Climate change can intensify drought in many regions of the world and lead to more frequent drought events or altered cycles of soil water status. Therefore, it is important to enhance the tolerance ...to drought and thus health, vigor, and success of transplantation seedlings used in the forestry by modifying fertilization and promoting mycorrhization. Here, we sowed seeds of Japanese larch (
Larix kaempferi
) in 0.2-L containers with 0.5 g (low fertilization; LF) or 2 g (high fertilization; HF) of slow-release fertilizer early in the growing season. One month later, we irrigated seedlings with non-sterilized ectomycorrhizal inoculum (ECM) or sterilized solution (non-ECM), and after about 2 months, plants were either kept well watered (WW; 500 mL water/plant/week) or subjected to drought (DR; 50 mL water per plant/week) until the end of the growing season. HF largely stimulated plant growth and above- and belowground biomass production, effects that are of practical significance, but caused a small decrease in stomatal conductance (Gs
390
) and transpiration rate (
E
390
), which in practice is insignificant. ECM treatment resulted in moderate inhibition of seedling growth and biomass and largely canceled out the enhancement of biomass and foliar K content by HF. DR caused a large decrease in CO
2
assimilation, and enhanced stomatal closure and induced senescence. DR also largely depleted foliar Mg and enriched foliar K. Although DR caused a large decrease in foliar P content in LF, it moderately increased P in HF. Likewise, DR increased foliar K in HF but not in LF, and decreased foliar P in ECM plants but not in non-ECM plants. Conversely, ECM plants exhibited a large enrichment in foliar P under WW and had a lower water potential under DR when grown in LF. These results indicate that the drought tolerance and health and vigor of Japanese larch seedlings can be modified by soil fertility and soil microorganisms. This study provides a basis for new multifactorial research programs aimed at producing seedlings of superior quality for forestation under climate change.
Pure cultures of Tuber were isolated from ectomycorrhizal root tips in Abies sachalinensis plantations in Hokkaido, Japan. Their phylogenetic relationships as well as vegetative hyphal ...characteristics on culture media were reported. Phylogenetic analysis based on the internal transcribed spacer within ribosomal DNA settled well-supported eight lineages within Puberulum, Latisporum, and Maculatum clades in Tuber. Three and one lineages were grouped with undescribed species of Puberulum clade in Japan and that of the Latisporum group in China, respectively. Two lineages were closely associated to but distinct from an undescribed species of Puberulum clade in Japan. One lineage did not group with any sequences in the International Nucleotide Sequence Database (INSD), proposing a new taxon in the Latisporum group. One lineage was grouped with T. foetidum in Maculatum clade. All strains in each lineage displayed yellowish white, thin, filamentous colonies on Melin-Norkrans agar medium. Various differences in morphological characteristics of hyphae on pure cultures of various strains were noted, but they were frequently uncommon among strains of the same taxa. Isolation from ectomycorrhizal root tips can be among the effective ways to acquire pure cultures of Tuber strains.
Amphipathic lignin derivatives (A-LDs) were already demonstrated to improve enzymatic saccharification of lignocellulose. Based on this knowledge, two kinds of A-LDs prepared from black liquor of ...soda pulping of Japanese cedar were applied to a fed-batch simultaneous saccharification and fermentation (SSF) process for unbleached soda pulp of Japanese cedar to produce bioethanol. Both lignin derivatives slightly accelerated yeast fermentation of glucose but not inhibited it. In addition, ethanol yields based on the theoretical maximum ethanol production in the fed-batch SSF process was increased from 49% without A-LDs to 64% in the presence of A-LDs.
The interactive effects of ozone, soil nutrient availability and root microorganisms on physiological, growth, and productivity traits were studied for the first time for Japanese larch (
Larix ...kaempferi
) seedlings grown in containers over a growing season, using a free air ozone-concentration enrichment exposure system. High nutrient availability altered leaf and root nutrient dynamics and enhanced plant growth; however, it also enhanced seedling susceptibility to damping-off disease compared to low nutrient availability. Negative effects of elevated ozone, as compared with ambient ozone, on leaf gas exchange and plant stem form were neither offset nor exacerbated by soil nutrient availability and root colonizers. Such negative effects suggest that elevated ozone may have implications for ecological health even when plant vigor is limited by factors other than ozone. Inoculation of roots with ectomycorrhizae had negligible influence on the effects of either soil nutrient availability or ozone. However, this lack of effect may be upon impeded formation of complete mycorrhizal root tips due to factors other than the manipulated variables. B and Na appeared to have an important role in stress responses, so further studies to examine their link with physiological mechanisms as a function of time. This study provides an important perspective for designing forestry practices to enhance seedling health.
Although compacted soil can be recovered through root development of planted seedlings, the relationship between root morphologies and soil physical properties remain unclear. We investigated the ...impacts of soil compaction on planted hybrid larch F1 (Larix gmelinii var. japonica×L. kaempferi, hereafter F1) seedlings with/without N loading. We assumed that N loading might increase the fine root proportion of F1 seedlings under soil compaction, resulting in less effects of root development on soil recovery. We established experimental site with different levels of soil compaction and N loading, where two-year-old F1 seedlings were planted. We used a hardness change index (HCI) to quantify a degree of soil hardness change at each depth. We evaluated root morphological responses to soil compaction and N loading, focusing on ectomycorrhizal symbiosis. High soil hardness reduced the total dry mass of F1 seedlings by more than 30%. Significant positive correlations were found between HCI and root proportion, which indicated that F1 seedling could enhance soil recovery via root development. The reduction of fine root density and its proportion due to soil compaction was observed, while these responses were contrasting under N loading. Nevertheless, the relationships between HCI and root proportion were not changed by N loading. The relative abundance of the larch-specific ectomycorrhizal fungi under soil compaction was increased by N loading. We concluded that the root development of F1 seedling accelerates soil recovery, where N loading could induce root morphological changes under soil compaction, resulting in the persistent relationship between root development and soil recovery.
Biochar is gaining increasing attention in the fields of forest rehabilitation, agriculture, etc. For evaluating biochar application to improve the rhizosphere environment of Japanese black pine ...(Pinus thunbergii) at harsh coastal environments, a pot experiment was carried out with a focus on ectomycorrhizal (ECM) symbiosis and water relations of seedlings. Another characteristic recently observed at coastal forests is the invasion of the locust (Robinia pseudoacacia), which can potentially increase soil nitrogen. In this study, four treatments were examined (biochar addition, litter addition, biochar and litter addition, and no addition control) to determine the effects of biochar and/or nitrogen-rich locust (Robinia pseudoacacia) litter application. Although effects of biochar and litter addition were not observed on ECM symbiosis rate and species composition, treatments with biochar addition, maintained xylem water potential (XWP) of needles for up to 2 weeks without irrigation, independent of litter addition. As biochar increased relative fine root biomass (fine root biomass/total root biomass), it can be considered that biochar was able to maintain needle XWP through increasing the relative amount of fine roots that can obtain water. Overall, these findings suggest that biochar application can help to maintain water relations of Japanese black pine by enhancing fine root growth.
Bacterial cellulose (BC)-producing bacterium,
Gluconacetobacter xylinus (ATCC53582), was found to move along linear microgrooves of a stripe-patterned cellulosic scaffold. On the basis of this ...finding, fabrication of honeycomb-patterned BC was attempted by controlling the bacterial movement using a agarose film scaffold with honeycomb-patterned grooves (concave type). The patterned agarose film was prepared by three steps. The first was transcription of a honeycomb-patterned polycaprolactone film template with polydimethyl siloxane. When the bacteria were cultured on the scaffold under atmospheric conditions, only bacterial proliferation was observed. Honeycomb-patterned BC was obtained when cultured under a humid CO
2 atmosphere. Electron diffraction and polarized microscopic observation showed that the patterned BC comprised of the well defined cellulose Iα microfibrils.
As another attempt to fabricate honeycomb-patterned BC, the bacteria were cultured on the patterned cellulose and agarose film with convex type of honeycomb. This culture yielded no honeycomb-patterned BC. Therefore, concave type honeycomb scaffold is more suitable to fabricate honeycomb-patterned BC.
D-Mannitol, one of the main phytochemicals of the edible Tamogi-take mushroom (Pleurotus cornucopiae), was found to inhibit an angiotensin I converting enzyme (ACE). The antihypertensive effect of ...D-mannitol and a hot water extract of Tamogi-take mushroom was demonstrated in spontaneously hypertensive rats (SHR) by oral administration.
To investigate the host specificity of Ophiocordyceps nutans against hemipteran insects in the wild, we determined the relationship between host species and rDNA-internal transcribed spacer (ITS) ...variation in O. nutans. The analyzed fungal specimens infected 16 host species belonging to four families of Hemiptera. The molecular phylogenetic analysis revealed that O. nutans can be classified into two types corresponding to their host families. The genetic distance values between the two types were very remote (>0.084), and the strains of O. nutans that parasitized Halyomorpha halys and Plautia crossota stali, well-known insect pests, formed a subclade. The results suggest that O. nutans should have host specificity which can be valuable for developing biological control agents against specific hemipteran insects.
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