Seasonal changes of azimuthal,radial, and tree-to-tree variations in sap flux affect stand transpiration estimates in a <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> forest,central Taiwan

Stand transpiration (E) estimated using the sap flux methods is affected by the azimuthal, radial, and tree-to-tree variations of sap flux. Although several studies have examined the relative importance of the three variations in estimating E, the seasonality of the three variations remains unknown. In the current study, we attempted to clarify whether the relative importance of these three variations could show seasonal changes. Using sap flux data measured in a subtropical cloud forest from August 2010 to July 2011, we calculated the differences resulting from omitting the three variations in estimating E. The effects of the three variations in estimating E showed seasonality. The azimuthal and tree-to-tree variations were more pronounced during winter, whereas the radial variation was more pronounced during summer. However, the effect of tree-to-tree variation was consistently much larger than the other two variations throughout the study period. The tree-to-tree variation is more important in estimating E monthly, seasonally and annually than both the azimuthal and radial variations, although all three variations have shown seasonality. In addition, the sensor allocation for summer would be acceptable for the practical estimation of E if aiming at the long time scale.     

Effects of wet–dry cycling on the mechanical properties of Arundo donax L. used for the vibrating reed in woodwind instruments

Wood Science and Technology - The effects of wet–dry and moist–dry cycling on the mechanical properties of reed (Arundo donax L.) were investigated. Because water-soluble extractives...     

Kid depletion in mouse oocytes associated with multinucleated blastomere formation and inferior embryo development

This study investigated the knockdown (KD) of Kid on maturation developmental competence and multinucleation of mouse germinal vesicle (GV) oocytes after parthenogenetic activation. Data revealed that Kid messenger RNA (mRNA) was expressed in GV and MII stage oocyte and 1‐ and 2‐cell embryos. Additionally, Kid mRNA expression in the Kid KD group decreased by nearly 46% compared to the control small interfering RNA (siRNA) groups. The rate of multinucleated embryos in the Kid KD group (52.4%) was significantly higher (P < 0.05) than the control siRNA group (4.7%). Finally, the developmental rates were significantly lower in the Kid siRNA group at > 4‐cell stage (28.6% vs. 53.5%) and the blastocyst stage (2.4% vs. 23.3%) compared to the control siRNA groups. Suppression of Kid using siRNA caused multinucleation in early embryos with high frequency and it may increase 2‐ to 4‐cell arrested embryos and reduce the developmental competence to blastocyst.     

Rainfall interception in a moso bamboo (Phyllostachys pubescens) forest

In recent years, moso bamboo (Phyllostachys pubescens) forest areas in Japan have rapidly expanded, and bamboo is now invading nearby natural or plantation forests. To date, only one study has examined the rainfall interception of a moso bamboo forest. In that study, it was reported that the interception ratio (interception/rainfall) of the bamboo forest did not exceed the interception ratios of other natural and plantation forests (n = 4) in Japan. To expand the current state of knowledge about rainfall interception of bamboo forests, we measured throughfall and stemflow at another bamboo forest site. Annual rainfall (Rf), throughfall (Tf), and stemflow (Sf) during the measurement period were 2,105, 1,556, and 322 mm, respectively. Annual rainfall interception at the plot (I) was 228 mm. Tf/Rf, Sf/Rf, and I/Rf were 73.9, 15.3, 10.8%, respectively. I/Rf was less than 20% throughout the year except in October, the month with lowest rainfall. We also summarized rainfall interception data from 19 other natural and plantation forests. The I/Rf value of our site did not exceed the I/Rf values of these natural and plantation forests (n = 19). Our data will be useful for assessing changes in water resources that result from replacement of natural or plantation forests by bamboo forests.     

SSR-tagged breeding scheme for allogamous crops: a trial in bunching onion (<Emphasis Type="Italic">Allium fistulosum</Emphasis>)

In several autogamous and vegetatively propagated crops, DNA markers have been used for cultivar identification. However, allogamous crops such as bunching onion (Allium fistulosum L.) are recalcitrant to marker-aided cultivar identification, as well as hybrid seed purity tests, due to the high degree of genetic heterogeneity within each cultivar. To aid cultivar identification and ensure its accuracy in bunching onion, we proposed the “SSR-tagged breeding” scheme in our previous study. The feasibility of this scheme was investigated here using a landrace of bunching onion with two populations tagged with two or four selected SSR markers. Compared with a control population, no significant differences were detected in the agronomic traits of the SSR-tagged populations. The targeted SSR loci were genetically uniform within each population whereas other loci maintained high heterogeneity. These results demonstrate that the SSR-tagged breeding scheme, even with a very small number of markers, is efficient for the identification of newly bred cultivars, and consequently for F₁ purity tests, in allogamous crops in which inbreeding depression is as severe as in bunching onion.     

Genetic identification and morphology of naturally spawned eggs of the Japanese eel Anguilla japonica collected in the western North Pacific

Eggs of the Japanese eel Anguilla japonica collected in the western North Pacific were identified by onboard species-specific polymerase chain reaction (PCR) and DNA nucleotide sequencing after the cruise. Fish eggs of various species were collected by large plankton net tows at 12 stations along the southern part of the West Mariana Ridge on 19–25 May 2009. A total of 43 fish eggs were distinguished morphologically as possibly being of A. japonica. Thirty-one of those were analyzed by PCR, which included 15 eggs collected at 12°50–55′N, 141°15–20′E (in 5 tows) that showed positive results. The 16S ribosomal RNA (rRNA) gene sequences of eggs determined after the cruise indicated that 31 A. japonica eggs had been collected. The remaining eggs were of mesopelagic eel species (Serrivomeridae and Derichthyidae), or unidentified species. The morphological characteristics of the A. japonica eggs were consistent with those of artificially spawned eggs, except they had a slightly larger diameter. The egg diameter range did not overlap with those of mesopelagic eels of the Serrivomeridae, which often spawn in the same area as A. japonica. These results suggest that egg diameter and embryo shape can be used to morphologically identify naturally spawned A. japonica eggs.     

Structural Characteristics,Properties, and In Vitro Digestibility of Rice

Using rice samples derived from normal rice cultivars and endosperm starch mutant, we investigated key factors contributing to the enzyme digestibility of steamed rice grains. The chemical composition of polished rice grains, structural features of endosperm starch, and enzyme digestibility of steamed rice grains were examined. The protein content of polished rice grains was 4.6–9.1%, amylose content was 4–27%, the DP_n of purified amylose was 900–1,600, the amylopectin short/long chain ratio was 1.2–5.9, and the enzyme digestibilities of steamed polished rice grains were 0.9–12.6 °Brix. Amylose content and RVA parameters (viscosity, breakdown, and setback) correlated significantly with enzyme digestibility of steamed rice grains. Multiple regression formulas were constructed to predict digestibility of steamed rice grain as a function of the molecular characteristics of the starch. When both amylose content and the short/long chain amylopectin ratio were used as predictor variables, they accounted for >80% of the observed variance in digestibility of steamed rice grains. Multiple regression revealed that the more digestible rice samples had starch with a lower amylose content and more short‐chain amylopectin. Reassociation of amylose‐lipid complex and recrystallization of amylopectin in the stored steamed rice grains was monitored by differential scanning calorimetry (DSC), and the observed retrogradation properties were related to the structural characteristics of starch and to the enzyme digestibility of steamed rice grains.     

Effect of blue and red LED light irradiation on β-cryptoxanthin accumulation in the flavedo of citrus fruits

β-Cryptoxanthin (β-cry), an antioxidant abundant in citrus fruits, plays an important role in the prevention and treatment of certain diseases, especially cancers. In the present study, to increase the content of β-cry in citrus flavedo, the effects of blue (470 nm) and red (660 nm) light-emitting diode (LED) lights on the accumulation of carotenoids and expression of genes related to carotenoid biosynthesis were investigated in the flavedo of Satsuma mandarin. The results showed that accumulation of β-cry was induced by red light, while it was not affected by blue light. The accumulation of β-cry under red light was attributed to simultaneous increases in the expression of CitPSY, CitPDS, CitZDS, CitLCYb1, CitLCYb2, CitHYb, and CitZEP. The results presented herein might provide new strategies to enhance the commercial and nutritional value of citrus fruits.     

Detection of novel kobu-like viruses in Japanese black cattle in Japan

During surveillance for bovine diarrhea of unknown causes in Japanese black cattle in Kagoshima Prefecture, Japan, we found two types of novel kobu-like viruses in fecal samples of calves. Sequence analyses revealed that they had L protein and 2A protein with H-box/NC sequence motif, which are present in kobuviruses. Phylogenetic analysis revealed that they were related to kobuviruses; however, they clustered apart from other kobuviruses. In the prevalence study of two types of novel kobu-like viruses, 16.9% and 10.4% prevalence of these viruses were observed in the feces of diarrheal calves in this area.