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11.
12.
Morphological mutation of Lentinula edodes mycelium, particularly detectable in the dikaryotic state
A morphological mutation particularly detectable in the dikaryotic state was found in Lentinula edodes. The mutant dikaryon was readily distinguishable from the normal dikaryon by the irregularly branched short hyphae, very
slow hyphal growth, and sparse aerial hyphae. Genetic analysis revealed that expression of this mutation was controlled by
a single recessive gene, mor-13. Linkage analysis showed that the mor-13 was not linked to either the incompatibility factors (A and B) or the five kinds of mor genes that were segregated independently of each other in a previous study.
Contribution no. 380 from the Tottori Mycological Institute 相似文献
13.
MARIA U. DELMONTE CORRADO DONATA LOCATELLI LAURA PALEARI GIOVANNI BOTTIROLI 《The Journal of eukaryotic microbiology》1997,44(6):603-608
ABSTRACT. Mating pair formation in Paramecium primaurelia was shown to be inhibited by incubating mating-competent mating type (mt) I and mt U cells with Limulus polyphemus agglutinin (LPA) or wheat germ agglutinin (WGA). Preincubation of LPA and WGA with their specific binding-monosaccharides, N-acetylneuraminic acid (NeuAc) and N-acetylglucosamine (GlcNAc), respectively, prevented the lectin effect on pair formation. Addition either of NeuAc or GlcNAc resulted in a reversal of cell pairing inhibition by LPA or WGA, respectively. Both NeuAc and GlcNAc monosaccharides inhibited pair formation when their concentration exceeded a threshold value. The pattern of the relative distribution of NeuAc and GlcNAc molecules on the cell surface was analyzed using fluorescence resonance energy transfer techniques combined with imaging systems. Mt I1 cells showed a high lectin-binding site density localized just on the surface region engaged in conjugation. The pattern of mt I cells, consisting of a quite homogeneous lectin-binding site density spread on the cell surface, was also common to nonmating-competent cells and to immature cells. These findings suggest that in P. primaurelia pair formation involves both NeuAc and GlcNAc residues and that the development of mating-competence is related to a modification in NeuAc and GlcNAc relative distribution on the cell surface of mt 11 cells. 相似文献
14.
G. Karrer 《Plant Ecology》1985,59(1-3):199-209
Five plant communities contrasting in successional status and human impact from the southern part of the ‘Wienerwald’ (Austria) are analyzed using vegetation relevés, spectra of area types and a newly proposed disjunction quotient. A climax community (Asperulo-Fagetum), a subclimax community (Querco-Carpinetum s.l.), an anthropogenous substitute community (Mesobromion) and two natural, non-climax permanent communities (Euphorbio saxatilis-Pinetum nigrae and Fumano-Stipetum eriocaulis) are recognized. The disjunction quotient is defined as the number of partial (discontinous) areas divided by the size of the total area of distribution of a species. In particular, the average disjunction quotients of the species in the first two communities reflect relatively table environments only slightly influenced by man, with many ancient, stable taxa. These communities are characterized by species with well-delimited, stable distribution areas. The species in the Mesobromion community have very low average disjunction quotients as its component species are widely and continuously distributed and are often promoted by man. In contrast to these communities, the species linked to the natural permanent, non-climax communities of extreme habitats, have high distribution quotients i.e. small, disconinuous areas; this illustrates the relic character of these plant communities and of the eastern edge of the Alps is a whole. Using the highly variable disjunction quotient of all species and communities examined, the concepts of climax and permanent communities (of different origin) are discussed with regard to European conditions. 相似文献
15.
Since cacti have very small surface/volume ratios, the amount of light they intercept is limited, and so is photosynthesis. However, many cacti shade themselves by means of dense hairy mats, called cephalia, which protect the floral buds. There is a trade-off between allocating a surface to photosynthesis or to the protection of reproductive structures. We found that proportion of the stem covered by cephalium affected fitness in the columnar cactus Lophocereus schottii. Too little cephalium holds few floral buds while too much reduces fecundity – probably through diminished photosynthesis – with an intermediate amount maximising reproduction. The optimal proportion of cephalium becomes smaller as the plant grows, probably because self-shading by new branches causes a further reduction in light interception. Smaller plants had significantly less cephalium than the optimal amount to maximise current reproduction. Since the largest individuals produced more reproductive structures, small cacti may find it more profitable to grow fast to achieve a large fecundity, than to assign resources to immediate reproduction via cephalium development. 相似文献
16.
The biological activities of a sterile red fungus (SRF) capable of plant growth promotion and suppression of take-all disease
were investigated in soils collected from Lancelin, Newdegate and Mt. Barker regions of Western Australia. Further, the effects
of three wheat cultivars and the presence of two isolates ofStreptomyces on the biological activities of the SRF were tested using the Lancelin soil. The biological activities of the SRF were greatest
in the Lancelin and Newdegate (wheat field) soils and with the wheat cultivar Gutha. In in vitro studies the soil streptomycetes
tested showed either a significant increase in the exudate production by the SRF, which had antifungal and growth promoting
properties, or an inhibition of growth of the fungus. Streptomycete A63 which stimulated the exudate production by the SRF
in vitro, however, did not enhance disease protection in vivo. On the other hand, protection from root rot by the SRF in vivo
was reduced in the presence of the streptomycete isolate Ax which is capable of inhibiting the growth of the SRF in vitro. 相似文献
17.
18.
C. Benito C. Zaragoza F. J. Gallego A. de la Peña A. M. Figueiras 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,82(1):112-116
Summary The segregation of isozymic loci for leaf peroxidases (L2Per) has been investigated in backcrosses and F2 offspring of rye lines having purple seeds (Ps) and monstrosum ears (mo). The Ps, L2Per-3b, mo, and L2Per-2 loci were linked. The Ps and mo loci have been previously located on the 2R chromosome, and the L2Per-3b and L2Per-2 loci have been located on the 2RS chromosome arm. The results favor the gene order Ps ... L2Per-3b ... mo ... L2Per-2 or Ps ... mo... L2Per-3b ... L2Per-2. The position of the loci relative to the centromere is still not known, but the obtained results suggest that the mo locus could be located on the 2RS chromosome arm. On the basis of previously reported linkage groups, the most probable arrangement of the loci located on chromosome 2R is: dw2 ... Ps ... (L2Per-3a ... L2Per-3b ... mo) ... L2Per-2. It has not been possible to know the position of L2Per-4 loci (also located on 2RS chromosome arm) relative to L2Per-3a and L2Per-3b loci. 相似文献
19.
20.
Bird specimens collected by 19th century explorer and ornithologist Prince Maximilian of Wied-Neuwied form one of the foundation collections of the American Museum of Natural History in New York. However, parts of his collection remained in Germany and came to the Museum Wiesbaden. Since Wied described numerous new species without designating types, some of these specimens might be type material. Here we present a catalog of the 30 Wiesbaden specimens associated with him and discuss their potential type status. We conclude that 17 individuals in 11 species are potential type specimens that should be considered in future taxonomic work. 相似文献