Abstract: |
The genus Cassia and Senna have been classified under subfamily Caesalpinioideae of family Fabaceae (Leguminosae)
of order Fabales. There is a scarce taxonomical studies of the genus Cassia and Senna inhabiting Egyptian environments,
thus, the main objective of the current was to revise and authenticate the phylogenetic relationship between
studied taxa of the species of the genera Cassia and Senna in Egypt using the recent tools of ITS barcoding, RAPD
analysis and metabolic profiling, in comparing to the traditional taxonomical features. From the cluster analysis of
the traditional 27 morphological characters, the studied taxa were categorized into two major clades with an average
taxonomic distance of 4.3. The clade I include Cassia fistula, C. renigera, C. javanica L subsp. nodosa and C. roughiia
that belongs to series Obolospermae, and C. grandis that belongs to series Grandes. The clade (II) includes Senna
surattensis and S. alata at taxonomic level 3.6. The taxonomical description of the studied taxa was confirmed from
the molecular analysis of ITS sequences and RAPD analysis. The ITS sequences of the tested plants species C. fistula
L, C. grandis MD4, C. javanica subsp. nodosa MD7, C. roxburghii MD5, C. renigera MD5 were deposited at genbank
with accession numbers MW367973, MZ960447, MW386305, MW326753 and MW32685, respectively. While, the ITS
sequences of the S. surrattensis and S. alata were deposited into genbank accession # MD14 MW367670 and MD20
MW412635, respectively. Thus, from the molecular analysis, two clades were clearly separated into Clade I of Cassia
and Clade II of Senna. The cluster I represented by C. fistula, C. renigera, C. roxburghii, and C. javanica sub nodosa, and
the cluster II represented by S. alata and S. surattensis. From the PCA of RAPD, a clearly discrimination between the
two Taxa was observed revealing the characteristic grouping of Cassia and Senna. The species Senna alata and Senna
surattensis were grouped together, but the species of C. renigera, C. javanica, C. roxburghii and C. grandis was grouped
on a distinct group. The separation of Cassia and Senna species into two clusters verify the segregation of the genus
Cassia L. senso lato into two distinct genera namely Senna P. and Cassia L. The morphological, molecular traits of the
studied plants were authenticated from the metabolic profiling by GC-MS analysis. Among the 23 identified metabolites,
four compounds namely hexadecanoic acid, methyl ester, 9-Octadecenoic acid (Z)-ethyl ester and Vitamin E
were detected with fluctuated concentrations, among C. fistula, C. grandis, C. javanica subsp. nodosa and C. roxburghii.
Conclusively, the traditional morphological features, molecular barcoding using ITS sequences, RAPD analysis and
metabolic traits by GC-MS analysis, authenticates the taxonomical diversity of the genus Cassia and Senna.
|
|
|