Anatomically preserved seeds of Nuphar (Nymphaeaceae) from the Early Eocene of Wutu, Shandong Province, China

Well-preserved seeds from the early Eocene of Wutu, Shandong, China are assigned to the genus Nuphar (Nymphaeaceae) based on morphology and anatomy. The seeds of Nuphar wutuensis sp. nov. are ellipsoidal to ovoid, 4-5 mm long with a clearly visible raphe ridge, and a truncate apex capped by a circular operculum ca. 1 mm in diameter bearing a central micropylar protrusion. These features, along with the testa composed of a uniseriate outer layer of equiaxial pentagonal to hexagonal surface cells and a middle layer 4-6 cells thick composed of thick-walled, periclinally elongate sclereids, correspond to the morphology and anatomy of extant Nuphar and distinguish this fossil species from all other extant and extinct genera of Nymphaeales. These seeds provide the oldest record for the genus in Asia and are supplemented by a similar well-preserved specimen from the Paleocene of North Dakota, USA. These data, together with the prior recognition of Brasenia (Cabombaceae) in the middle Eocene, indicate that the families Nymphaeaceae and Cabombaceae had differentiated by the early Tertiary.     

Seed morphology of modern and fossil Ampelocissus (Vitaceae) and implications for phytogeography

Seeds are useful in distinguishing among extant genera of Vitaceae and provide a good basis for interpretation of fossil remains in reconstructing the evolutionary and phytogeographic history of this putatively basal Rosid family. Seeds of Ampelocissus s.l. including Pterisanthes and Nothocissus are distinguished from those of all other vitaceous genera by long, parallel ventral infolds and a centrally positioned oval chalazal scar. Principal component analysis facilitates recognition of four Ampelocissus s.l. seed morphotypes differentiated by dorsiventral thickness, width of ventral infolds, chalazal depth, and degree of dorsal surface rugosity. While these intergrade, their end-member morphologies are distinctive and coincide well with inflorescence morphology, extant geographic distribution, and ecology. Seven fossil morphospecies are recognized. Ampelocissus parvisemina sp. n. (Paleocene of North Dakota; Eocene of Oregon) and A. auriforma Manchester (Eocene of Oregon) resemble extant Central American species; A. bravoi Berry (Eocene of Peru) is similar to one group of Old World extant species; and A. parachandleri sp. n. (Eocene of Oregon) and the three European fossil species A. chandleri (Kirchheimer) comb. n., A. lobatum (Chandler) comb. n., and A. wildei sp. n. (Eocene to Miocene) resemble another group of extant Old World Ampelocissus. All these fossils occur outside the present geographic range of the genus, reflecting warmer climates and former intercontinental links.     

Pseudocayratia,a new genus of Vitaceae from China and Japan with two new species and three new combinations

Recent integrative systematic studies of Vitaceae support the recognition of a new genus Pseudocayratia J.Wen, L.M.Lu & Z.D.Chen. The genus consists of five species from China and Japan. We herein describe the following two new species: Pseudocayratia speciosa J.Wen & L.M.Lu, and P. pengiana Hsu & J.Wen, and make three new combinations: Pseudocayratia dichromocarpa (H.Lév.) J.Wen & Z.D.Chen, P. oligocarpa (H.Lév. & Van.) J.Wen & L.M.Lu, and P. yoshimurae (Makino) J.Wen & V.C.Dang. Phylogenetic analyses based on five chloroplast loci strongly support Pseudocayratia as sister to Tetrastigma. Morphologically, species of the genus have stigmas enlarged (but not 4‐lobed), pedicels at fruiting stage enlarged and fleshy, seeds with a crustaceous thin testa, circular cup‐like ventral infolds, linear chalaza extending ca. 2/3 to 3/4 of the seed length (from apex to base), lateral margin with thin edges, and T‐shaped endosperm in cross‐section. The genus is distributed in eastern Asia (China and Japan). The taxonomic novelties we report in this study at both the generic and species levels highlight the importance of collections‐based research in today's integrative systematics.     

A rapid PCR-aided selection of a rice line containing the Rf-1 gene which is involved in restoration of the cytoplasmic male sterility

Cytoplasmic male sterility (CMS) is widely known in higher plants, the mechanism of which is believed to involve incompatibility between nuclei and cytoplasms. In rice lines with the CMS trait, fertility is restored by the aid of a nuclear-encoded gene, Rf-1, whose locus has been determined in chromosome 10. We found a particular PCR-amplified fragment, designated fL601, that specifically amplified using the DNAs from Rf-1 lines tested as templates. RFLP mapping of the fL601 locus revealed that there are two loci for the fL601, and that both are tightly linked to the Rf-1 locus. Progeny analysis also showed high frequency of their co-segregation. Southern analysis of the genomic DNA demonstrated that the Rf-1 lines shared a unique sequence in the fL601 region. These results enabled us to construct a system for specific detection of the corresponding regions. Utilizing this detection system, we established a simple PCR-mediated selection method for the Rf-1 lines, which may facilitate the breeding for hybrid rice.     

Epidemiological and Ecological Studies of Japanese Encephalitis in Okinawa,Subtropical Area in Japan. II. Prevalence of Japanese Encephalitis Antibody in Residents in Okinawa,Miyako and Ishigaki Islands

During 1989 to 1990, human sera were collected by age groups in Okinawa (the northern, central and southern areas), Miyako and Ishigaki islands and examined for the neutralization (N) antibodies to two strains, Nakayama (vaccine strain) and C307 (Okinawan strain), of Japanese encephalitis (JE) virus. In Okinawa island, the N antibody positive rate to C307 was higher than that to Nakayama, while in Miyako and Ishigaki islands, the positive rate to Nakayama was higher than that to C307, suggesting that JE virus transmission rate was higher in Okinawa than in Miyako and Ishigaki islands. In Okinawa Prefecture, JE vaccine had not been administered to most of residents over 31 years of age at the time of serum collection. In residents over 31 years old, the positive rate to C307 was highest in the north of Okinawa (83.3%) and was lowest in Miyako (26.3%), with the second lowest in Ishigaki (33.3%). The distribution of N antibody titers to C307 gave hyperbolic patterns in the 0–5 age groups in Miyako and Ishigaki, and also in the 31–40, 41–50 age groups in Miyako and the 41–50 age group in Ishigaki, suggesting low rates of natural infection in these 4–5 decades in both islands. In residents of ages subjected to JE vaccine, a characteristic pattern was obtained, in which the curves to Nakayama shifted to higher titers than those to C307, suggesting that the first antigenic stimulation was caused by vaccine, not by natural infection of JE virus.