Examining historical rates of leafcutting bee cell pathogens to establish baseline infectivity rates for alfalfa seed growers

The alfalfa leafcutting bee (Megachile rotundata) is one of the primary pollinators for the alfalfa seed industry. The alfalfa leafcutting bee is a solitary cavity nesting bee. Female Megachile rotundata bees will construct and provision individual brood cells lined with cut leaves (cocoon) and will gather nectar and pollen to place within the constructed cocoon. The female bee will lay a single egg within the constructed cocoon and leave the egg to undergo larval stage development and pupation into the adult stage. During this time multiple pathogens and parasitoids can prey on the developing larvae, resulting in the loss of the future adult bee. A major concern for commercial alfalfa seed growers is the presence of invertebrate pests and fugal pathogens. In the present study, we used historical data from the Parma Cocoon Diagnostic Laboratory to determine baseline rates of pathogen and parasite infection of Megachile rotundata cells and used this analysis to determine historical infection rates and cutoffs for management practices. Additionally, using a Faxitron (X-ray) analysis for Megachile rotundata cell obtained in 2020, we compared the presence of chalkbrood, pathogens, and parasitoids in samples collected from both growers stocks and newly purchased Canada bees. The results of the investigation demonstrate historical averages of the presence of chalkbrood, pathogens, and parasitoids. We also show a significant increase in chalkbrood and predators in 2007-2011 and a significant difference in chalkbrood and predators between bee samples obtained from Canada and grower stocks.

Influence of lead acetate on seed germination and growth of young alfalfa plants

This study presents the results of testing the effect of different concentrations of lead-acetate on seed germination and young Seedlings of alfalfa. Тhe experiment was organized so that in the first variant, only lead-acetate of different concentrations (10-5, 10-4, 10-3, 10-2 and 2 x 10-2 M) was used, and in the second, next to the lead acetate EDTA concentration of 0.012 % was added. The results of this study in which natural conditions are imitated showed that the percentage of alfalfa seed germination decreases with increasing lead-acetate concentrations. In a medium of high concentration of lead acetate 10-2 and 2 x 10-2, a small number of seeds (39% and 32 (32%) germinated. In the same treatments with EDTA, the toxic effects of lead acetate were reduced, and seed germination was better (59% and 43% seeds germinated). It has been noticed that lead has toxic effects on the growth of alfalfa roots and stems. In the variant in which EDTA was used, the negative influence of lead on and growth of alfalfa seedlings was significantly mitigated.

Influence of lead acetate on seed germination and growth of young alfalfa plants

This study presents the results of testing the effect of different concentrations of lead-acetate on seed germination and young Seedlings of alfalfa. Тhe experiment was organized so that in the first variant, only lead-acetate of different concentrations (10-5, 10-4, 10-3, 10-2 and 2 x 10-2 M) was used, and in the second, next to the lead acetate EDTA concentration of 0.012 % was added. The results of this study in which natural conditions are imitated showed that the percentage of alfalfa seed germination decreases with increasing lead-acetate concentrations. In a medium of high concentration of lead acetate 10-2 and 2 x 10-2, a small number of seeds (39% and 32 (32%) germinated. In the same treatments with EDTA, the toxic effects of lead acetate were reduced, and seed germination was better (59% and 43% seeds germinated). It has been noticed that lead has toxic effects on the growth of alfalfa roots and stems. In the variant in which EDTA was used, the negative influence of lead on and growth of alfalfa seedlings was significantly mitigated.

Wettability and Water Uptake Improvement in Plasma-Treated Alfalfa Seeds

The cultivation of alfalfa (Medicago sativa L.), a forage crop grown worldwide, is negatively affected by hard seed presence. We show that treatment of alfalfa seeds with an inductively coupled radio frequency oxygen plasma improves their surface hydrophilicity, as determined by water contact angle (WCA) measurements and water uptake. Furthermore, we see that these effects are mediated by functionalization and etching of the alfalfa seed surface. Surface chemistry is analyzed by X-ray photoelectron spectroscopy (XPS), while morphology is viewed using scanning electron microscopy (SEM). Plasma produces effective alfalfa seed hydrophilization with a variety of treatment parameters. With its potential for fine-tuning, plasma modification of seed wettability shows promise for introduction into agricultural practice.

Effect of Germination on Alfalfa and Buckwheat: Phytochemical Profiling by UHPLC-ESI-QTOF-MS/MS, Bioactive Compounds, and In-Vitro Studies of Their Diabetes and Obesity-Related Functions

Germination can be used to enhance nutritional value and health functions of edible seeds. Sprouts are considered healthier than raw seeds because they are richer in the basic nutritional components (carbohydrates, protein, vitamins, and minerals) and also contain more bioactive components responsible for various biological activities. The effect of sprouting on the antioxidant, antidiabetic, antiobesity activities, and metabolite profiles of alfalfa and buckwheat seeds was investigated in this study. DPPH radical scavenging activity was highest in buckwheat sprouts followed by alfalfa sprout, buckwheat seed, and alfalfa seed, respectively. ABTS radical scavenging potential showed a similar trend as DPPH with buckwheat sprouts exerting the best scavenging capacity. Alfalfa sprout and buckwheat seed exhibited the highest percentage inhibitory activity of α-glucosidase (96.6 and 96.5%, respectively). Alfalfa sprouts demonstrated the strongest inhibitory activity against pancreatic lipase (57.12%) while alfalfa seed showed the highest advanced glycation end products (AGEs) formation inhibitory potential (28.7%). Moreover, thirty-three (33) metabolites were characterized in the seed and sprout samples. Sprouts demonstrated a higher level of metabolites compared to raw seeds. Hence, depending on the type of seed and the target activity, sprouting is a good technique to alter the secondary metabolites and functional properties of edible seeds.

Non-Destructive Identification of Naturally Aged Alfalfa Seeds via Multispectral Imaging Analysis

Seed aging detection and viable seed prediction are of great significance in alfalfa seed production, but traditional methods are disposable and destructive. Therefore, the establishment of a rapid and non-destructive seed screening method is necessary in seed industry and research. In this study, we used multispectral imaging technology to collect morphological features and spectral traits of aging alfalfa seeds with different storage years. Then, we employed five multivariate analysis methods, i.e., principal component analysis (PCA), linear discrimination analysis (LDA), support vector machines (SVM), random forest (RF) and normalized canonical discriminant analysis (nCDA) to predict aged and viable seeds. The results revealed that the mean light reflectance was significantly different at 450~690 nm between non-aged and aged seeds. LDA model held high accuracy (99.8~100.0%) in distinguishing aged seeds from non-aged seeds, higher than those of SVM (87.4~99.3%) and RF (84.6~99.3%). Furthermore, dead seeds could be distinguished from the aged seeds, with accuracies of 69.7%, 72.0% and 97.6% in RF, SVM and LDA, respectively. The accuracy of nCDA in predicting the germination of aged seeds ranged from 75.0% to 100.0%. In summary, we described a nondestructive, rapid and high-throughput approach to screen aged seeds with various viabilities in alfalfa.

Metabolomics and microbiome reveal impacts of rhizosphere metabolites on alfalfa continuous cropping

Alfalfa long-term continuous cropping (CC) can pose a serious threat to alfalfa production. However, the mechanism of alfalfa CC obstacle is unclear as of today. In this study, we determined physic-chemical property, microbial population structure, and metabolite differences of alfalfa rhizosphere soils with CC for 1, 7, and 14-years based on analysis of metabolomics and microbiomics. Shifts of functional microorganisms in rhizosphere soil were analyzed, key metabolites and their effects on alfalfa seeds, seedlings and root rot pathogens were assessed. Based on anlysis, p-coumaric acid and ferulic acid on alfalfa seed and seedling growth and root rot pathogens were basically consistent with the influence of CC obstacles in the field. With the increase of CC years, the microbial community in soils changed from fungal to bacterial, and beneficial microorganisms decreased with the increase of CC years, which echoed the performance of alfalfa CC obstacles. The autotoxicity of p-coumaric acid was the strongest.This study fully proved that the continuous accumulation of autotoxic substances in alfalfa rhizosphere was the key factor causing alfalfa CC obstacles.