The neutron-rich carbon isotopes 19,17C have been investigated via proton inelastic scattering on a liquid hydrogen target at 70 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum, in which fast neutrons and charged fragments were detected in coincidence using a neutron hodoscope and a dipole magnet system. A peak has been observed with an excitation energy of 1.46(10) MeV in 19C, while three peaks with energies of 2.20(3), 3.05(3), and 6.13(9) MeV have been observed in 17C. Deduced cross sections are compared with microscopic DWBA calculations based on p-sd shell model wave functions and modern nucleon-nucleus optical potentials. Jpi assignments are made for the four observed states as well as the ground states of both nuclei.Comment: 20 page
The ectomycorrhizal basidiomycete Tricholoma matsutake associates with members of the Pinaceae such as Pinus densiflora (red pine), forming a rhizospheric colony or "shiro," which produces the prized "matsutake" mushroom. We investigated whether the host specificity of T. matsutake to conifers is innately determined using somatic plants of Cedrela odorata, a tropical broad-leaved tree (Meliaceae) that naturally harbors arbuscular mycorrhizal fungi. We found that T. matsutake could form in vitro shiro with C. odorata 140 days after inoculation, as with P. densiflora. The shiro was typically aromatic like that of P. densiflora. However, this was a root endophytic interaction unlike the mycorrhizal association with P. densiflora. Infected plants had epidermal tissues and thick exodermal tissues outside the inner cortex. The mycelial sheath surrounded the outside of the epidermis, and the hyphae penetrated into intra- and intercellular spaces, often forming hyphal bundles or a pseudoparenchymatous organization. However, the hyphae grew only in the direction of vascular bundles and did not form Hartig nets. Tricholoma fulvocastaneum or "false matsutake" naturally associates with Fagaceae and was also able to associate with C. odorata as a root endophyte. With T. matsutake, C. odorata generated a number of roots and showed greatly enhanced vigor, while with T. fulvocastaneum, it generated a smaller number of roots and showed somewhat lesser vigor. We argue that the host-plant specificity of ectomycorrhizal matsutake is not innately determined, and that somatic arbuscular mycorrhizal plants have a great potential to form mutualistic relationships with ectomycorrhizal fungi.
We have studied the one-neutron removal reactions of 18 C at 81 MeV/nucleon and 19 C at 68 MeV/nucleon on a liquid hydrogen target. Transverse-momentum distributions of the core fragments 17 C and 18 C, and their partial cross sections, are measured using coincidences with the γ rays. These are compared to theoretical calculations based on the continuum-discretized coupled-channels (CDCC) method. We have found that the transverse-momentum distributions of 17 C are well described by the CDCC calculations, and the agreement provides evidence for the spin-parity assignments of J π = 1/2 + for the 0.21-MeV state and J π = 5/2 + for the 0.33-MeV state in 17 C. The J π = (2, 3) + assignment for the 4.0-MeV state in 18 C is obtained for the first time based on the momentum distribution of 18 C. The measured partial cross sections are consistent with the CDCC calculations combined with shell-model spectroscopic factors. The present study demonstrates that the transverse-momentum distribution obtained in a one-neutron removal reaction on a proton target is as useful as the conventional longitudinal-momentum distribution measured with the heavier Be or C targets for determining the orbital angular momentum of a removed neutron.
Matsutake mushroom Mycorrhizal isolationNuclear ribosomal RNA gene (rDNA) IGS1 region a b s t r a c t Tricholoma matsutake is one of the most highly valued ectomycorrhizal mushrooms, primarily associated with conifers. Here, we examined the association of T. matsutake with hemlock and fir species native to the subalpine forests of Japan. Basidiomata of T. matsutake were harvested from the forests of Honshu Island, Japan, along with two soil samples directly beneath the basidiomata; ectomycorrhizal root tips were also collected, and used for fungal isolation and molecular analyses. Mycorrhizal fungi were isolated from the roots of Abies veitchii (Veitch's fir) and Tsuga diversifolia (northern Japanese hemlock). These fungi were identified as T. matsutake based upon their production of whitish mycelial colonies on nutrient agar media, and confirmed using molecular analyses; the ectomycorrhizal association between T. matsutake and A. veitchii was also confirmed by mycorrhizal synthesis in vitro. This work represents the first description of T. matsutake ectomycorrhizations withAbies and Tsuga species, as well as a detailed morphological description of these associations. /locate /m yc m y c o s c i e n c e 5 6 ( 2 0 1 5 ) 4 0 2 e4 1 2 http://dx.
The Japanese golden chanterelle commonly identified as Cantharellus cibarius was sampled 3 in a broad range of forest vegetation. A total of 90 fresh and 11 herbarium specimens were 4 examined microscopically, subjected to sequencing analysis of their nuclear ribosomal RNA 5 (rDNA) and tef-1 genes, and their characteristics were compared with those of European C. 6 cibarius. Based on morphological and ecological characteristics, basidioma samples from 7 Japan were divided into four species. While specimens of Cantharellus sp. 4 from Hokkaido 8 Island were included in the European C. cibarius clade phylogenetically, the other three 9 species formed three unique clades. Among these, Cantharellus anzutake sp. nov. is sister to 10 the clade of C. cibarius and was widely sampled from the northern limit of Honshu Island to 11 the southern limit of Kumejima Island in Ryukyu Islands. Although C. anzutake was 12 morphologically similar to C. cibarius, the two species were phylogenetically distinct. Other 13 morphologically similar but genetically distinct chanterelle species from India exhibited 14 macroscopic and microscopic differences compared with C. anzutake.
We previously reported that Tricholoma matsutake and Tricholoma fulvocastaneum, ectomycorrhizal basidiomycetes that associate with Pinaceae and Fagaceae, respectively, in the Northern Hemisphere, could interact in vitro as a root endophyte of somatic plants of Cedrela odorata (Meliaceae), which naturally harbors arbuscular mycorrhizal fungi in South America, to form a characteristic rhizospheric colony or "shiro". We questioned whether this phenomenon could have occurred because of plant-microbe interactions between geographically separated species that never encounter one another in nature. In the present study, we document that these fungi formed root endophyte interactions and shiro within 140 days of inoculation with somatic plants of Prunus speciosa (=Cerasus speciosa, Rosaceae), a wild cherry tree that naturally harbors arbuscular mycorrhizal fungi in Japan. Compared with C. odorata, infected P. speciosa plants had less mycelial sheath surrounding the exodermis, and the older the roots, especially main roots, the more hyphae penetrated. In addition, a large number of juvenile roots were not associated with hyphae. We concluded that such root endophyte interactions were not events isolated to the interactions between exotic plants and microbes but could occur generally in vitro. Our pure culture system with a somatic plant allowed these fungi to express symbiosis-related phenotypes that varied with the plant host; these traits are innately programmed but suppressed in nature and could be useful in genetic analyses of plant-fungal symbiosis.
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