RESULTS
Genetic diversity
Across all samples of S. brunoniana, the two primer
pairs generated a total of 234 reliable bands that ranged
from 99 to 502 bp in size, of which 221 (94.4%) were
polymorphic. The percentage of polymorphic bands (PPB)
at population level ranged from 73.9% (K) to 85.0% (B),
with 80.6% on average. Nei’s gene diversity within populations
(Hs) was 0.281 and at species level (Ht
) was 0.333.
Shannon’s information index was 0.419 at average intrapopulation
level (Hpop) and was 0.499 at species level (Hsp).
Among the ten populations, population F had the highest
genetic diversity, with He= 0.304 and I= 0.452, while population
K exhibited the lowest diversity, with He= 0.262
and I= 0.391. According to their geographical distribution,
when dividing the ten populations into two groups, the
Yunnan group possessed 91.9% of PPB, while the HainanLaos
group held 94.4% of PPB. Nei’s gene diversity
within the regions Yunnan and Hainan-Laos was 0.316 and
0.307, respectively; and Shannon’s information index was
0.474 and 0.466, respectively. Based on the latter two parameters,
S. brunoniana distributed in Yunnan had slightly
more genetic diversity than that in Hainan-Laos. Details
are shown in Table 1