate change scenarios that have been proposed for the southern Kalahari for the coming decades: (1) an increase in annual precipitation by 30–40%, (2) a decrease by 5–15%, (3) an increase in variation of extreme rainfall years by 10–20%, (4) and increase in temporal auto-correlation, i.e. increasing length and variation of periodic rainfall oscillations related to El Niño/La Niña phenomena. We evaluate the slope z of the time-shrub density relationship to quantify the population trend. For each climate change scenario we then compared the departure of z from typical stable population dynamics under current climatic conditions. Based on the simulation experiments we observed a positive population trend for scenario (1) and a negative trend for scenario (2). In terms of the projected rates of precipitation change for scenario (3) and (4) population dynamics were found to be relatively stable. However, for a larger increase in inter-annual variation or in temporal auto-correlation of rainfall population trends were negative, because favorable rainfall years had a limited positive impact due to the limited shrub carrying capacity.

Conclusions

We conclude that a possible increase in precipitation will strongly facilitate shrub encroachment threatening savanna rangeland conditions and regional biodiversity. Furthermore, the negative effects found for positive auto-correlated rainfall support current ecological theory stating that periodically fluctuating environments can reduce population viability because species suffer disproportionately from poor environmental conditions.     

Early detection of Verticillium wilt resistance in a potato breeding program

Nine potato clones/cultivars selected for varying degrees of Verticillium wilt (VW) resistance based on degree of vascular colonization, were intercrossed and outcrossed to 13 uncharacterized clones. Based on growth characteristics of 3,535 seedling transplants and an assay quantifyingV. dahliae in potato vascular tissue, 404 clones were selected for further tests. The average number ofVerticillium dahliae colony forming units (CFU) expressed as Log₁₀(CFU + l)/0.1 ml of plant sap for the 404 clones was 2.3, and 1.3 and 3.7 for resistant Reddale and susceptible Kennebec checks, respectively. Thirty-five clones (8.66%) had CFU values equal to or less than Reddale suggesting that VW resistance is a readily transmitted trait.     

A possible genetic source for chipping potatoes from 40 F storage

An interspecific hybrid ofS. phureja x USW1, a haploid of Katahdin, produced acceptable potato chips when processed directly from 40 F (4.5 C) storage during 3 years of testing. It was crossed with 11 interspecific hybrids. Tubers from these progenies were stored for 5 weeks at 40 F and then chipped immediately for 55 seconds in vegetable oil maintained at 375 F (190 C). Of 645 seedlings tested, chip color was acceptable in 17 and variable in 18. A group of 600 seedlings fromS. tuberosum parents treated comparably produced black-colored chips without exception.     

Der Baobab (Adansonia digitata L.): Wildobst aus Afrika für Deutschland und Europa?!

In Germany and Europe exotic fruits from distant places are becoming more and more important. In the tropics and subtropics an enormous variety of edible fruits exists. In 2008 the dry fruit pulp of the baobab (Adansonia digitata L.) was approved as novel food for the EU and thus entered the formal food market. Hence, an increasing number of products became available in Europe. The baobab is an impressive tree in the savannas of Africa. Due to its dense and wide spreading root system and its enormous water storing capacity in the stem, the tree can grow under very dry environmental conditions. In many regions of Africa it is a multipurpose indigenous fruit tree species which offers shelter and provides food, fodder and medicine as well as raw material for many purposes. However, even in Europe a wide range of products is now available as shown in the present study, which identified more than 300 baobab products or products with baobab as an ingredient. In Germany, not only the natural baobab pulp but also ready-made foodstuffs such as soft drinks, sandwich spreads, cereal bars, sweets and chocolates are available. Furthermore, a diverse range of pharmaceutical and cosmetic products with extracts from the baobab is available in the market. The products range from after shave and perfume to shampoo and shower gel to leg lotion and foot spray. In Germany baobab saplings and seeds are offered for planting and cultivation as an indoor pot plant. Commercially marketed baobab bonsai seedlings for the European market are produced in Senegal. In Africa the baobab fruits are mainly harvested from wild stands. However, the commercial production of baobab fruits in orchards could be an important future opportunity for income generation to many local households. More research on baobab, including the domestication of this wild fruit tree species, and the conservation of its natural stands as important genetic resource are prerequisites for sustainably increased fruit production.     

Detection of exotic QTLs controlling nitrogen stress tolerance among wild barley introgression lines

Nitrogen (N) is one of the most important plant nutrients, controlling growth and, ultimately, yield of a cultivar. Hordeum vulgare ssp. spontaneum, the wild barley progenitor of cultivated barley, is known to possess genes that can improve tolerance against biotic and abiotic stresses. A quantitative trait locus (QTL) study with two levels of N fertilization was conducted under glasshouse in order to locate wild barley alleles that improve N stress tolerance in the genetic background of an elite barley cultivar. For this, a set of 28 barley introgression lines (S42ILs), which originate from the cross ??Scarlett???×???ISR42-8??, was studied. The S42ILs, containing single or multiple wild barley introgressions, and ??Scarlett?? were evaluated in regard to a total of 15 traits, related to morphological parameters, grain parameters as well as to carbon (C) and N content parameters. A mixed model analysis and a subsequent Dunnett test was conducted to identify S42ILs that significantly deviate from the recurrent parent ??Scarlett??, either tested separately for each N level, or simultaneously across both N levels. In total, 65 QTLs were detected for the S42IL set. Most QTLs were found for chlorophyll content during heading (10 QTLs) and the fewest for C/N ratio of straw (1 QTL). The individual S42ILs possessed different numbers of QTLs. For S42IL-108, a maximum of eight QTLs were found whereas S42IL-145 did not show any significant difference from ??Scarlett??. Wild barley alleles revealed decreasing effects at 32 QTLs and increasing effects at 33 QTLs. Although 25 QTLs exhibited similar effects across both N levels, 18 and 22 QTLs exhibited effects that were only detected under N0 or N1, respectively. We, thus, conclude that it may be worth to select improved barley cultivars for N stress tolerance separately under low N fertilization, rather than extrapolating trait performances from experiments carried out under standard N fertilization conditions. A number of wild barley QTL alleles improved N stress tolerance. For example, a wild barley QTL allele on chromosome 4H, present in the Hsp introgression of S42IL-119, was associated with a 13.0?% increase of thousand grain weight across both N levels and a 20?% increase under low N supply. QTLs detected in the present study were compared with those of previous field studies of the same cross and with other QTL studies in barley and other small grains. Accordance between QTL studies (QTLs showing similar effects at the same map location) is documented and discussed. Based on our study, promising wild barley QTL alleles are available in S42ILs, which can be readily utilized to select for improved N use efficiency in barley breeding.     

Smart spatial incentives for market-based conservation

Market-based instruments such as payments, auctions or tradable permits have been proposed as flexible and cost-effective instruments for biodiversity conservation on private lands. Trading the service of conservation requires one to define a metric that determines the extent to which a conserved site adds to the regional conservation objective. Yet, while markets for conservation are widely discussed and increasingly applied, little research has been conducted on explicitly accounting for spatial ecological processes in the trading. In this paper, we use a coupled ecological-economic simulation model to examine how spatial connectivity may be considered in the financial incentives created by a market-based conservation scheme. Land use decisions, driven by changing conservation costs and the conservation market, are simulated by an agent-based model of land users. On top of that, a metapopulation model evaluates the conservational success of the market. We find that optimal spatial incentives for agents correlate with species characteristics such as the dispersal distance, but they also depend on the spatio-temporal distribution of conservation costs. We conclude that a combined analysis of ecological and socio-economic conditions should be applied when designing market instruments to protect biodiversity.