Sequence characteristics of ITS 1 and ITS 2
The findings reported here identify ITS 1 and ITS 2 regions
of Nymphaea as having high sequence divergence and
G ? C content (%). Although ITS 1 is longer than ITS 2 in
sequence length (Table 3), the G ? C content in ITS 2
(50.2–51.5%) is relatively higher compared to ITS 1
(45.5–48.4%). This is in conformity with an earlier report
that identified angiosperm nrDNA ITS 2 sequences as GC
rich (Hershkovitz and Zimmer 1996). A similar case was
observed in Nuphar (belonging to Nymphaeaceae, Padgett
et al. 1999) and Hedysarum (Chennaoui et al. 2007) where
both ITS 1 and ITS 2 recorded more than 50% G ? C
content, with ITS 2 having a relatively higher G ? C
proportion. Remarkably, presumed functional ITS paralogs
of Cycas species recorded 64.4 and 65.2% G ? C content
for ITS 1 and ITS 2, respectively (Xiao et al. 2010). Recent
studies on fig cultivars (Ficus carica L.), however, revealed