Effects of genes increasing the number of spikelets per panicle,TAW1 and APO1, on yield and yield-related traits in rice

The genes TAWAWA1 (TAW1) and ABERRANT PANICLE ORGANIZATION1 (APO1) increase the number of spikelets per panicle (SN). In the present study, we examined the effects of these genes on morphological traits, yield, and yield-related traits including yield components using the near-isogenic lines (NILs) in the genetic background of a japonica rice variety, Koshihikari – NIL-taw1, NIL-apo1-D3, and NIL-apo1-D4 – in a field experiment. The SN and total number of spikelets per area of the three NILs were larger than those of Koshihikari. However, the yield of the three NILs did not exceed that of Koshihikari due to their low filling ability. Interestingly, our field experiments indicated that TAW1 did not affect the diameter of internodes and the PN, whereas APO1 decreased the PN and increased the diameter of internodes. These results suggest that TAW1 and APO1 differently affect yield-related traits.     

Mass propagation method from the cutting of three dipterocarp species

We developed a vegetative propagation system for mass-producing three dipterocarps species,Shorea selanica Bl.,Shorea leprosula Mig., andShorea platyclados Sloot. This system uses fog evaporative cooling inside a greenhouse to reduce the leaf-to-air vapor pressure deficit (leaf-to-air VPD) inside the propagator, even under high irradiance conditions. This cooling method has no negative influence on medium conditions such as overwetting. A plastic tent propagator combined with this cooling method was used for vegetative propagation experiments. In mass-production experiments, the annual rooting percentages from the cuttings were low in the first 2 years (1997–1998) due to operational problems of the tent propagator (S. selanica, 48–51%;S. leprosula, 56–59%;S. platyclados: 50–63%). A hard cover propagator improved the rooting percentages in the mass-production experiments in 1999 because it made operations easier (S. selanica, 70%;S. leprosula, 77%;S. platyclados, 77%). This system, which uses a combination of fog evaporative cooling and a hard plastic propagator, should be useful for the mass propagation of these dipterocarp planting stocks. This study was carried out under a joint project of the Ministry of Forestry, Indonesia and Komatsu Ltd. The project was supported by Research Association for Reforestation of Tropical Forest (RETROF) organized by Japanese Forestry Agency.     

Structure of xylan from culms of bamboo grass (Sasa senanensis Rehd.)

Xylan prepared from culms of kumaizasa (Sasa senanensis Rehd.), a representative species of bamboo grass, was hydrolyzed with-xylanase ofStreptomyces olivaceoviridis E-86. Four arabinoxylo-oligosaccharides and two glucuronoxylo-oligosaccharides were isolated from the enzymatic hydrolysate of the xylan by chromatography on a charcoal column, a Dowex 1-x8 column, a Toyo-pearl HW-40S column, and a LiChrospher 100 NH₂ column and on preparative paper chromatography. The results of the structural analyses of the saccharides showed that the isolated oligosaccharides had the structures of 3²--l-arabinofuranosyl-xylobiose, 3²--l-arabinofuranosyl-xylotriose, 3²--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylobiose, 3³--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylotriose, 2³--4-O-methyl-d-glucuronosyl-xylotriose, and 2³--d-glucuronosyl-xylotriose. From the structural analysis of the oligosaccharides derived from the xylan, kumaizasa xylan was concluded to be a kind of arabinoglucuronoxylan having not only stubs of singlel-arabinose and singled-glucuronic acid but also stubs of disaccharide units such as-d-xylopyranosyl-(1 2)-l-arabinofuranose.     

Effects of silviculture treatments in a hurricane-damaged forest on carbon storage and emissions in central Hokkaido,Japan

Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm (understory vegetation removal) led to the largest amount of carbon stored (64.7 t·ha-1 C). Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid (L. gmelinii var. japonica × L. kaempferi) plantation (80.3 t·ha-1 C). The plantation of Abies sachalinensis was not successful at accumulating carbon (40.5·ha-1 C). The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.     

Serotonin derivatives, major safflower (Carthamus tinctorius L.) seed antioxidants, inhibit low-density lipoprotein (LDL) oxidation and atherosclerosis in apolipoprotein E-deficient mice

The effects of defatted safflower seed extract and its phenolic constituents, serotonin derivatives, on atherosclerosis were studied. Ethanol-ethyl acetate extract of safflower seeds (SSE) inhibited low-density lipoprotein (LDL) oxidation induced in vitro by an azo-containing free-radical initiator V70 or copper ions. Two serotonin derivatives [N-(p-coumaroyl)serotonin, CS; N-feruloylserotonin, FS] and their glucosides were identified as the major phenolic constituents of the extract. The study with chemically synthesized materials revealed that a majority of the antioxidative activity of SSE was attributable to the aglycones of these two serotonin derivatives. Orally administered CS and FS suppressed CuSO(4)-induced plasma oxidation ex vivo. Long-term (15 week) dietary supplementation of SSE (1.0 wt %/wt) and synthetic serotonin derivatives (0.2-0.4%) significantly reduced the atherosclerotic lesion area in the aortic sinus of apolipoprotein E-deficient mice (29.2-79.7% reduction). The plasma level of both lipid peroxides and anti-oxidized LDL autoantibody titers decreased concomitantly with the reduction of lesion formation. Serotonin derivatives were detected as both intact and conjugated metabolites in the plasma of C57BL/6J mice fed on 1.0% SSE diet. These findings demonstrate that serotonin derivatives of SSE are absorbed into circulation and attenuate atherosclerotic lesion development possibly because of the inhibition of oxidized LDL formation through their strong antioxidative activity.     

Growth and maturation of Pacific saury Cololabis saira under laboratory conditions

This study details the growth and maturation processes of Pacific saury Cololabis saira from eggs to first spawning under laboratory conditions. They were reared at 20°C, and fed almost to satiation every day. There was no significant difference in the knob length (KnL) between males and females, and so data for both sexes were combined in the following Gompertz growth formula: KnL _t  = 277.1 exp[?exp(?0.015 (t ? 83.8))]. The first spawning was observed 243 days after hatching (DAH). At the beginning of spawning, when the mean KnL was about 250 mm, only several hundred eggs were spawned at most. The spawning continued, and the number of spawned eggs increased notably after 260 DAH. Correlation and stepwise multiple regression analysis of the gonad somatic index (GSI) of Pacific saury versus KnL, CF, and DAH revealed that only DAH (R = 0.88 and 0.72 for males and females, respectively) was significantly correlated with GSI of Pacific saury (P < 0.001). This result suggests that DAH is one of the most influential factors for maturation in this species.     

Analysis of mesh breaking loads in cotton gill nets: Possible solution to ghost fishing

ABSTRACT:   A small number of fishers in Chiba Prefecture of eastern Japan use cotton gill nets to catch Japanese spiny lobster Panulirus japonicus. To examine the advantages of cotton gill nets, we analyzed changes in mesh breaking load of a new cotton gill net used in a fishing operation. A new cotton gill net was also soaked in a seawater tank to simulate ghost fishing conditions. The average mesh breaking load of new cotton mesh was 50.3 N. This value decreased to 19.0 N after 38 days (∼912 h), and after 82 days (∼1968 h) the mesh could be easily torn (breaking load 0.07 N). Under fishing conditions, the cumulative soak time was only 744.4 h over 19 months. The average breaking load at the end of this period was 43.1 N, a strength 86% that of the presoaked mesh. The mesh breaking load of a cotton gill net continuously soaked for 744.4 h was 26.1 N, as estimated from tank experiment data. Thus, a cotton gill net maintains reasonable strength under typical use conditions, but will degrade if lost at sea.     

Field trap test for bioassay of synthetic (1<Emphasis Type="Italic">S</Emphasis>,4<Emphasis Type="Italic">R</Emphasis>)-4-isopropyl-1-methyl-2-cyclohexen-1-ol as an aggregation pheromone of <Emphasis Type="Italic">Platypus quercivorus</Emphasis> (Coleoptera: Platipodidae)

An ambrosia beetle, Platypus quercivorus, is a vector of Japanese oak wilt, which causes massive mortality of oak trees in Japan. Previous studies have identified (1S,4R)-4-isopropyl-1-methyl-2-cyclohexen-1-ol ((−)-IMCH) as the major component of the aggregation pheromone of P. quercivorus. We tested the ability of synthetic (−)-IMCH to attract P. quercivorus adults. The synthetic compound attracted 14.4 times as many P. quercivorus, of both sexes, as control traps. Control and (−)-IMCH-baited traps both captured 3.32 times as many males as females, probably because of the nature of Lindgren funnel traps and of male-biased emergence sex ratio early in the season of adult flights. (−)-IMCH was proved to be a major component of the aggregation pheromone of P. quercivorus.     

Swimming depths of the giant jellyfish <Emphasis Type="Italic">Nemopilema nomurai</Emphasis> investigated using pop-up archival transmitting tags and ultrasonic pingers

The swimming depths of 12 individual Nemopilema nomurai with bell diameters of 0.8–1.6 m were investigated using pop-up archival transmitting tags and ultrasonic pingers, and the validity of the research method was evaluated. The N. nomurai studied frequently showed vertical movement, with the swimming depth ranging from 0 to 176 m, The mean swimming depths of most individuals were less than 40 m. The swimming depths of N. nomurai in the northern Japan Sea in the winter were mostly deeper than those of this species in the southern Japan Sea in the autumn. This result suggests that the range of the depths almost depends on the vertical structure of the ocean. Swimming depths during the nighttime were significantly deeper than those during the daytime. More specifically, during the daytime, the swimming depths in the afternoon tended to be shallower than those in the morning, while during the nighttime, the swimming depths after midnight were deeper than those before midnight.