Chemical Constituents in Hybrids of Ligularia tongolensis and L. cymbulifera: Chemical Introgression in L. tongolensis

Abstract

Two samples with morphologies intermediate between Ligularia tongolensis and L. cymbulifera were collected in Desha, Sichuan Province, and one, in Pachahai, Yunnan Province, P. R. China. The DNA sequencing confirmed that the samples were hybrids of the two species. Tetradymol (1), the major compound of L. cymbulifera not found in L. tongolensis, was isolated from the hybrid samples collected at both locations, while furanoeremophilan-15-oic acid derivative 4, a compound characteristic to L. tongolensis, was found in the Pachahai hybrid but not in the Desha hybrids. Thus, the chemical consequence of hybridization can be variable. In addition, analysis of L. tongolensis samples at Pachahai indicated that introgression has been a mechanism of generating chemical diversity in the plant. Eleven compounds including three new ones were isolated.

Diversity of Furanoeremophilane Composition in Ligularia tongolensis

“…4 Hybrids of L. tongolensis and L. cymbulifera were also analyzed and the ability to produce tetradymol in L. tongolensis was inferred to have been introgressed from L. cymbulifera. 6 In the course of our subsequent search in the field, we collected 32 additional samples of L. tongolensis. Seven of the samples (samples 1-7), collected in 2015 to 2017 at locations shown in Table 1 and Figure 1, were analyzed in detail.…”

“…Sample 3 was collected at Pachahai, Shangrila County, Yunnan, where the above hybrid samples were collected. 6 Sample 4 was collected at Tianchi, Shangrila County, where we collected various Ligularia hybrids, for which the chemical outcomes of hybridization were described. [7][8][9] Samples 5, 6 (4 km apart from each other), and 7 were collected in Muli County, Sichuan.…”

“…As we discussed previously, it indicates hybridization with some other species. 6 Since the morphology of the sample is of L. tongolensis, it must have undergone backcrossing; namely, it is introgressed. The bases at these sites cannot be accounted for by the superposition of L. tongolensis and L. cymbulifera sequences ( Table 3).…”

Chemical Composition of Intergeneric Hybrids Between Ligularia and Cremanthodium Collected in Sichuan Province of China

“…[4][5][6][7][8] Chemical characterization has revealed a variety of outcomes of hybridization. [9][10][11][12][13][14][15] In some cases, both parents contributed compounds to their offspring; in some, the chemical contribution was only from one parent; in others, hybridization appeared to have engendered compounds that were absent in their parents. 9,[12][13][14] In addition, introgression has been revealed by DNA analysis 10,12,15,16 and inferred to be behind the presence of the compounds that are detected only in some populations within a species.…”

“…9,[12][13][14] In addition, introgression has been revealed by DNA analysis 10,12,15,16 and inferred to be behind the presence of the compounds that are detected only in some populations within a species. 12,17 These results show that hybridization is important in the chemical evolution of Ligularia in the Hengduan Mountains area.…”