Background: Bulb rot causes loss of the perennial medicinal plant Fritillaria przewalskii Maxim., is exacerbated with growth years and seriously constrains plant productivity, but the pathogens responsible for the disease were still unknown, very few reports were presented before.Methods: To determine potential pathogenic sources, fungus strains were isolated from diseased plant samples with bulb rot symptom of the 3- to 5-year-old F. przewalskii plants by tissue separation, and assayed for pathogenicity according to Koch’s Law.Results: Seven pathogenic strains (F1-F7) were detected in5-year-old rot bulbs, six (F1-F6) in 4-year-old rot bulbs, and four (F1, F2, F5, F6) in 3-year-old rot bulbs. All of the strains were able to infect bulbs by stabbing and some exhibited varying levels of aggressiveness. Relative to the non-stabbing controls, the bulbs stab-inoculated with F5, F2, F7, F4, F1, F6, and F3 showed 76.65%, 75.15%, 71.44%, 40.37%, 39.09%, 36.87%, and 34.93% rot after 8 days, respectively. Phylogenetic analysis revealed that theses trains (deposited in GenBank under accessions MH917682 to MH917688) were clustered into Bionectria ochroleuca (F1, F3, F4), Fusarium oxysporum (F2, F7), Fusarium tricinctum (F5), and Clonostachys rosea (F6). The two species of Fusarium had the strongest pathogenicity, followed by Bionectria ochroleuca and Clonostachys rosea. Although leading to low bulb rot incidence by stab-inoculation, F1 showed the highest isolation rate (48.9%) among all strains. Conclusions: Thus, the edible and medicinal bulbs of F. przewalskii are susceptible to synergetic contamination by these seven pathogenic strains at some point after their third year of growth, which has contributed to the species endangered status, with the two strains of Fusarium being the predominant pathogens. To our knowledge, this is the first report on the seven strains of four fungal species causing in F. przewalskii bulb rot in China.

Polygonatum cyrtonema is a perennial plant, and it has long been used in traditional Chinese medicine for food and medicine. The medicinal part of Polygonatum cyrtonema is the underground rhizome; however, the aerial part has not been studied so far for its medicinal activity. To promote the growth of underground rhizomes, the topping of aboveground plants of Polygonatum cyrtonema has been conducted. To understand the effect of the topping of aerial parts on the yield and medicinal components of rhizomes, the present study was conducted. Also, the chemical constituents, antioxidant, and in vitro hypoglycemic activities of the aerial stem, leave, and flower parts of Polygonatum cyrtonema were analyzed. The results showed that compared to the control (CK) treatment, the topping of the aerial part increased rhizome weight gain coefficient (3.43) significantly than the CK treatment (2.63). Moreover, the topping of the aerial part induces the biosynthesis of bioactive compounds. As such, the polysaccharide content in the rhizome (8.80%) and the total saponin content (37.60 mg/g) was significantly (P < 0.01) higher than CK treatment. The contents of total phenols and total flavonoids in PCL and PCF were significantly (P < 0.01) higher than those in rhizomes; however, the polysaccharide content (10.47%) in PCR (whole rhizome) was higher than that in PCS (3.65%), PCL (5.99%), and PCF (4.76%) content. The protein and amino acid contents in PCS, PCL, and PCF were higher than those in rhizomes. The protein and amino acid contents in PCS, PCL, and PCF were higher than those in rhizomes. PCS, PCL, and PCF showed strong antioxidant activities (DPPH, ·OH, ABTS, and FRAP), which were better than traditional medicinal parts ( the rhizome). To sum up, the topping measures can improve the rhizome yield of Polygonatum cyrtonema and the medicinal components of the rhizomes, which can be applied to improve production. The stems, leaves, and flowers had a much stronger antioxidant activity and higher the total polyphenols, flavonoids, proteins, and amino acid content. Therefore, stems, leaves, and flowers of Polygonatum can be fully developed according to different needs. they are typically used in animal feed, food storage and cosmetics.