Polyscias

Abstract: Chromosome numbers of 45 accessions representing 16 genera and 37 species of Araliaceae are herein reported, of which 30 species and seven genera (Apiopetalum, Arthrophyllum, Delarbrea, Merrilliopanax, Metapanax, Myodocarpus, and Pseudosciadium) are recorded for the first time. The evolution of this character is also examined in light of recent hypotheses of phylogenetic relationships. Chromosome numbers in the family are relatively uniform, generally with 2n = 24 or 48. However, the genus Hedera exhibits extreme variability, with a polyploid series ranging from 2n = 48 to 192. The basic number of Araliaceae is inferred to be x = 12, although x = 6 cannot be ruled out. The "Asian palmate" clade, the largest of the three major clades of core Araliaceae, is primarily characterized by polyploidy, although several genera have sometimes been regarded as evolutionarily "primitive". By contrast, Aralia, Panax, and Polyscias (representing other major clades within the family) include species with both diploids and tetraploids. Four genera recently segregated from core Araliaceae (Apiopetalum, Delarbrea, Myodocarpus, and Pseudosciadium) are reported as n = 12. The formerly apiaceous Hydrocotyle (now placed in Araliaceae) is best interpreted as x = 12, although some aneuploid species may exist with x = 9. Hydrocotyle also exhibits extensive variation in ploidal level. Within Araliaceae, chromosomal variation is largely related to ploidal level, with relatively few cases of aneuploidy, such as those documented in Panax ginseng and Hydrocotyle. The available data are largely consistent with the hypothesis that the basic chromosome number of Apiales is x = 6.

Abstract: francaisPolyscias bernardiana Lowry & Callm., une nouvelle espece facilement reconnaissable du centre-est de Madagascar, incluant le site minier d’Ambatovy et plusieurs zones protegees, est decrite en l’honneur de Luciano Bernardi (1920–2001), un explorateur-naturaliste du 20e siecle qui a plus que tout autre botaniste contribue a notre connaissance de la famille des Araliaceae de l’ocean Indien. Cette nouvelle espece ressemble a Polyscias duplicata (Thouars ex Baill.) Lowry & G.M. Plunkett de Madagascar et des iles Comores par son port arborescent monocaule couronne par un mouchet terminal de grandes feuilles entourant une inflorescence globuleuse, et par ses fleurs et ses fruits munis de carpelles et de styles au nombre de 8–10(–12), mais en differe par un pedicelle articule (vs non articule chez P. duplicata) et depourvu de folioles auxiliaires (par rapport a une deuxieme foliole souvent inseree a l’aisselle des folioles principales de P. duplicata). Polyscias bernardiana est illustre par des dessins au trait et des photos en couleur, et une evaluation du risque d’extinction est fournie sur la base des criteres de la Liste rouge de l’UICN, qui indique un etat de conservation de «Preoccupation mineure». EnglishPolyscias bernardiana Lowry & Callm., an easily recognized new species from east-central Madagascar, including the Ambatovy mine site and several protected areas, is described in honor of Luciano Bernardi (1920–2001), a 20th century explorer-naturalist who has contributed more to our knowledge of Indian Ocean Araliaceae than any other botanist. This new species most closely resembles Polyscias duplicata (Thouars ex Baill.) Lowry & G.M. Plunkett from Madagascar and the Comoro Islands in forming monocaulous trees with a terminal cluster of large leaves surrounding a globose inflorescence, and in having flowers and fruits with 8–10(–12) carpels and styles, but differs in having an articulated pedicel (vs. unarticulated in P. duplicata) and lacking auxiliary leaflets (vs. a second leaflet often inserted in the axil of the main leaflets in P. duplicata). Polyscias bernardiana is illustrated by line drawings and color photos, and a risk of extinction assessment is provided based on the IUCN Red List criteria, which indicates a conservation status of “Least Concern”.

Abstract: Species of Lasiodiplodia are important pathogens of a wide variety of plants covering a wide geographical distribution. These fungi can be associated with different symptoms such as stem cankers, shoot blights, fruit rots, dieback and gummosis. Diseases caused by Lasiodiplodia were surveyed on Eucalyptus urophylla 9 grandis, Polyscias balfouriana and Bougainvillea spectabilis in a nursery in southern China. Based on morphology characteristics and phylogenetic analyses of ITS rDNA sequences and translation elongation factor 1-alpha (TEF-1a) gene regions, four species of Lasiodiplodia were identified. Lasiodiplodia theobromae was identified from E. urophylla 9 grandis, P. balfouriana and B. spectabilis. L. hormozganensis, L. iraniensis and L. pseudotheobromae were identified from B. spectabilis. To our knowledge, with the exception of L. theobromae on E. urophylla 9 grandis, this study represents the first report of these fungi on the host plants. Pathogenicity tests showed that all Lasiodiplodia spp. obtained in this study are virulent to E. urophylla 9 grandis and B. spectabilis, and L. theobromae was virulent to P. balfouriana.