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Apiolaza L.,University of Canterbury | Chauhan S.,Institute of Wood Science and Technology | Hayes M.,University of Canterbury | Nakada R.,Forest Tree Breeding Center | And 2 more authors.
New Zealand Journal of Forestry | Year: 2013

Early selection by age two for wood quality attributes is possible provided the trees are tilted to separate normal wood from reaction wood. Experimental results for Pinus radiata and Eucalyptus globulus and E. regnans are presented in this paper. Source


Begum S.,Tokyo University of Agriculture and Technology | Begum S.,Bangladesh Agricultural University | Nakaba S.,Tokyo University of Agriculture and Technology | Yamagishi Y.,Tokyo University of Agriculture and Technology | And 8 more authors.
Annals of Botany | Year: 2012

Background and AimsLatewood formation in conifers occurs during the later part of the growing season, when the cell division activity of the cambium declines. Changes in temperature might be important for wood formation in trees. Therefore, the effects of a rapid decrease in temperature on cellular morphology of tracheids were investigated in localized heating-induced cambial reactivation in Cryptomeria japonica trees and in Abies firma seedlings.MethodsElectric heating tape and heating ribbon were wrapped on the stems of C. japonica trees and A. firma seedlings. Heating was discontinued when 11 or 12 and eight or nine radial files of differentiating and differentiated tracheids had been produced in C. japonica and A. firma stems, respectively. Tracheid diameter, cell wall thickness, percentage of cell wall area and percentage of lumen area were determined by image analysis of transverse sections and scanning electron microscopy.Key ResultsLocalized heating induced earlier cambial reactivation and xylem differentiation in stems of C. japonica and A. firma as compared with non-heated stems. One week after cessation of heating, there were no obvious changes in the dimensions of the differentiating tracheids in the samples from adult C. japonica. In contrast, tracheids with a smaller diameter were observed in A. firma seedlings after 1 week of cessation of heating. Two or three weeks after cessation of heating, tracheids with reduced diameters and thickened cell walls were found. The results showed that the rapid decrease in temperature produced slender tracheids with obvious thickening of cell walls that resembled latewood cells.ConclusionsThe results suggest that a localized decrease in temperature of stems induces changes in the diameter and cell wall thickness of differentiating tracheids, indicating that cambium and its derivatives can respond directly to changes in temperature. © 2012 The Author. Source


Akiba M.,Japan Forestry and Forest Products Research Institute | Ishihara M.,Japan Forestry and Forest Products Research Institute | Ishihara M.,Hokkaido Research Center | Sahashi N.,Japan Forestry and Forest Products Research Institute | And 4 more authors.
Plant Disease | Year: 2012

Pine wilt disease is one of the most serious epidemic tree diseases in Japan, and resistant pine trees have been developed through a breeding program. To evaluate resistance of resistant families of Japanese black pine, Pinus thunbergii, to the pinewood nematode, Bursaphelenchus xylophilus, isolated from the field, and to determine whether differentiation of pathogenicity to resistant pine families appears in the nematode isolates, seedlings of five resistant pine families were inoculated with 25 nematode isolates. Disease incidence 18 weeks after inoculation was significantly different among nematode isolates and among pine families but there was no interaction effect between nematode isolate and pine family. This indicates that nematode isolates did not have differential host specificity to resistant families of P. thunbergii. Isolate Shimabara, a test isolate of the breeding program, showed the same degree of virulence as the highly virulent isolates frequently used in experiments. However, more virulent isolates than Shimabara were found among the isolates collected from natural pine forest. This indicated that B. xylophilus populations with higher virulence than Shimabara exist in the natural population. These findings are important in development of more efficient breeding procedures for resistant pine trees. © 2012 The American Phytopathological Society. Source


Kurinobu S.,Forest Tree Breeding Center | Chigira O.,Forest Tree Breeding Center | Matsune K.,Sumitomo Forestry | Miura M.,Forest Tree Breeding Center | Naiem M.,Gadjah Mada University
Silvae Genetica | Year: 2013

Nine provenances of Albizia falcataria were planted at three square spacing levels (2, 3, and 4 m) in a split-plot design at Jember in East Java, Indonesia and measured annually for six years, which is three quarters of its rotation age. The effect of spacing on mean height development became progressively evident, due to the decline in growth at closer spacing caused by intensified competition, in six provenances, i.e., three provenances each from Java and East Indonesia, which were considered better adapted to the site because of their better growth and higher survival. On the contrary, the height growth curves of two provenances from New Guinea were almost identical, irrespective of spacing, indicating a lack of plasticity to the favorable environment at wider spacing. Dominant height was defined as the average of the five tallest trees per sub-plot (350 stems/ha), the growth curves at the three spacing levels were similar in the above-mentioned six provenances and were regarded as a single curve according to AIC-values. In contrast, dominant height growth curves of the New Guinea provenances were differentiated in the order of 2, 3, and 4 m spacing, approximately proportional to the intensity of choosing dominant trees per sub-plot. These results suggest that provenance variation exists for mean and dominant height and their response to different spacing. The cause of this variation was presumably attributable to the difference in competitive ability as well as the plasticity to the given environment. The use of dominant height for growth modeling of A. falcataria was found to be the most suitable for the adapted provenances. Source


Hiraoka Y.,Japan Forestry and Forest Products Research Institute | Kuramoto N.,Forest Tree Breeding Center | Ohira M.,Forest Tree Breeding Center | Okamura M.,Forest Tree Breeding Center | And 2 more authors.
Journal of Forest Research | Year: 2011

Rhus succedanea L. is cultivated in Japan for the wax that can be extracted from its fruits. We determined genetic data for specific traits associated with wax production (fruit number per cluster, FN, fruit weight, FW, number of clusters per area, CN, and wax content, WC) in five traditional cultivars and 13 newer clones. Data were collected over 4 years and alternate bearing was observed: 2001 and 2003 were years with high yields; in 2002 and 2004 yields were poor. The restricted maximum likelihood method was used to calculate (co)variance components for analysis. Broad sense heritability was estimated and ranged from low (FN and CN) to high (FW and WC) for the traits examined. There were positive genetic correlations between FW and WC and negative ones between FN and FW throughout the 4 years. Genetic correlations between CN and the other traits were positive in good crop years and negative in bad crop years. For each assessed clone, the four traits in the 4 years were evaluated using best linear unbiased predictors (BLUP) of the clonal breeding values. The BLUP scores for both FW and WC exhibited positive correlations between pairs of years, whereas there were positive BLUP correlations for CN when the high yield and low yield years were examined separately. The traditional cultivars and the newer clones were also characterized. Some of the clones were better than the traditional cultivars with regard to wax yield and reliability of production. The trait characteristics and the future breeding are discussed. © 2011 The Japanese Forest Society and Springer. Source

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