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Lilium concolor var. pulchellum is a perennial herbaceous plant with high ornamental and edible value; it is a critical breeding parent of Asiatic hybrids. In this study, we reported the complete chloroplast genome of L. concolor var. pulchellum. The total size of the genome is 152,126 bp with a GC content of 37.0%. It has a conserved quadripartite structure comprising 136 genes, including 38 tRNA genes, 8 rRNA genes, 83 protein-coding genes, and 7 pseudogenes. Phylogenetic analysis strongly supported a close relation between L. concolor var. pulchellum and L. callosum. The complete plastome sequence of L. concolor var. pulchellum could provide useful information for phyletic evolution of the genus Lilium. [ABSTRACT FROM AUTHOR]

Petaloid stamens in Paeonia lactiflora constitute an important developmental phenomenon that explain double flower formation. Although research on stamen development in model plants has progressed considerably, the underlying molecular mechanism in P. lactiflora petaloid stamens is still unclear. In this study, acomparative transcriptomic analysis was performed on two cultivars of P. lactiflora ('Fen Yu Nu' and 'Lian Tai') with different stamen developmental patterns. Following transcriptome sequencing, 89,393 unigenes were identified in P. lactiflora. Trend analysis and weighted gene co-expression network analysis (WGCNA) indicated that 18 candidate genes were likely involved in the formation and development of petaloid stamens, including seven MADS-box genes, PlAP3, PlDEFA, PlPI2, PlAG-1, PlSEP3, PlSEP1-1, and PlSEP1-2, and 11 other transcription factors (TFs), PlTCP2, PlTCP4, PlTCP9, PlbHLH36, PlICE1, PlLBD38, PlNAC083, PlBLH11, PlPDF2, PlGBF1, and PlIIIA. Using these 18 selected candidate genes, we propose ahypothetical model of gene expression network that regulates the development of petaloid stamens. Our results provide acollection of candidate genes that are useful for the analysis of P. lactiflora petaloid stamens, allowing for in-depth studies of the development pattern of P. lactiflora flower organs, and providing atheoretical basis for related research on petaloid stamens of flowers in other herbaceous plants. [ABSTRACT FROM AUTHOR]

Zygotic embryos of three herbaceous peony (Paeonia lactifloraPall.) cultivars (‘Fen Yu Nu’, ‘Zhong Sheng Fen’ and ‘Zhu Sha Pan’) were used to study embryo germination and optimum plant growth regulator (PGR) combinations for in vitro propagation and root initiation. Mature zygotic embryos (>90 days after flowering [DAF]) gave better germination and survival than immature zygotic embryos (50–70 DAF). A protocol for initiating shoot growth and axillary shoot proliferation was established using mature embryos. The best results were obtained when using excised zygotic embryos (EZEs) obtained by removing the testa and endosperm from the seed. The best medium for EZE germination (an embryo with cotyledons) was half-strength Murashige and Skoog (MS) medium (with double-strength CaCl2) supplemented with 0.5 mg L?16-benzyladenine (BA) and 0.5 mg L?1gibberellic acid (GA3). The best medium for axillary shoot proliferation was half-strength MS medium (including double-strength CaCl2) supplemented with 1 mg L?1BA and 1 mg L?1GA3. PGR-free half-strength MS was the best medium for promoting root development on seedlings (a germinated EZE with tender leaves) and for robust in vitro seedling establishment. The acclimatization of herbaceous peony remains the most challenging step of the in vitro protocol. [ABSTRACT FROM AUTHOR]

Although herbaceous peony cultivars have been introduced and promoted widely, a key limitation to their use is their level of cold hardiness. In this study, the physiological and biochemical responses of six herbaceous peony cultivars to different temperatures and periods of exposure to freezing temperatures were assessed by analyzing changes in six indices. Under our experimental conditions, relative electric conductivity, soluble sugar concentration, soluble protein concentration, and malondialdehyde concentration generally increased as temperature declined, while proline content decreased. Superoxide dismutase activity fluctuated. After the same indicators were used to assess cold resistance over time at − 20 °C, the six cultivars could be ranked, in decreasing levels of cold resistance, as: ‘Da Fu Gui’, ‘Fen Yu Nu’, ‘Kansas’, ‘Monsieur Jules Elie’, ‘Taff’, and ‘Pink Hawaiian Coral’. [ABSTRACT FROM AUTHOR]

Abstract: Herbaceous peony, which belongs to sect. Paeonia, Paeonia L., Paeoniaceae, is not only a famous traditional flower in China; it is also highly regarded as an ornamental in Europe and the USA. On account of the abundance in germplasm resources and wide distribution ranges, herbaceous peony can be divided into three cultivar groups, the Chinese Peony Cultivar Group, the European Peony Cultivar Group and the Hybrid Peony Cultivar Group. However, most studies on genetic relationships in Paeonia are limited to the first group. This study used 15 polymorphic microsatellite markers that were developed by magnetic bead enrichment to explore the genetic diversity of 89 genotypes collected from Beijing, the USA and Canada and introduced to China. From 145 allelic loci that were detected from 15 primers, 140 (96.6%) were polymorphic. The number of allelic loci ranged from 4 to 16 with an average of 9.3, and the polymorphic index content ranged from 0.362 to 0.825 with an average of 0.678. Both cluster analysis and principal component analysis based on the 15 polymorphic primer pairs could distinguish the species from cultivars although the cluster analysis was better able to reflect the genetic relationships between all individuals. Some new insights about Paeonia L. are suggested. Furthermore, the 15 SSR markers have great significance as they will allow for furthering the studies on genetic diversity, genetic relationships and even the molecular marker-assisted breeding of Paeonia L. [Copyright &y& Elsevier]