Applicability of Aegilops tauschii drought tolerance traits to breeding of hexaploid wheat

Few genes are available to develop drought-tolerant bread wheat (Triticum aestivum L.) cultivars. One way to enhance bread wheat’s genetic diversity would be to take advantage of the diversity of wild species by creating synthetic hexaploid wheat (SW) with the genomic constitution of bread wheat. In this study, we compared the expression of traits encoded at different ploidy levels and evaluated the applicability of Aegilops tauschii drought-related traits using 33 Ae. tauschii accessions along with their corresponding SW lines under well-watered and drought conditions. We found wide variation in Ae. tauschii, and even wider variation in the SW lines. Some SW lines were more drought-tolerant than the standard cultivar Cham 6. Aegilops tauschii from some regions gave better performing SW lines. The traits of Ae. tauschii were not significantly correlated with their corresponding SW lines, indicating that the traits expressed in wild diploid relatives of wheat may not predict the traits that will be expressed in SW lines derived from them. We suggest that, regardless of the adaptability and performance of the Ae. tauschii under drought, production of SW could probably result in genotypes with enhanced trait expression due to gene interactions, and that the traits of the synthetic should be evaluated in hexaploid level.     

Relationships of culm surface area to other culm dimensions for bamboo, Phyllostachys pubescens

We determine the relationships of culm surface area to other culm dimensions for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houzeau de Lehaie. A total number of 150 sample culms were collected from a stand of P. pubescens in Mt. Toshima, Kumamoto Prefecture, western Japan. The culm surface area for each sample was calculated, and then the relationships of the culm surface area to basal area and product of diameter at breast height (dbh) and culm height were analyzed. The relationship between culm surface area and basal area could be described successfully by the power equation, whereas there was a linear relationship of culm surface area to product of dbh and height. Although the regression equations determined here would be useful in estimating culm surface area of P. pubescens, it is necessary to select an appropriate equation depending on the purpose and available time and labor.     

Evaluation of combustion properties of wood pellets using a cone calorimeter

In this study, the combustion properties of wood pellets were evaluated using a cone calorimeter, which is usually used to verify the fireproof performance of architectural materials. In contrast to the conventional methods including combustion calorimetry and thermogravimetric analysis, a cone calorimeter can estimate various combustion parameters, e.g., changes of heat release rate (HRR), weight decrease during burning process, ignition time, and flame-out and burn-out time as well as combustion heat, in a single experimental run with no pretreatment for sample size reduction. The following results were obtained by the combustion test of Japanese cedar (Cryptomeria japonica) and larch (Larix kaempferi) wood pellets having various volume densities. Ignition time of wood pellet became slower with increasing volume density of the pellets. However, burn-out time was not clearly correlated to volume density. The heat release values measured by cone calorimeter could be comparable to those from the conventional combustion calorimeters, and flaming heat values of the bark pellets were always lower in comparison with pellets made of xylem, although total heat release was almost the same.     

QTL analysis of photoperiod sensitivity in common buckwheat by using markers for expressed sequence tags and photoperiod-sensitivity candidate genes

Photoperiod sensitivity is an important trait related to crop adaptation and ecological breeding in common buckwheat (Fagopyrum esculentum Moench). Although photoperiod sensitivity in this species is thought to be controlled by quantitative trait loci (QTLs), no genes or regions related to photoperiod sensitivity had been identified until now. Here, we identified QTLs controlling photoperiod sensitivity by QTL analysis in a segregating F₄ population (n = 100) derived from a cross of two autogamous lines, 02AL113(Kyukei SC2)LH.self and C0408-0 RP. The F₄ progenies were genotyped with three markers for photoperiod-sensitivity candidate genes, which were identified based on homology to photoperiod-sensitivity genes in Arabidopsis and 76 expressed sequence tag markers. Among the three photoperiod-sensitivity candidate genes (FeCCA1, FeELF3 and FeCOL3) identified in common buckwheat, FeELF3 was associated with photoperiod sensitivity. Two EST regions, Fest_L0606_4 and Fest_L0337_6, were associated with photoperiod sensitivity and explained 20.0% and 14.2% of the phenotypic variation, respectively. For both EST regions, the allele from 02AL113(Kyukei SC2)LH.self led to early flowering. An epistatic interaction was also confirmed between Fest_L0606_4 and Fest_L0337_6. These results demonstrate that photoperiod sensitivity in common buckwheat is controlled by a pathway consisting of photoperiod-sensitivity candidate genes as well as multiple gene action.     

Effects of light and microsite conditions on tree size of 6-year-old Cryptomeria japonica planted in a group selection opening

We examined the extent to which direct and indirect measures of light and microsite conditions could explain variation in tree height and diameter at the base of 6-year-old Cryptomeria japonica trees planted in a group selection opening of about 0.32 ha on a steep slope at Shiiba, Miyazaki Prefecture, southern Japan. We first used the gap light index (GLI) and soil thickness (ST) as directly measured indices. For an indirect measure of light, we used a between-cohort competition index (BCI) estimated from the position and total height of residual trees. For indirect measures of microsite, we examined topographic indices (slope, plan and profile curvature, average slope gradient, and relative elevation) derived from digital elevation models (DEMs) with different resolutions ranging from 2 to 10 m. The multiple linear regression using GLI and ST explained about 45% of variation in tree size, while simple regression using only GLI explained about 35%. The contribution of ST was about half of GLI. The multiple regressions using BCI and the topographic indices did not explain any more variation than using BCI alone (R ² of about 0.26). We conclude that microsite conditions with shallower soil and steeper slope have negative effects on tree growth in group selection openings, although the relative importance is smaller than light conditions. More comprehensive studies considering several openings with more heterogeneous topography including different species are needed to generalize our growth prediction using the indirect measures, which are useful for practical forest management.     

Effects of sika deer (Cervus nippon) and dwarf bamboo (Sasamorpha borealis) on seedling emergence and survival in cool-temperate mixed forests in the Kyushu Mountains

Effects of sika deer (Cervus nippon) and dwarf bamboo (“sasa;” Sasamorpha borealis) on seedling emergence and survival were investigated in cool-temperate mixed forests in the Kyushu mountain range, Japan. We compared the effects of sika deer between two sites with different sika deer densities. One site (no-sasa forest) has sparse cover of S. borealis and a high density of sika deer, and the other site (sasa forest) has dense cover of S. borealis with a low density of sika deer. In the no-sasa forest, more seedlings emerged and the survival rate of the seedlings was higher compared with the sasa forest. Compared with the sasa forest, the canopy in the no-sasa forest was more open, the organic layer was shallower and drier, the mean daily soil temperature was higher, and soil temperature fluctuated more widely. Those environmental parameters did not differ between unfenced and fenced plots. The comparison between the sasa and no-sasa forests suggested that removal of S. borealis by sika deer had an indirect positive effect on seedling emergence and survival. However, the fenced-plot experiments indicated that sika deer inhibited seedling emergence and survival. These contradictory conclusions could result from the much larger negative effects of S. borealis on seedling emergence and survival compared with the effects of sika deer browsing.     

Heartwood extractives from the Amazonian trees <Emphasis Type="Italic">Dipteryx odorata,Hymenaea courbaril</Emphasis>, and <Emphasis Type="Italic">Astronium lecointei</Emphasis> and their antioxidant activities

Heartwood extracts from Amazonian trees cumaru-ferro (Dipteryx odorata), jatoba (Hymenaea courbaril), and guarita (Astronium lecointei) exhibit antioxidant activities comparable with that of α-tocopherol, a well-known antioxidant. This article reports the characterization of the antioxidant compounds in the extracts of the three heartwoods. Silica gel column chromatography of the cumaru-ferro EtOAc extract yielded (−)-(3R)-7,2′,3′-trihydroxy-4′-methoxyisoflavan and (+)-(3R)-8,2′,3′-trihydroxy-7,4′-dimethoxyisoflavan. Silica gel column chromatography followed by preparative high-performance liquid chromatography of the jatoba EtOAc extract yielded (−)-fisetinidol and (+)-trans-taxifolin. Chemical structures were assigned using electron-ionization mass spectrometry, ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy including nuclear Overhauser effect spectroscopy (NOESY), as well as optical rotation and circular dichroism. Gas chromatography-mass spectrometry demonstrated that the isolated compounds were predominant in the EtOAc extracts. In the guarita EtOAc extract, catechin and gallic acid were identified by comparing their retention times and mass fragmentation patterns with those of authentic samples. Antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl assay demonstrated that all these compounds had activities comparable with that of α-tocopherol. Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007     

Water adsorption process of bamboo heated at low temperature

Water adsorption capacities were evaluated for moso bamboo samples that were heated at 200°C for various times and conditioned in a closed container at 97% relative humidity at 20°C. Logistic regression analysis was used for curve fitting to the adsorption data and its parameters were analyzed. These parameters were compared with those derived previously from the Dubinin and Radushkevich theory. The properties of the heat-treated samples changed after 5 h of heating. With less than 5 h of heating, hydroxyl groups provided the main adsorption sites but their numbers decreased on heating. After 5 h, gasifi cation of the bamboo increased and capillaries formed. Part of this article was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007     

Aluminum oxyhydroxide polymorphs and some micromorphological characteristics in sclerotium grains

The presence of aluminum oxyhydroxide and its micromorphological characteristics in sclerotium grains were examined by SEM, TEM, and EDX analyses. A spherical fraction with a diameter of 100 nm, which contained C and Al as the predominant elements, was recognized as the unit particle of the matrix of sclerotium grains. The Al polymorphs and the Si spherical structures found in the ignited grains were assumed to correspond to boehmite and opaline silica particles, respectively. SEMI analysis revealed the presence of a needle ball structure inside the hollow part of sclerotium grains. The relationship between the inner structure of sclerotium and biochemical processes of the host fungi was discussed.