Simplified Genomic Data Revealing the Decline of Aleuritopteris grevilleoides Population Accompanied by the Uplift of Dry-Hot Valley in Yunnan, China.

Understanding the evolutionary history of endangered species is crucial for identifying the main reasons for species endangerment in the past and predicting the changing trends and evolutionary directions of their future distribution. In order to study the impact of environmental changes caused by deep valley incision after the uplift of the Qinghai-Tibet Plateau on endangered species, we collected 23 samples belonging to four populations of Aleuritopteris grevilleoides, an endangered fern endemic to the dry-hot valleys (DHV) of Yunnan. Single-nucleotide variation sites (SNPs) were obtained by the genotyping-by-sequencing (GBS) method, and approximately 8085 SNP loci were identified. Through the reconstruction and analysis of genetic diversity, population structure, population dynamics, evolution time, and ancestral geographical distribution, combined with geological historical events such as the formation of dry-hot valleys, this study explores the formation history, current situation, reasons for endangerment and scientifically sound measures for the protection of A. grevilleoides. In our study, A. grevilleoides had low genetic diversity (Obs_Het = 0.16, Exp_Het = 0.32, Pi = 0.33) and a high inbreeding coefficient (Fis = 0.45). The differentiation events were 0.18 Mya, 0.16 Mya, and 0.11 Mya in the A. grevilleoides and may have been related to the formation of terraces within the dry-hot valleys. The history of population dynamics results shows that the diversion of the river resulted in a small amount of gene flow between the two clades, accompanied by a rapid increase in the population at 0.8 Mya. After that, the effective population sizes of A. grevilleoides began to contract continuously due to topographic changes resulting from the continuous expansion of dry-hot valleys. In conclusion, we found that the environmental changes caused by geological events might be the main reason for the changing population size of A. grevilleoides.

Over 30 Years of Misidentification: A New Nothospecies Lycoris × jinzheniae (Amaryllidaceae) in Eastern China, Based on Molecular, Morphological, and Karyotypic Evidence.

Based on the complete chloroplast genome, morphology, and karyotype evidence, we identified a new nothospecies, Lycoris × jinzheniae S.Y. Zhang, P.C. Zhang & J.W. Shao, in eastern China. This new nothospecies has been inappropriately named Lycoris × albiflora in the previous literature for more than 30 years. However, the new nothospecies resulted from the hybridization of L. sprengeri and L. chinensis and had the following characteristics: the karyotype was 2n = 19 = 3V + 16I, the leaves emerged in the spring, the ratio of filament to corolla length was approximately 1.2, tepals were slightly undulated and curved, and it was distributed throughout eastern China. These characteristics are quite different from those of L. × albiflora; thus, in this study, we named it and provided a detailed morphological description and diagnosis.

Lycorisinsularis (Amaryllidaceae), a new species from eastern China revealed by morphological and molecular evidence.

Lycorisinsularis S.Y.Zhang & J.W.Shao, a new fertile diploid species from coastal provinces in eastern China is described. This new species is most similar to L.sprengeri in morphology and has been misidentified as the latter for a long time. However, it can be distinguished from the latter by the relatively longer perianth tube (1.5‒2.5 cm vs. less than 1.3 cm), a characteristic that was overlooked before. Phylogenetic analysis, based on complete plastid genome, showed that L.insularis is not genetically related to L.sprengeri in the genus. The former was a sister group of L.sanguinea, while the latter was closely related to L.longituba and L.chinensis and they were respectively located on different clades that were separated at the base of the phylogenetic tree. The chromosome number of L.insularis is 2n = 22. At present, as the new species is relatively widely distributed and the wild population can normally reproduce by seeds, we evaluate it as LC (Least Concern) according to criteria of the IUCN Red List.

 Primulaxinningensis (Primulaceae), a new species from karst caves in Hunan, China.

Primulaxinningensis Wei Zhang bis & J.W.Shao, a new species from Hunan Province, China, is described. Its leaf morphology is similar to the P.merrilliana complex and flower morphology similar to P.cicutariifolia, but it can be distinguished from the former by the black pollen sac, corolla lobes apex obviously emarginate and can be differed from the latter by cotyledon triangular obovate, plants densely covered with glandular hairs and special habitat (karst caves). The whole plastid genome of this new species is 151, 601-151, 630 bp in length. Based on the whole plastid genome sequences, phylogenetic trees revealed that the new species did not genetically relate to the above two mentioned morphologically similar species, but it was closely related to P.hubeiensis. Currently, only three populations were discovered within a small distribution area, thus, it is preliminarily considered as Vulnerable (VU) according to criteria of the IUCN Red List.

Lycoris wulingensis, a dwarf new species of Amaryllidaceae from Hunan, China.

Lycoris wulingensis S.Y. Zhang, a new species from Hunan Province (central South China), is described and illustrated. This new species is a fertile diploid plant and its karyotype is 2n = 22. It is most similar to L. × haywardii in morphology, but the latter is a hybrid species and distributed in East China and the plant is much larger. Amongst the original species, L. wulingensis is similar to L. radiata, but differs from it in its flowers being rose-red (vs. red) and stamens and tepals are nearly the same length (vs. stamens significantly longer than tepals).

Pollen micromorphology of eastern Chinese Polygonatum and its role in taxonomy by using scanning electron microscopy.

Although considerable progress has recently been made in the taxonomic study of Asparagaceae, but the Polygonatum remains one of the most poorly investigated genus. Therefore, the present study was designed with the aim, to document the pollen micromorphology of closely related Polygonatum taxa and its taxonomic significance. Pollen micro-morphological features were observed using scanning electron microscopy-SEM). The pollen grains are monad, navicular, monocolpate, and radially symmetrical. A significant variation was observed in the exine sculpturing. Moreover, most of the Polygonatum taxa have perforate pollen while some of them were mixed with psilate to perforate, perforate to microreticulate, sometimes scabrate, gemmate with baculate. Hence, this study documented the pollen morphology of Polygonatum taxa and strengthens the taxonomic identification of the genus Polygonatum based on pollen characters, which helps and can be used as an additional tool for the correct identification and discrimination of the species of Polygonatum at generic and species level.

Evolution of Autonomous Selfing in Marginal Habitats: Spatiotemporal Variation in the Floral Traits of the Distylous Primula wannanensis.

Outcrossing plant species are more likely to exhibit autonomous selfing in marginal habitats to ensure reproduction under conditions of limited pollinator and/or mate availability. Distyly is a classical paradigm that promotes outcrossing; however, little is known about the variation in floral traits associated with distylous syndrome in marginal populations. In this study, we compared the variation in floral traits including stigma and anther height, corolla tube length, herkogamy, and corolla diameter between the central and peripheral populations of the distylous Primula wannanensis, and assessed the variation of floral traits at early and late florescence stages for each population. To evaluate the potential consequences of the variation in floral traits on the mating system, we investigated seed set in each population under both open-pollinated and pollinator-excluded conditions. The flower size of both short- and long-styled morphs was significantly reduced in late-opening flowers compared with early opening flowers in both central and peripheral populations. Sex-organ reciprocity was perfect in early opening flowers; however, it was largely weakened in the late-opening flowers of peripheral populations compared with central populations. Of these flowers, disproportionate change in stigma height (elongated in S-morph and shortened in L-morph) was the main cause of reduced herkogamy, and seed set was fairly high under pollinator-excluded condition. Our results provide empirical support for the hypothesis on the evolution of delayed autonomous selfing in marginal populations of distylous species. Unsatisfactory pollinator service is likely to have promoted reproductive assurance of distylous plants with largely reduced herkogamy mimicking "homostyles."

Foliar epidermal micromorphology and its taxonomic significance in Polygonatum (Asparagaceae) using scanning electron microscopy.

In the current investigation, 16 samples of six species of the genus Polygonatum were collected from different geographical regions in China. Leaf micromorphological traits were studied in detail using scanning electron microscopy. About five-leaf samples were used for each species collected from different geographical regions. A significant variation was found in the foliar epidermal traits such as stomata types and their distribution, epidermal cell shape, anticlinal wall pattern, and various types of trichomes. Polygonal epidermal cells were observed in P. cyrtonema, P. odoratum, P. sibiricum, and P. filipes, rectangular in P. zanlanscianense and P. odoratum and irregular shape in P. filipes and P. zanlanscianense. Straight anticlinal wall pattern was observed in most of the species, but straight to little undulate was observed in P. cyrtonema, P. filipes, and P. zanlanscianense. Similarly, various shape stomata that are, oval, oblong, and elliptical and types that is, paracytic, anomocytic, and actinocytic have been observed. Based on the foliar traits, the P. odoratum and P. sibiricum were found closely related to one another. On the other hand, P. involucratum and P. zanlanscianense shows a strong association. However, P. filipes showed very less similarity with the other five species. Hence this study adds useful information that may be helpful in the further taxonomic classification of the taxa at subspecies level and was found significant in the correct identification and discrimination of the closely related taxa of the genus Polygonatum.

Comparison Among Five Eucalyptus Species Based on Their Leaf Contents of Some Primary and Secondary Metabolites.

BACKGROUND: Eucalyptus belongs to the Myrtaceae family. It is the most planted hardwood forest crop worldwide, representing a global renewable resource of fiber, pharmaceuticals and energy. OBJECTIVE: To compare the five species, E. maidenii, E. robusta, E. citriodora, E. tereticornis and E. camaldulensis, seeking for the richest source of nutrients and pharmaceuticals. METHODOLOGY: Eucalyptus samples were subjected to some chemical determinations for both primary and secondary metabolites to verify their nutritional and pharmaceutical importance related to different extracts. GC-MS analysis was applied to detect the presence of some individual phenolic constituents in their leaves. RESULTS: E. robusta recorded the maximum contents of carbohydrates (40.07%) and protein (31.91%). While E. camaldulensis contained the highest contents of total phenolic compounds (46.56 mg/g), tannins (40.01 mg/g) and antioxidant activities assayed by the phosphomolybednum method (57.60 mg/g), followed by E. citridora. However, E. tereticornis exhibited the highest reducing power ability (151.23 mg/g). The GC-MS highlighted 20 phenolic constituents and antioxidants which varied in their abundance in Eucalyptus leaves, 8 individual phenolics (hydroquinone, hesperitin, pyrogallol, resorcinol, protocatechuic acid, naringenin, chlorogenic acid and catechin) were maximally recorded with E. camaldulensis and secondly, with E. citridora in case of at least 5 components. Nevertheless, gallic and quinic acids were more abundant in the leaves of E. tereticornis, which may explain its high corresponding reducing powers. CONCLUSION: Acetone-water combination has enhanced phenolics extraction from Eucalyptus tissues. This is the first report aiming to compare between the aforementioned Eucalyptus species highlighting either their nutritional or medicinal importance.

Intraspecific variation of self-incompatibility in the distylous plant Primula merrilliana.

Heteromorphic self-incompatibility can prevent self- and intramorph fertilization while favouring intermorph mating and the maintenance of morph-ratio stability in heterostylous populations. However, variation in the expression of self-incompatibility intraspecies has seldom been assessed. Through hand pollinations and microsatellite markers, the variation in the expression of self-incompatibility and genetic diversity were studied in distylous plant Primula merrilliana. We discovered that the strength of self-incompatibility varied extensively among individuals and populations, from pronounced to weaker self-incompatibility in distylous populations, all the way to strong self-compatibility in homostylous populations. Each distylous population included self-incompatible (SI), partly self-compatible (PSC) and self-compatible (SC) individuals, with the index of self-compatibility (ISC) ranging from 0.07 to 0.68 across populations. Self-compatible populations (ISC > 0.25) were not genetically clustered but were more closely related to populations with high SI and SC individuals were mixed with SI individuals within populations. The ISC and the proportions of SC and PSC individuals were higher in peripheral than in central populations, but no decrease of genetic diversity and no deviations of floral morph ratio from isoplethy were detected in peripheral populations. Additionally, the expression of self-incompatibility was stronger in long-styled flowers than in short-styled flowers. The variation in the strength of self-incompatibility documented in P. merrilliana cautions against the estimation of ISC from a few individuals or populations in distylous species and provides a more complex and nuanced understanding of the role of self-incompatibility in heterostyly.

Effects of population size on reproductive success of the endangered and endemic species Primula merrilliana.

The reproductive ability related to the population size of the endangered and endemic species Primula merrilliana Schltr. was investigated. In 26 populations observed, only four contain more than 500 flowering individuals, whereas most of them (53.8%) consist of less than 100 flowering individuals. Though the ratio of pin and thrum plants keeps its balance at 1:1 for all populations, the frequency of pin and thrum flowers was significantly biased in most small populations. Population size strongly affected reproductive success; plants in small populations produced significantly fewer flowers and fruits per plant and fewer seeds per fruit, and therefore fewer seeds per plant. The floral density was another important factor that influenced the reproductive success of P. merrilliana, because four main reproductive success parameters (fruits per plant, seeds per fruit, seeds per plant, and the proportion of flowers setting fruit) were all positively correlated with floral density. The size of plants and the number of leaves per plant (measure of habitat quality) were not influenced by the variation of population size, suggesting that the reduced fecundity in small populations may not be a consequence of lower habitat quality. Inbreeding depression and pollen limitation as a result of less attractiveness in small populations are therefore likely explanations for these patterns.