Cytological study of a male-sterile Cryptomeria japonica that does not release microspores from tetrads

To determine the mechanism of male-sterility Cryptomeria japonica tree Shindai3, the process of microspore development was observed under light and fluorescence microscopy. Microspore development in the Shindai3 was normal until the tetrad stage, but separation of the microspores from the tetrads was not observed even after callose had been degraded. In contrast to the microspore stage in a male-fertile tree, amorphous substances were observed around tetrads in the Shindai3, and the amount of the amorphous substance increased from the middle of November to the middle of December. The substances are hypothesized to prevent the separation of individual microspores from tetrads by inducing adhesion between microspore cells within the tetrad or enclosing the tetrads. The form of the tetrads in the Shindai3 was maintained until just before the pollen dispersal season, but they ultimately degenerated. The results of this study indicate that the mechanism causing male sterility in Shindai3 differs from that previously reported for other male-sterile trees of C. japonica.     

Predicting the site index of sugi plantations from GIS-derived environmental factors in Miyazaki Prefecture

We constructed sugi site index models using digital-terrain-analysis-based environmental factors for Miyazaki Prefecture. We selected 18 sugi plantation stands which were pure, undisturbed, and over 40 years old, planted with the same sugi-cutting cultivar, and managed by normal forest operations. The dominant tree in each stand was felled for stem analysis. Site index, defined here as dominant tree height at 40 years old, was estimated by stem analysis for each stand. Five types of DEMs were used: 100- and 50-m resolution derived from DEMs published by the Geographical Survey Institute, and 50-, 25-, and 12.5-m resolution derived from digital contour map manually generated from a 1:25,000 topographic map. A total of 14 indices categorized into solar radiation index, wetness index, and topographic exposure index were used to model the site index by multiple linear regression analysis. Through model selection procedures, the best-fitted site index models were selected for each type of DEM. The most precise model was that of the 12.5-m-resolution DEM (R ² = 0.692), following the model of the published 50-m-resolution DEM (R ² = 0.665). Site productivity of sugi was severely limited by direct solar radiation. Soil wetness also affected sugi site productivity; however, it can only be represented using a high-resolution DEM derived from fine-scale data. Our results suggest that the 50-m-resolution DEM published by the Geographical Survey Institute can be used for site index modeling.     

Inheritance of the trait of male sterility inCryptomeria japonica

Matings of male-sterileC. japonica and fertile eliteC. japonica, as well as backcross seedlings of male-sterile trees, were carried out to clarify the genetic trait of male sterility of theC. japonica. The seeds from male-sterileC. japonica were germinated in an incubator and grown them in the greenhouse between 1994 and 1997. The seedlings were treated with 100 ppm gibberellin at early July 1994 and early July 1995 to promote the formation of male flowers. In the middle of January 1995, the male flowers of all seedlings were examined under the microscope to confirm the production of pollen. In January 1996, pollen did not developed in to the male flowers from the seedlings between the fertiled elite and backcrossC. japonica. In January 1997, all seedlings of eliteC. japonica produced pollen in their male flowers; however, pollen did not developed in 55 out of 120 backcrossed seedlings. This evidence suggests that the heredity pattern of male sterility inC. japonica is nuclear male sterility controlled by a pair of recessive genes.     

Influences of genetic and environmental factors on the concentration of the allergen Cry j 1 in sugi (Cryptomeria japonica) pollen

Pollen from sugi (Japanese cedar, Cryptomeria japonica D. Don), a forest tree species that is widely grown in Japan, causes serious allergic disease. The major allergens from sugi pollen, Cry j 1 and Cry j 2, have been isolated and characterized. It has been reported that Cry j 1 concentration in pollen varies considerably among trees. If Cry j 1 concentration is genetically controlled, the planting of trees with low Cry j 1 concentrations would reduce pollinosis. We investigated genetic and environmental effects on Cry j 1 concentration in eight clones growing at four sites. Concentrations of Cry j 1 in pollen were measured with a monoclonal antibody-based Enzyme Linked Immunosorbent Assay (ELISA). The Cry j 1 concentrations differed significantly among clones and sites, but the site x clone interaction was not significant, suggesting that the Cry j 1 concentration is controlled primarily by genetic factors. We examined correlations between Cry j 1 concentration and temperature and precipitation from July through February. Temperature was not significantly related to Cry j 1 concentration, whereas cumulative precipitation during the 8 months and mean daily precipitation in September showed significant negative correlations with Cry j 1 concentration.     

Treatment of sugi （Cryptomeria japonica D.） sapwood with aqueous solution of acetic acid

Sugi sapwood samples were processed with aqueous solution of acetic acid in order to find the response of the weight of sugi sapwood and the treatment of aqueous solution of acetic acid. The result showed that loss of weight for the treated sugisapwood was about equal to yield of extracts from sugi sapwood, and increased with the increment of the concentration of aqueous solution of acetic acid. Fourier transform infrared spectroscopy spectra changes of the treated sugi wood and extracts from sugi sapwood were analyzed by FT-IR spectroscopic technique. Increasing tendency of absorption intensities of the stretching vibration at 3 400 cm^-1 of hydroxyl group (OH) and C=C in lignin stretching vibration at 1510 cm^-1 of benzene ring inlignin were observed from FT-IR of the treated sugi sapwood. From FT-IR spectra of extracts from sugi sapwood by aqueoussolution of acetic acid, the dissolution of lignin was observed during the treatment with 30% acetic acid solution aqueous.     

Plus tree of Cryptomeria japonica D. Don with a heterozygous male-sterility gene

To find plus tree clones of Cryptomeria japonica that are heterozygous for a male-sterility gene (Aa), we crossed a homozygous male-sterile tree (aa) with 63 clones. Male sterility in this case is controlled by a recessive allele at a single gene locus and is expressed only in homozygotes. All F₁ seedlings obtained by crossing the male-sterile mother tree and 62 out of the 63 clones produced pollen. In contrast, F₁ seedlings obtained from the crossing between the male-sterile mother tree and a plus tree clone, Ohara 13, produced 64 male-sterile individuals and 52 fertile individuals. The segregation ratio fitted the expected 1 : 1 ratio according to a chi-square test. These results clearly demonstrate that the Ohara 13 clone is heterozygous for a male-sterility gene.     

Effects of stand density on the productivity ofCryptomeria japonica male flowers

We have studied male flower production and relative illumination in clonal sugi (Cryptomeria japonica) forests planted at densities of 1,500/ha, 3,000/ha, and 5,000/ha, to clarify the effects of forest management on male flower production. Both the relative illumination and male flower production decrease as the stand density increases. The lowest position at which male flowers are formed decreases as the density of the stand decreases. High thinning intensity promotes male flower production and light pruning is ineffective to reduce male flower production. Therefore, traditional management methods used in sugi forests (i.e. planting at high density, frequent light thinning, intensive pruning and short rotation) are ideal strategies for limiting male flower production.     

Induction of the biosynthesis of agatharesinol, a norlignan, in sapwood sticks of Cryptomeria japonica under humidity-regulated circumstances

To establish an experimental approach for studying the biosynthetic pathway of agatharesinol, a norlignan, induction of the formation of agatharesinol in Cryptomeria japonica (Japanese cedar, sugi) was attempted. Wood sticks were prepared from the sapwood immediately after cutting a sugi tree down, and they were allowed to stand in desiccators in which the humidity was adjusted to 76% and 88%, and in a room. When the wood sticks were allowed to stand in 76% humidity and in a room, they dried rapidly and no formation of agatharesinol was demonstrated by gas chromatography-mass spectrometry. These results suggest that in the sapwood dried rapidly, the cells that were biologically active in the sapwood, probably ray parenchyma cells, die rapidly and completely before the biosyntheses of secondary metabolites including agatharesinol was wholly established. The wood sticks allowed to stand in 88% humidity, on the other hand, dried gradually compared with the sticks placed in 76% humidity and in a room, and agatharesinol was formed as one of the predominant ethyl acetate extractives. These results suggest that delaying the drying of the sapwood sticks can control the dying period to an appropriate length for the ray parenchyma cells, during which the biosynthesis of agatharesinol is induced. Part of this study was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004     

Chemical changes in terpenes of sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) wood during steam drying in kiln at high temperature

Sawdusts of sugi (Cryptomeria japonica) wood prepared before and after steam drying at 120°C in a kiln were extracted with n-hexane and ethyl acetate to give n-hexane extracts and ethyl acetate extracts. From gas chromatography-mass spectrometry analysis of the ethyl acetate extracts from woods before and after steam drying, the components of 4-epi-cubebol, cubebol, and 2,7(14),10-bis-abolatrien-1-ol-4-one, which existed in the raw sugi wood, were proved to disappear in the steam-dried wood. These components were also absent in the ethyl acetate extract of the steam-condensed solution of waste steam from the kiln outlet. When these three components were treated with 0.2% (v/v) acetic acid solution at 120°C, δ-cadinene was produced as a major product from both 4-epi-cubebol and cubebol by dehydration and cleavage of the cyclopropane ring, and cryptomerone from 2,7(14),10-bisabolatrien-1-ol-4-one by hydration. The chemical changes of the three components presumably occur during steam drying of the sugi wood. This study was presented in part at the 85th Spring Meeting of the Chemical Society of Japan, Kanagawa, Japan, March 26–29, 2005     

Environmental effects on the color of sugi (Cryptomeria japonica D. Don) heartwood

Sugi (Cryptomeria japonica D. Don) is one of the most important planted trees in Taiwan. The normal heartwood of sugi has a red to pinkish rose color. Unfortunately, this pleasant appearance is susceptible to discoloration after environmental exposures. This discoloration is a serious defect that decreases the value of sugi products. The objective of this study was to investigate the effects of environmental factors such as moisture, oxygen, and lights of different wavelengths on the discoloration of sugi. The results show that under the combined effects of light and oxygen the color of heartwood changes from red (or rosepink) to bluish green. The color further darkens and eventually turns to black with the presence of moisture. As for the effect of light wavelengths on the discoloration of sugi heartwood, it was found that the red color was enhanced after being irradiated with light of wavelengths above 600 nm. Botha ^* andb ^* values increased significantly as a result of such exposure.     

Cultivation of <Emphasis Type="Italic">Pleurotus eryngii</Emphasis> on umbrella plant (<Emphasis Type="Italic">Cyperus alternifolius</Emphasis>) substrate

Mycelial growth and mushroom yields of three strains of Pleurotus eryngii produced on wheat bran-supplemented umbrella plant (Cyperus alternifolius) substrate were assessed using surface brightness, bromophenol blue color reactions, ergosterol and glucosamine contents, and water potential as indicators of strain performance. Mycelial growth was 31%–46% greater, depending on strain, on the umbrella plant substrate compared with the mushroom industry standard sugi (Cryptomeria japonica) substrate. Mushroom yields on the first flush were 20%–23% higher, depending on strain, on the plastic bottle-contained umbrella plant substrate. However, yields on the second break were lower from the umbrella plant substrate. Because many growers in Japan only harvest one flush, production of P. eryngii on umbrella plant substrate may offer commercial producers an alternative basal ingredient to diminishing supplies of sugi sawdust.Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002.     

不育紫薇花粉活力及柱头可授性研究

以4年生"不育紫薇"和普通"可育紫薇"为研究对象,进行杂交育性分析,并利用液体培养法和荧光显微技术测定了两个紫薇品种的花粉活力和柱头可授性。结果表明:"不育紫薇"的花药表面较光滑湿润,难以释放花粉;花粉粒畸形,不能萌发,没有生活力;雌蕊的柱头对正常成熟的花粉有亲和力,具有可授性,但结实率仅4.0%。"不育紫薇"的不育性状由雄性不育和雌性不育共同作用所致。     

Individual variations in monoterpenes released from Cryptomeria japonica and Pinus thunbergii needles

Variations in the compositions of low boiling point (LBP) monoterpenes in needle samples from 99 sugi (Cryptomeria japonica) and 100 kuromatsu (Pinus thunbergii) trees were investigated using a headspace technique. Considerable variations in the proportions of monoterpenes were revealed in both species. In sugi, the proportions of sabinene and α-pinene in the total LBP monoterpenes, ranging from 8.8% to 73.3% and from 14.5% to 73.3%, respectively, showed enormous variations among nine monoterpenes. The proportions of 3-carene and limonene, ranging from 0.1% to 29.5% and from 0.2% to 20.4%, respectively, also showed very specific variations. In kuromatsu, the proportions of β-pinene and α-pinene in the total LBP monoterpenes, ranging from 26.5% to 66.3% and from 18.7% to 46.9%, respectively, showed considerable variations among ten monoterpenes. The proportions of myrcene and 1,8-cineole, ranging from 0.9% to 18.5% and from 0.8% to 12.3%, respectively, also showed specific variations. Part of this article was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April, 2000, and the 13th Annual Meeting of the Chugoku Shikoku Branch of the Japan Wood Research Society, Okayama, September 2001     

Study of sugi (Cryptomeria japonica D. Don) with male-sterility gene using CAPS markers

The frequency of open-pollinated male-sterile seedlings from a male-sterile mother tree in Cryptomeria japonica D. Don was determined in 765 open-pollinated seedlings. Pollen was not formed by 29 out of the 765 seedlings. To find pollen donor candidates for 29 male-sterile seedlings, a male-sterile tree was crossed with five individuals in the neighborhood of the mother tree. Analysis of microspores in male flowers of F₁ seedlings revealed that one of the five individuals had a heterozygous male-sterility gene. Paternity tests were conducted on the 29 male-sterile seedlings using eight kinds of CAPS markers in C. japonica. The pollen parents of 29 male-sterile seedlings were not only a tree in the neighborhood of the mother tree, but also other trees. Since it was found that the pollen parents of four of the male-sterile seedlings were not in the study plot, it was inferred that C. japonica trees that possess the male-sterility gene grow in other places and may be widely distributed.     

Improvement of penetrability of sugi wood by impregnation of bacteria using sap-flow method

The sap flow method of wood impregnation was conducted to aid the movement of bacteria through the living tree, thereby accelerating their distribution through wood within a short time. When log-pond water containing mixed species of bacteria were introduced in the living trees by butt-end dipping and then laid horizontally for 6 months, bacteria could be delivered by sap flow vertically through the sapwood tracheids up to the high portions from the butt-end of trees; they could be detected in the ray parenchymal cells. The sap-flow method was assumed to deliver the bacteria to sapwood and heartwood at high levels of standing sugi (Cryptomeria japonica D. Don) trees. Degradation of the pit membranes was observed even at more than 3 m upward from the butt-end after the treatment in sapwood, as well as around the butt-end of the trees. The uptake of the aqueous dye solutions in sapwood of the treated logs were about eight times more than those of control specimens after 8h.Part of this report was presented at the 40^th annual meeting of the Japan Wood Research Society, Tsukuba, April 1990; the 41^st annual meeting of Japan Wood Research Society, Matsue, April 1991; and the IUFRO 4^th international conference on wood drying, Rotorua, New Zealand, August 1994     

A low <Emphasis Type="Italic">Platypus quercivorus</Emphasis> hole density does not necessarily indicate a small flying population

The ambrosia beetle Platypus quercivorus causes mass mortality of Fagaceae trees in Japan, and tree species differ in their susceptibility to P. quercivorus. We hypothesized that interspecific differences in susceptibility are caused by differences in beetle infestation patterns, that is, how many beetles fly to a tree and how many of those arriving bore holes. To examine how tree susceptibility is related to these parameters, two tree species with different degrees of susceptibility were studied (highly susceptible Quercus crispula and less susceptible Q. salicina). Specifically, we measured the number of male beetles per unit area that flew to the host trees (NFM) and the density of holes bored by male beetles (DH). From these two values, we calculated the proportion of male beetles flying to a host tree that bored holes (PBM). These parameters were compared for the two Quercus species. Although the two species did not differ in NFM in 2003, PBM was markedly lower for Q. salicina than for Q. crispula and DH was significantly lower for Q. salicina than for Q. crispula. Thus, the lower susceptibility of Q. salicina is partly explained by its low PBM.     

Representation of tree stem taper curves and their dynamic, using a linear model and the centroaffine transformation

One main task of forestry is a reliable estimation of the stem form and its development applied in calculating total and log volume. As long as process-oriented models are not available for this practical use, empirical models must serve instead. Taper curve data of trees within stands normally show a rank maintenance,i.e., a tree which has a greater diameter than another one at a certain height, is most probably bigger at any other height, too. This property also applies to the analysed tree species, sugi (Cryptomeria japonica) and hinoki (Chamaecyparis obtusa), and will be well-represented by a linear model formulation. As model parameter sets of single stands have a very limited time validity, two approaches for future stem form prediction are discussed. The one, the centroaffine transformation of a linear taper curve function, is not suitable for representing the time-depending change of the stem form. However, this can be done by a linear unit taper curve model, the parameters of which are based on sample trees of stands of several age classes. Temporary unit parameter sets are derived for sugi and hinoki and the estimated stand volumes are compared to the real ones to evaluate the model performance, which turned out to be very good. We would like to express our gratitude to the Japan Science and Technology Corporation for the financial promotion, which enabled this research work.     

The penetration rate of laser pulses transmitted from a small-footprint airborne LiDAR: a case study in closed canopy, middle-aged pure sugi (Cryptomeria japonica D. Don) and hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.) stands in Japan

Penetration rates of laser pulses transmitted from a small-footprint airborne light detection and ranging (LiDAR) system in closed-canopy, middle-aged (40–50 years old) hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.) and sugi (Cryptomeria japonica D. Don) plantations that had similar levels of canopy openness were studied. The number of transmitted pulses was 107 427 points/ha for the hinoki cypress stand and 122 883 points/ha for the sugi stand. The penetration rates of the first (P_f) and second pulses (P_s) that reached the ground were 0.1% and 1.0% in the hinoki cypress stand, and 2.6% and 5.5% in the sugi stand, respectively. Penetration rates for the total number of pulses (P_f+s) that reached the ground within each stand were 1.1% and 8.1%, respectively, and values for P_f+s, P_f, and P_s for sugi and hinoki cypress stands were significantly different (P < 0.001). The results of this study indicated that the generation of accurate digital terrain models in dense hinoki cypress stands with complex topographies using only the data from laser pulses with poor laser penetration rates is likely to be difficult.