Search

Byline: Kyoko Aoki (1), Takeshi Suzuki (2), Noriaki Murakami (1) Keywords: Chloroplast DNA; Evergreen broad-leaved forest; Intraspecific variation; Lucidophyllous forest; Phylogeography Abstract: For the purpose of phylogeographic study of lucidophyllous (evergreen broad-leaved) forests in Japan, we surveyed intraspecific chloroplast DNA (cpDNA) variation in 41 component species of such forests. Intraspecific cpDNA variations were detected in 14 species. In 15 species and one species group, 16 non-coding cpDNA regions were examined to find intraspecific sequence variation. The extent of variation in these regions was compared. The largest amount of intraspecific variation was detected in the rps16 region. A relatively large amount of intraspecific variation was detected in the petD-rpoA, rpl16, and trnL-F regions. It is suggested that these regions of cpDNA would be useful for detecting intraspecific variation in plant species, and could provide valuable information for various research purposes. Author Affiliation: (1) Department of Botany, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan (2) Division of Biological Resources, Museum of Nature and Human Activities, Sanda, Japan Article History: Received Date: 03/02/2003 Accepted Date: 21/04/2003 Online Date: 19/06/2003

Byline: Yoshio Ino (1), Tomoyuki Maekawa (1), Tomohiro Shibayama (1), Yoshiaki Sakamaki (1) Keywords: Adaptation to heavy snow; Carbohydrate; Evergreen shrub; Matter economy; Respiration; Strategy for wintering Abstract: Plant adaptation to an environment subject to heavy snowfalls was investigated in four species of evergreen shrubs growing in a Fagus crenata forest in an area of Honshu on the Sea of Japan. These shrubs stored carbohydrates in some organs before the snowy season and were covered with snow for 4--5 months. Aucuba japonica var. borealis, Camellia rusticana, and Ilex crenata var. paludosa maintained a reserve of carbohydrates during the snowy season. In Daphniphyllum macropodum var. humile, the reserve of carbohydrates decreased during winter. The respiration rates in the first three species decreased from autumn to winter, whereas the decrease in D. macropodum was slight. It was found that the first three species could use reserve carbohydrates for the growth of new shoots after the thaw, whereas in the last species the growth of new shoots depends on high photosynthetic activity in late spring. Our findings suggest some types of matter economy in evergreen shrubs for wintering in an environment of heavy snow. Author Affiliation: (1) Department of Biology, School of Education, Waseda University, Tokyo 169-8050, Japan Article History: Received Date: 26/09/2002 Accepted Date: 31/03/2003 Online Date: 15/05/2003

Byline: Nozomi Isogai (1), Yasuo Yamamura (1), Shigeru Mariko (2), Takashi Nakano (3) Keywords: Evergreenness; Matter production; Pyrola; Seasonal growth; Subalpine Abstract: The seasonal pattern of growth and matter production of Pyrola incarnata, an evergreen herb on the forest floor in subalpine deciduous forests, was analyzed to understand the ecological significance of evergreenness in a subalpine climate with a short growing season and low temperature. Net production was highest under favorable light conditions in spring after the disappearance of snow cover, and 68% of the annual net production was attained before the canopy tree foliage had fully expanded. Most of the photosynthetic production in this period was carried out with over-wintered leaves. This appears to be an advantage of evergreenness. New leaves and inflorescences had developed in the period. Positive net production was maintained under deteriorating light conditions during summer, when 32% of the annual net production occurred. This production was used mainly for growth of fruits and underground organs. The net production of P. incarnata during summer was much higher than that of a related species that inhabits warm-temperate regions, because of its higher photosynthetic activity rather than its lower respiratory losses. The storage of dry matter in leaves and underground organs was not conspicuous. Unlike the warm-temperate species and another subalpine species that inhabits higher altitudes, P. incarnata is not strongly dependent on its reserve matter for the development of new organs. Author Affiliation: (1) Department of Environmental Sciences, Faculty of Science, Ibaraki University, 2-1-1 Bunkyo, Mito 310-8512, Japan (2) Institute of Biological Sciences, University of Tsukuba, Tsukuba, Japan (3) Yamanashi Institute of Environmental Sciences, Fujiyoshida, Japan Article History: Received Date: 04/03/2002 Accepted Date: 10/02/2003 Online Date: 24/04/2003

Byline: Wu (1), Juei-Er (1), Shong Huang (1), Jenn-Che Wang (1), Wu-Fu Tong (1) Keywords: Keywords: Allozymes, Genetic diversity, Population differentiation, Trochodendron aralioides Abstract: Siebold &amp Zucc., a primitive angiosperm that is insect-pollinated, has wind-dispersed seeds and grows only in eastern Asia. Nineteen populations were analyzed, including 16 from Taiwan, two from the main islands of Japan and one from Iriomote Island in the Ryukyu Islands. Genetic variability (0.133) at the species level was more similar to that of a narrow geographic species than an endemic species. Based on genotype frequencies, mating within populations was non-random (F .sub.I .sub.s=0.065) and there was significant genetic differentiation (F .sub.ST=0.164) among populations. Genetic diversity was largely within, rather than among, populations (H .sub.s=0.132, 85.14%). Bisexual flowers of T. aralioides exhibit synchronized dimorphism. The protogynous and protandrous morphs are self-incompatible, which probably promotes outcrossing and contributes to the high levels of heterozygosity within populations. Using a maximum likelihood tree, populations of T. aralioides were separated into two distinct clusters: Japan and Taiwan/ Iriomote Island. Populations of T. aralioides on Iriomote Island and in northern Taiwan exhibited a high degree of genetic similarity. The isolation-by-distance model does not fit populations in Taiwan, but suitably describes the relationship between populations of T. aralioides in Japan and Taiwan. Author Affiliation: (1) Department of Biology, National Taiwan Normal University, Taipei, 11650 Taiwan, Republic of China, CN Article note: Received 28 April 2000/ Accepted in revised form 13 December 2000