Response mechanism of growth and gypenosides content for Gynostemma longipes cultivated at two altitude habitats to fine root morphological characteristics.

Introduction: Fine roots are the critical functional organs of plants to absorb water and nutrients from the soil environment, while the relation between fine root morphological characteristics and yield & quality has received less attention for medicinal plants. Methods: Therefore, we investigated the relationship between fine root morphological characteristics and biomass & gypenosides content. We explored the primary environmental drivers of fine root indicators for Gynostemma longipes from three provenances cultivated at two altitude habitats. Results: At the end of the growing season, compared with the low-altitude habitat, the underground biomass of G. longipes in the high-altitude habitat increased significantly by 200%~290% for all three provenances. The response of gypenosides content to different altitude habitats varied with provenance and plant organs. The biomass of G. longipes strongly depended on the fine root characteristic indicators (P < 0.001), fine root length density, and fine root surface area. Our results also showed that the harvest yield of G. longipes could be effectively increased by promoting the growth of fine roots per unit leaf weight (P < 0.001, R2 = 0.63). Both fine root length density and fine root surface area had strong positive correlations with soil nutrient factors (R2 > 0.55) and a strong negative correlation with soil pH (R2 > 0.48). In a word, the growth of G. longipes is strongly controlled by the fine root morphological characteristics through the response of fine roots to soil nutrient factors and pH. Discussion: Our findings will help to deepen the understanding of the root ecophysiological basis driven by soil factors for the growth and secondary metabolites formation of G. longipes and other medicinal plants under changing habitat conditions. In future research, we should investigate how environmental factors drive plant morphological characteristics (e.g., fine roots) to affect the growth & quality of medicinal plants over a longer time scale.

The Complete Chloroplast Genomes of Gynostemma Reveal the Phylogenetic Relationships of Species within the Genus.

Gynostemma is an important medicinal and food plant of the Cucurbitaceae family. The phylogenetic position of the genus Gynostemma in the Cucurbitaceae family has been determined by morphology and phylogenetics, but the evolutionary relationships within the genus Gynostemma remain to be explored. The chloroplast genomes of seven species of the genus Gynostemma were sequenced and annotated, of which the genomes of Gynostemma simplicifolium, Gynostemma guangxiense and Gynostemma laxum were sequenced and annotated for the first time. The chloroplast genomes ranged from 157,419 bp (Gynostemma compressum) to 157,840 bp (G. simplicifolium) in length, including 133 identical genes: 87 protein-coding genes, 37 tRNA genes, eight rRNA genes and one pseudogene. Phylogenetic analysis showed that the genus Gynostemma is divided into three primary taxonomic clusters, which differs from the traditional morphological classification of the genus Gynostemma into the subgenus Gynostemma and Trirostellum. The highly variable regions of atpH-atpL, rpl32-trnL, and ccsA-ndhD, the repeat unilts of AAG/CTT and ATC/ATG in simple sequence repeats (SSRs) and the length of overlapping regions between rps19 and inverted repeats(IRb) and between ycf1 and small single-copy (SSC) were found to be consistent with the phylogeny. Observations of fruit morphology of the genus Gynostemma revealed that transitional state species have independent morphological characteristics, such as oblate fruit and inferior ovaries. In conclusion, both molecular and morphological results showed consistency with those of phylogenetic analysis.

Effects of different harvesting times and processing methods on the quality of cultivated Fritillaria cirrhosa D. Don.

Fritillaria cirrhosa D. Don is the major source plants of traditional Chinese medicine Fritillariae Cirrhosae Bulbus (FCB). Domestication, introduction, and cultivation is an important strategy to alleviate the shortage of endangered medicinal plants of F. cirrhosa. However, until now, the yield and quality changes of FCB in different harvest periods and drying treatments after harvest were not well understood. Therefore, in this paper, we investigated the yield and quality of cultivated F. cirrhosa at different harvest periods and postharvest processing methods. The results showed that dry weight per bulb ranged from 0.8913 to 1.4681 g and reached the highest at the wilting stage. The soluble sugar content ranged from 0.075% to 0.127% and reached the highest at the wilting stage. The content of total alkaloids ranged from 0.088% to 0.218% and reached the highest at the late-flowering stage. The contents of peimisine, sipeimine, peimine, and peiminine were 0.01178%-0.02615%, 0%-0.01713%, 0%-0.00745%, and 0%-0.00621% and reached the highest at the late-flowering period, wilting period, young fruit period, and initial flowering period, respectively. For the two different postharvest processing methods, the contents of total alkaloids and the 16 main characteristic peaks did not exhibit significant differences. Still, the alkaloid contents of the oven drying after washing were slightly higher than the sun drying. In conclusion, the best harvest period is the wilting period of F. cirrhosa, and oven drying after washing is more beneficial to ensure the quality of FCB and improve productivity.