Table of Contents

18 May 2015, Volume 53 Issue 3
Cover illustration: A new phylogenetic tree of the Campanulaceae s.s. showing all three tribes: tribe Campanuleae (Campanula), tribe Wahlenbergieae (Wahlenbergia), and tribe Cyanantheae; as well as the six subtribes of tribe Cyanantheae: subtribe Platycodoninae (Platycodon), subtribe Canarininae (Canarina), subtribe Ostrowskiinae (Ostrowskia), subtribe Cyclocodoninae (Cyclocodon), subtribe Echinocodoninae (Echinocodon), and subtribe Cyananthinae (Codonopsis,
    Research Articles
  • De-Yuan Hong, Qiang Wang
    J Syst Evol. 2015, 53(3): 203-209.
    The Campanulaceae s.s. have been proved to be monophyletic, but the subdivision of the family is still controversial among authors. To investigate the intrafamilial structure of the Campanulaceae s.s., four chloroplast DNA fragments, atpB, matK, rbcL, and petD with the petB-petD spacer region, were chosen for molecular phylogenetic analysis, and 90 taxa representing 36 genera of this family were sampled. The result shows that the Campanulaceae s.s. consist of three strongly supported monophyletic clades. This result is highly correlated with the data from palynology and external morphology. Therefore, we propose to establish a new three tribal classification system of Campanulaceae s.s. The Cyanantheae is characterized by colpate or colporate pollen with elongate apertures and a loculicidal capsule which is dehiscent by apical valves, or a berry. The other two tribes have porate pollen with poroid apertures, but the Campanuleae possesses a poricidal capsule which is dehiscent by lateral pores or valves, or a dry indehiscent fruit, whereas the Wahlenbergieae possesses a loculicidal capsule which is dehiscent by apical valves, pores, or opercula. In the Cyanantheae, we recognize 6 subtribes and 10 genera. In addition, keys to tribes of Campanulaceae s.s. and to subtribes and genera of the Cyanantheae are presented.
  • Yun-Juan Zuo, Jun Wen, Jin-Shuang Ma, Shi-Liang Zhou
    J Syst Evol. 2015, 53(3): 210-220.
    The Panax bipinnatifidus species complex (P. bipinnatifidus and its close relatives) in the Sino-Himalayan region has been taxonomically difficult. Evolutionary analyses using amplified fragment length polymorphism (AFLP) markers were carried out on 125 individuals representing 11 populations of the P. bipinnatifidusspecies complex and one population of P. stipuleanatus Tsai & Feng as an outgroup. The populations from the eastern Himalayan region, sampled from Nepal and eastern Tibet, formed two main groups in the neighbor-joining and split network analyses. The Pailong population (Tibet-PL) in eastern Tibet showed a highly distinct AFLP profile and was placed as the most basally branched group in the neighbor-joining tree. The remaining Himalayan populations showed three subgroups: the Nepal-HB and Nepal-HS subgroup, the Nepal HH subgroup, and the Tibet-BY subgroup. The three Himalayan subgroups had very limited gene flow among them and showed subtle morphological differences. The populations in eastern, central, and western China showed clear geographic patterns and can be sorted into several geographical groups. Each major group in the species complex has strong bootstrap support, but relationships among them are poorly resolved, which is consistent with a pattern of evolutionary radiation. The strong geographic grouping, high Nei's population differentiation index, and limited gene flow among populations in different regions support the importance of geographic isolation in the diversification of the P. bipinnatifidus species complex in the Sino-Himalayan region.
  • Xin-Min Tian, Peng Wang, Wen-Bin Hu, Da-Hai Gao, Qiong Li
    J Syst Evol. 2015, 53(3): 221-227.
    Thiamine pyrophosphate (TPP)-dependent enzymes are present in all domains of life, which share a cofactor with TPP. However, a comprehensive analysis of TPP-dependent enzymes from sequenced genomes has not been reported and little is known about the evolutionary dynamics of this gene family in plants. In this study, the evolutionary relationships of the TPP-dependent enzymes were investigated by using a comprehensive genome-wide phylogenetic analysis. A total of 103 plant TPP-dependent enzyme sequences were identified in 16 plant species. Phylogenetic analyses suggest that these plant TPP-dependent genes fell into three major groups, acetolactate synthase, pyruvate dehydrogenase, and 2-hydroxyphytanoyl-CoA lyase. Our results showed fewer TPP-dependent genes in plants than that in other living organisms, with many types of genes lost during evolution possibly because they do not largely influence plant function. Within the plant kingdom, seed plants have more TPP genes compared to non-seed basal plants, which probably imply that seed plants developed more TPP genes to adapt to their environment. The present study provides important information for understanding the evolution and function of the TPP-dependent gene family in plants.
  • AJ Harris, Sue Lutz, Pedro Acevedo, Jun Wen
    J Syst Evol. 2015, 53(3): 228-238.
    In this study, we examined the utility of pollen morphology for resolving questions about the evolutionary history of Billia, which is a poorly known genus of Neotropical trees. Billia has been traditionally circumscribed with two species and treated as sister to Aesculus L. However, the number of species in Billia is uncertain, because the genus exhibits abundant morphological diversity but little discontinuous variation. Therefore, Billia may be monotypic and highly polymorphic, or it may have two species with blurred boundaries due to incipient speciation and/or hybridization. Moreover, one recent molecular phylogenetic study shows Billia nested withinAesculus. Our work sought to address the following questions: (i) Are there discontinuities in the pollen of Billia that may suggest species boundaries? (ii) Does the pollen of Billia show evidence for inter-specific hybridization? (iii) Do the exine morphology and size of pollen in Billia differ from those in Aesculus? Our results from scanning electron microscopy showed that pollen exine morphology is not taxonomically informative in Billia but that there are significant differences in pollen size between red- and white-flowered individuals. Thus, our pollen data support the utility of flower color in Billia for species delimitation. Our assessments of pollen viability do not support hybridization in the genus, but cannot be used to rule it out. Finally, pollen exine morphology may lend some support to an evolutionary origin ofBillia within eastern North American Aesculus. In contrast, data on pollen size suggest that Billia may belong in a topological position outside of Aesculus.
  • Yi-Jun Lu, Chuan Chen, Rui-Hong Wang, Ashley N. Egan, Cheng-Xin Fu
    J Syst Evol. 2015, 53(3): 239-251.
    Chimonanthus praecox (L.) Link is a widely cultivated endemic winter-flowering plant in China that has a long cultivation history. Genetic diversity and genetic structure were compared between wild and cultivated groups to reveal the geographic origin of the cultivated genotypes using chloroplast DNA (cpDNA) sequences and amplified fragment length polymorphism (AFLP) markers. Nine haplotypes were identified using three combined chloroplast fragments. Based on chloroplast data, the wild group showed greater genetic variation and genetic differentiation and a lower measure of gene flow compared to the cultivated group. The AFLP markers also supported this trend. More than 40% of the cpDNA haplotypes were shared between wild and cultivated groups, with shared haplotypes originating from multiple wild populations, suggesting multiple origins of cultivated plants. Moreover, principal coordinate analysis, UPGMA, and structure analysis of AFLP markers revealed that two wild populations clustered with most of the cultivated populations of Ch. praecox, suggesting that most of the cultivated populations mainly originated from these two populations. The combined cpDNA and AFLP results indicated that modern cultivated Ch. praecox experienced multiple events of origin involving two geographic origins, eastern China (Tianmu Mountain) and southwestern China (the border of Hunan–Guangxi–Sichuan–Guizhou).
  • Ke-Nan Liu, San-Ping Xie, Steven R. Manchester, Yun-Feng Wang, Yang Shao, Bin-Ke Li
    J Syst Evol. 2015, 53(3): 252-258.
    The genus Ventilago Gaertn. usually occurs in hot, dry, and low-altitude tropical environments. The fossil record of this genus is meager, so its origin and geographic history are still poorly understood. We describe a fossil winged fruit species—Ventilago lincangensis K. N. Liu & S. P. Xie sp. nov. from the upper Miocene Bangmai Formation of Lincang city, Yunnan Province, China. The fossil conforms to the modern genus Ventilago in architecture of the prominent fruit wing including a prominent midvein, a set of minor longitudinally secondary veins extending the full length of the fruit and reticulate higher order venation. The elliptical fruit body at the base of the wing shows an equatorial rim and has a short pedicel. This is the first report of Ventilago fruits in China, and is significant for the investigation of the origin and evolutionary history of this genus.
  • Xiao-Fang Jin, Zhong-Ming Ye, Qing-Feng Wang, Chun-Feng Yang
    J Syst Evol. 2015, 53(3): 259-265.
    Sensitive stigma has been recognized to facilitate outcrossing. We hypothesized that species with different levels of sensitivity might have corresponding differences in components of their breeding system. In this study, three Mazus species with bilobed stigmas were used to test the hypothesis. We explored stigma behaviors of the species in reaction time, recovery time, permanent closing time, and the minimum pollen load causing permanent closure. We investigated floral traits, pollinator type and behavior, pollination intensity, and natural schedule of pollen deposition on stigma. Moreover, we evaluated the mating system of the species by checking seed set after controlled pollination treatments, namely, natural flowers with open pollination, enclosed flowers without pollination, and enclosed flowers with self and outcross hand pollination. Results indicated that stigma of M. pumilus (N. L. Burman) Steenis was not sensitive, whereas stigmas of M. miquelii Makino and M. stachydifolius (Turcz.) Maxim. closed and reopened quickly in response to pollination. Accordingly, hand pollination treatments revealed that seed set of self-spontaneous pollination in M. pumilus was similar to the other treatments. For M. miquelii, outcross pollen resulted in significantly higher seed set than self-pollen.Mazus stachydifolius was self-incompatible. Additionally, the corresponding characteristics in other components of the breeding system for each species were found. Our study indicated that the sensitivity of bilobed stigma might be linked with floral traits and the mating system in a given species. Sensitive stigma should be regarded as an evolutionary mechanism for enhancement of outcrossing.
  • Edson D. da Silva, Ana M. G. de A. Tozzi, Leonardo D. Meireles
    J Syst Evol. 2015, 53(3): 266-279.
    The Atlantic Forest is one of the most threatened tropical forests in the world. Leguminosae, by its great richness and dominance among arboreal stratum elements, is of major importance in the floristic composition and structure of this forest. We investigated the distribution of legume species on an altitudinal gradient to find out the altitudinal zones with higher richness of species; the altitudinal zones with greater floristic similarity; the possible presence of species that may be exclusive to certain vegetation types and the altitudinal amplitudes of those species, as well as the occurrence of species substitution along the altitudinal gradient. Therefore, thirty one studies conducted in different altitudinal levels between 5° S and 29° S were analyzed. A matrix with 142 tree species distributed in altitudinal zones (every 100 m) from sea level to 2100 m was built. The greatest species richness was observed in the Submontane Forest (50–500 m) with 92 species. The cluster analysis revealed a strong dissimilarity of the 1400–2100 m (Upper Montane) and 0–10 m zones (Restinga Forest). The Submontane and the Montane Forest share the highest number of species (38 ssp.). Forty species are unique to Submontane. Substitution of species was verified. Some species have their preferred habitat located at a specific altitudinal amplitude, as is the case of Inga laurina and I. subnuda (0–10 m), I. lanceifolia and Machaerium scleroxylon (800–1200 m). The Leguminosae, although well adapted to the first colonization and establishment of diverse environment, was poorly represented above 1500 m altitude.