Background: Paeonia decomposita, endemic to China, has important ornamental, medicinal, and economic value and is regarded as an endangered plant. The genetic diversity and population structure have seldom been described. A conservation management plan is not currently available.Results: In the present study, 16 pairs of simple sequence repeat (SSR) primers were used to evaluate the genetic diversity and population structure. A total of 122 alleles were obtained with a mean of 7.625 alleles per locus. The expected heterozygosity (H_e) varied from 0.043 to 0.901 (mean 0.492) in 16 primers. Moderate genetic diversity (H_e = 0.405) among populations was revealed, with Danba identified as the center of genetic diversity. Mantel tests revealed a positive correlation between geographic and genetic distance among populations (r = 0.592,P = 0.0001), demonstrating consistency with the isolation by distance model. Analysis of molecular variance (AMOVA) indicated that the principal molecular variance existed within populations (73.48%) rather than among populations (26.52%). Bayesian structure analysis and principal coordinate analysis (PCoA) supported the classification of the populations into three clusters.Conclusions: This is the first study of the genetic diversity and population structure ofP. decompositausing SSR. Three management units were proposed as conservation measures. The results will be beneficial for the conservation and exploitation of the species, providing a theoretical basis for further research of its evolution and phylogeography.

Background: Small populations are predominantly vulnerable to inbreeding and inbreeding depression (ID). Owing to increased levels of inbreeding on individuals in small populations, ID could decrease the population growth rate, as well as its effective size, and exacerbate the extinction risk. Inbreeding depression remains a crucial area of research in conservation biology, ecology, and evolutionary biology. This study aims to elucidate the reproductive biology, inbreeding, and ID ofPaeonia decompositaand to conserve, manage, and improve them better in the future.Results: Paeonia decompositabelongs to a xenogamous category and is partially self-compatible; moreover, it requires pollinators for seed production. Lately, the occurrence of pollination and pollinator limitations has affected the seed set. Low seed set primarily correlated with an abnormality of meiosis in the pollen mother cell, moderate to low genetic diversity, drought and extreme weather, pollinator limitation, or carpel space limit. One of the primary reasons for endangered mechanism inP. decompositais the low seed set under natural conditions. The cumulative value of ID was positive, and outcrossed progeny outperformed selfed progeny.Conclusions: Paeonia decompositarequires pollinators to ensure seed production either through autogamy, geitonogamy, or allogamy. It is both allogamous and partially self-compatible, as well as a successful outcrosser. Inbreeding occurs frequently and results in ID, which imposes a potential threat to the survival of populations. Besides, it needs conservation via in situ andnatural returnmethods.

The chromosome number and karyotype of three populations in Paeonia intermedia C.A. Mey are presented in this paper. The populations, sampled from Altai Prefecture in Xinjiang, China, are diploids (2n = 10), with 2A type karyotype and the karyotypic formula of 2n = 2x = 10 = 6m + 2sm + 2st. There was no obvious differentiation among all the three sections of the genus Paeonia based on parameters of arm ratio and ratio of the longest/shortest chromosome (L1/Ln). There is merely slight difference between the woody section (Sect. Moutan) and the herbaceous sections (Sects. Onaepia and Paeonia). DOI: http://dx.doi.org/10.3329/bjb.v43i1.19758 Bangladesh J. Bot. 43(1): 101-105, 2014 (June

Paeonia decomposita, endemic to China, has important ornamental, medicinal and economic value and is regarded as a threatened endangered plant. The genetic diversity and structure have seldom been described. A conservation management plan is not currently available. In present study, 16 pairs of SSR primers were used to evaluate genetic diversity and population structure. A total of 122 alleles were obtained with a mean of 7.625 alleles per locus. The expected heterozygosity (He) varied from 0.043 to 0.901 (mean 0.492). Moderate genetic diversity (He=0.405) among populations were revealed, with Danba identified as the center of genetic diversity. Mantel tests revealed a significant positive correlation between geographic and genetic distance among populations (r=0.592, P=0.0001), demonstrating consistency with the isolation by distance model. Analysis of molecular variance (AMOVA) results indicated that the principal genetic variation existed within populations (73.48%) rather than among populations (26.52%). Bayesian structure analysis and principal coordinate analysis (PCoA) supported classification of the populations into three clusters. Based on the level of observed genetic diversity, three management unints were proposed as conservation measures. The results will be beneficial for the conservation and exploitation of the species, providing a theoretical basis for further research on its evolution and phylogeography.Hightlights: Genetic diversity among populations was moderate inPaeonia decomposita There is significant positive correlation between geographic and genetic distance among populations, consistent with the isolation by distance model Principal genetic variation existed within populations rather than among populations. The populations divided into three clusters. Three management unints were proposed as conservation measures.

Sonneratia ovata is one of the most widely distributed mangrove species worldwide. In this study, the complete chloroplast (cp) genome of S. ovata was sequenced and assembled; its phylogenetic position was confirmed in Lythraceae. The total size of cp genome was 153,052 bp, exhibiting a typical quadripartite structure with a large single copy (LSC) region of 87,238 bp and a small single copy (SSC) region of 18,002 bp, two inverted repeats (IRs) regions of 23,906 bp each. The overall GC content was 37.3%, respectively. We detected 128 genes in cp genome, including 84 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. A phylogenetic analysis showed that S. ovata has a close relationship with S. apetala within the genus Sonneratia.

Chromosomal meiotic behaviour in pollen mother cells (PMCs) of Paeonia anomala subsp. veitchii, endemic to China, was investigated in three natural populations represented by 14 individuals. Meiotic abnormalities including bridges, fragments and univalents occurred in all individuals. At metaphase I, mean chromosome configuration of each cell was 2n = 10 = 0.36 I + 4.82 II. Most of the chromosomes were ring bivalents, but some were rod bivalents or univalents. Pairing index ranged from 71.04 to 77.76%. Chromosome bridges, fragments, unequal separation and lagging chromosomes were observed both at anaphase I and telophase I. All individuals produced bridges/fragments (10.37% of PMCs on average) at anaphase I, which suggested that they were all heterozygotes for paracentric inversions. However, there were some variations among individuals in frequency of bridge occurrence and size of fragments, which indicated that many different inversions existed in this subspecies. Further evidence is needed to answer why the structural heterozygosity exists so widely in the subspecies, and whether there is a relationship between this structural heterozygosity and ecological adaptation.