Search Results (3)

The Asteraceae family in Siberian Asia exhibits remarkable biodiversity and has long served as a valuable resource for domesticating various beneficial plants with medicinal, therapeutic, and industrial significance to humanity. In this work, we studied for the first time the chemical composition of six understudied or previously unexplored plant species, Artemisia jacutica (AJ), Carduus nutans subsp. leiophyllus (CL), Cirsium heterophyllum (CH), Echinops davuricus (ED), Ixeris chinensis subsp. versicolor (IV), and Lactuca sibirica (LS), which were successfully cultivated under open-field conditions as biennial or perennial crops. We profiled these species, employing a liquid chromatography–mass spectrometry approach, identifying over 100 phenolic compounds. Among these compounds were hydroxybenzoic acid glucosides, hydroxybenzoyl/p-coumaroyl/feruloyl quinic acids, hydroxycoumarin O-glucosides, caffeoyl/p-coumaroyl/feruloyl glucaric/tartaric acids, O- and C-glucosides of apigenin, acacetin, luteolin, chrysoeriol, 6-hydroxyluteolin, pectolinarigenin, kaempferol, quercetin, isorhamnetin, and tri-/tetra-O-p-coumaroyl spermines and spermidines. All examined species exhibited a significant accumulation of phenolic compounds throughout the experimental period, reaching levels comparable to or exceeding those found in wild samples (WSs), with the best total phenolic content for AJ at 26.68 mg/g (vs. 26.68 mg/g in WS; second year), CL at 50.23 mg/g (vs. 38.32 mg/g in WS; second year), CH at 51.14 mg/g (vs. 40.86 mg/g in WS; sixth year), ED at 86.12 mg/g (vs. 78.08 mg/g in WS; seventh year), IV at 102.49 mg/g (vs. 88.58 mg/g in WS; fourth year), and LS at 127.34 mg/g (vs. 110.64 mg/g in WS; fifth year). Notably, in the first year of cultivation, approximately 40–60% of the wild-level target compounds accumulated in the plants, with even higher levels detected in subsequent years, particularly in the second and third years. This study highlights the potential of cultivation to produce new Asteraceae plants rich in bioactive phenolics. Full article

Climate warming is likely to change the ways in which plants interact with their insect mutualists, for example through changes in phytochemistry. In particular, this may have implications for the ways in which we manage noxious weeds, which may spread more quickly if they experience stronger mutualistic interactions. We grew the invasive nodding thistle, Carduus nutans, in two experimental treatments in the field: either passively warmed with open top chambers or at ambient temperatures. We collected pollen from thistles in each treatment and analysed the total protein, lipid, and carbohydrate content. We observed no difference in the pollen protein or carbohydrate content, but the total lipid content of the pollen was significantly higher in warmed plants. We conducted a total of 12.75 h of observations of putatively mutualistic, flower-visiting insects. In addition, we spent 4.17 h collecting bees that visited thistle inflorescences in the treatments, allowing us to identify them to species. We found a significant increase in the abundance of flower-visiting insects in the observations, but not bee abundance in collections. In addition, there was no treatment effect on the number of flower-visiting morphotypes in the observations, or bee species richness in the collections. However, a nonparametric test did identify a significant effect of warming on the composition of flower-visiting morphotypes in observations and bee species in collections. Overall, the warming treatment significantly increased lipid content of the pollen, but had relatively weak effects on insect visitation patterns. However, these effects may be amplified at larger spatial and temporal scales or higher temperatures. Full article

Remote detection of non-native invasive plant species using geospatial imagery may significantly improve monitoring, planning and management practices by eliminating shortfalls, such as observer bias and accessibility involved in ground-based surveys. The use of remote sensing for accurate mapping invasion extent and pattern offers several advantages, including repeatability, large area coverage, complete instead of sub-sampled assessments and greater cost-effectiveness over ground-based methods. It is critical for locating, early mapping and controlling small infestations before they reach economically prohibitive or ecologically significant levels over larger land areas. This study was designed to explore the ability of hyperspectral imagery for mapping infestation of musk thistle (Carduus nutans) on a native grassland during the preflowering stage in mid-April and during the peak flowering stage in mid-June using the support vector machine classifier and to assess and compare the resulting mapping accuracy for these two distinctive phenological stages. Accuracy assessment revealed that the overall accuracies were 79% and 91% for the classified images at preflowering and peak flowering stages, respectively. These results indicate that repeated detection of the infestation extent, as well as infestation severity or intensity, of this noxious weed in a spatial and temporal context is possible using hyperspectral remote sensing imagery. Full article