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1.
Myxotrichum ochraceum var.frigidum, a new variety ofMyxotrichum, is described and illustrated from the material from Japanese soil. It is morphologically characterized by dull green to black ascomata with a yellow-orange centrum, peridium consisting of a fragile hyphal network, peridial hyphae with internal coiled branches and short spine-like appendages, pale yellow fusiform striate ascospores, and the absence of an anamorph. The new variety primarily differs from the type variety in the absence of elongate appendages. A key to all accepted species of the genus is revised. 相似文献
2.
Shinnosuke Miyauchi 《Mycoscience》2000,41(1):87-89
Cortinarius elatior var.albipes var. nov., found in the deciduous forest is described and illustrated. It is distinguished from the type variety by having
a white stipe and longer spores. The differences betweenCortinarius elatior var.albipes and similar taxa are briefly discussed. 相似文献
3.
Genetic studies of mutations at two loci of Drosophila melanogaster which cause a wide variety of homeotic transformations 总被引:1,自引:0,他引:1
Allen Shearn Evelyn Hersperger Grafton Hersperger 《Development genes and evolution》1987,196(4):231-242
Summary The ash-1 locus is in the proximal region of the left arm of the third chromosome of Drosophila melanogaster and the ash-2 locus is in the distal region of the right arm of the third chromosome. Mutations at either locus can cause homeotic transformations of the antenna to leg, proboscis to leg and/or antenna, dorsal prothorax to wing, first and third leg to second leg, haltere to wing, and genitalia to leg and/or antenna. Mutations at the ash-1 locus cause, in addition, transformations of the posterior wing and second leg to anterior wing and second leg, respectively. A similar spectrum of transformations is caused by mutations at yet another third chromosome locus, trithorax. One extraordinary aspect of mutations at all three of these loci is that they cause such a wide variety of transformations. For mutations at both of the loci that we have studied the expression of the homeotic phenotype is both disc-autonomous (as shown by injecting mutant discs into metamorphosing larvae) and cell autonomous (as shown by somatic recombination analysis). The original mutations which identified these two loci, although lethal, manifest variable expressivity and incomplete penetrance of the homeotic phenotype suggesting that they are hypomorphic. The phenotype of double mutants which were synthesized by combining different pairs of those original mutations manifest for two of the four pairs a greater degree of expressivity and slightly more penetrance of the homeotic transformations. This mutual enhancement suggests that the products of both loci interact in the same process. A third double mutant expresses a discless phenotype.Additional alleles have been recovered at both the ash-1 and the ash-2 loci. Some of these alleles as homozygotes or transheterozygotes express the wide range of transformations revealed first by double mutants. One of the alleles at the ash-1 locus when homozygous and several transheterozygous pairs can cause either the homeotic transformation of discs or the absence of those discs. The fact that these two defects, absence of specific discs and homeotic transformations of those same discs can be caused by mutations within a single gene suggests that the activity of the product of this gene is essential for normal imaginal disc cell proliferation. Loss of that activity leads to the absence of discs, whereas, reduction of that activity leads to homeotic transformations. 相似文献
4.
A new variety ofTalaromyces, T. wortmannii var.sublevisporus, is described and illustrated. It is characterized by producing nearly smooth-walled ascospores. The other characters are almost identical with those of the type variety. Based on observations of several strains including the authentic ones,T. assiutensis is considered a finely rough-spored variety ofT. trachyspermus. 相似文献
5.
High molecular weight ribosomal RNA components and their pattern of loss on ageing of excised leaf sections were the same in the non-yellowing mutant and the normal genotype of Festuca pratensis even though the mutant showed retarded chlorophyll loss. Thus it appears that the genetic lesion does not extend to changes in the ribosomal RNA components of chloroplasts or cytoplasm. 相似文献
6.
Aoyagi H 《Biotechnology letters》2006,28(20):1687-1694
An index [kv: average isolation rate of viable protoplast (number/ml min)] was established to evaluate the optimal conditions for protoplast isolation from cultured plant cells. The optimal conditions for protoplasts isolation from Nicotiana tabacum BY2 cultured cells could be determined on the basis of the kv [31.7 × 103 (number/ml min)]. The colony-forming efficiency of the protoplasts was about 46%. The optimal conditions for protoplasts isolation from Catharanthus roseus [kv = 38.1 × 103 (number/ml min)] and Wasabia japonica [kv = 14.2 × 103 (number/ml min)] cultured cells could also be determined. Furthermore, a method for rapid regenerating cell wall of protoplast in liquid culture using alginate gel containing locust bean gum was developed. 相似文献
7.
S. S. Karataglis 《Plant Systematics and Evolution》1989,163(1-2):13-20
A native population ofAegilops cylindrica was encountered for the first time in Greece in 1980 (near Kastoria, NW. Greece), completely isolated and at a great distance from its main distribution area. There are morphological and chromosomal, but no protein and esterase pattern differences from otherAe. cylindrica populations. This justifies the recognition of a new variety: var.kastorianum. Our comparative and karyotypic observations support the view thatAe. caudata var.polyathera and not var.caudata (typica) is the possible donor of genome C of the new variety. 相似文献
8.
Yukari Mizuta 《Mycoscience》2006,47(6):380-384
Two new species and one new variety of Oudemansiella (Agaricales) from Japan are described and illustrated: (1) Oudemansiella latilamellata sp. nov. (subgenus Xerula, section Radicatae) has relatively broad lamellae and broadly ellipsoid spores with a subacute apex; (2) Oudemansiella rhodophylla sp. nov. (subgenus Xerula, section Radicatae), growing in deciduous forests of Fagus crenata, Quercus crispula, etc., is characteristic in having lamellae tinted reddish; and (3) Oudemansiella amygdaliformis var. bispora var. nov. (subgenus Xerula, section Albotomentosae) is distinguished from the type variety by having two-spored basidia and grows in evergreen oak forests (Castanopsis sieboldii, Quercus glauca, etc.) or bamboo groves. 相似文献
9.
Seasonal migration promoting assortative mating in Littorina brevicula on a boulder shore in Japan 总被引:1,自引:1,他引:0
Yoshitake Takada 《Hydrobiologia》1995,309(1-3):151-159
Littorina brevicula Philippi is one of the most common snails found in the upper intertidal zone of Japan. In Amakusa, some of the population
of L. brevicula migrate to the lower zone in the winter, while the rest stay in the upper zone. Thus, during the winter, which is its reproductive
season, the population of L. brevicula divides into two sub-populations. This leads to a hypothesis that the migration pattern in winter is genetically controlled
and this behavioural dimorphism is maintained by reproductive isolation between the two sub-populations. In order to test
this hypothesis, the following three points were investigated: (1) whether the same snails migrate in a similar way every
winter, (2) whether there is a significant tidal level preference in snails, and (3) whether reproductive isolation occurs
between the two sub-populations. The results showed (1) the migration behaviour of each snail was consistent over two successive
winters, i.e. the same group of snails migrated downward every winter and the same group of snails stayed in the upper zone
every winter, (2) transplanted snails moved toward the original zones where they were caught, suggesting that the snails actively
selected their tidal zone in winter, and (3) most of the snails copulated within each sub-population. Therefore, reproductive
isolation between the two sub-populations was considered to be established to some extent by the dimorphic migration behaviour.
In conclusion, the migratory behaviour of L. brevicula is determined separately for each individual and might be genetically controlled, and the behavioural dimorphism may be maintained
by partial reproductive isolation between the two sub-populations. 相似文献
10.
G. I. Naumov 《Microbiology》2000,69(3):338-342
Partial genetic isolation of twoSaccharomyces bayanus varieties, 5.bayanus var.bayanus andS. bayanus var.uvarum comb, nov., was established by hybridological analysis. The hybrids of these two varieties were semisterile: their ascospores
were characterized by low survival. Earlier, the new variety was described as a group of cryophilic wine yeast cultivars capable
of fermenting melibiose. 相似文献
11.
Identification of QTLs for resistance to Fusarium head blight, DON accumulation and associated traits in the winter wheat variety Arina 总被引:3,自引:0,他引:3
Draeger R Gosman N Steed A Chandler E Thomsett M Srinivasachary Schondelmaier J Buerstmayr H Lemmens M Schmolke M Mesterhazy A Nicholson P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(5):617-625
Fusarium head blight (FHB) of wheat has become a serious threat to wheat crops in numerous countries. In addition to loss
of yield and quality, this disease is of primary importance because of the contamination of grain with mycotoxins such as
deoxynivalenol (DON). The Swiss winter cultivar Arina possesses significant resistance to FHB. The objective of this study
was to map quantitative trait loci (QTL) for resistance to FHB, DON accumulation and associated traits in grain in a double
haploid (DH) population from a cross between Arina and the FHB susceptible UK variety Riband. FHB resistance was assessed
in five trials across different years and locations. Ten QTL for resistance to FHB or associated traits were detected across
the trials, with QTL derived from both parents. Very few of the QTL detected in this study were coincident with those reported
by authors of two other studies of FHB resistance in Arina. It is concluded that the FHB resistance of Arina, like that of
the other European winter wheat varieties studied to date, is conferred by several genes of moderate effect making it difficult
to exploit in marker-assisted selection breeding programmes. The most significant and stable QTL for FHB resistance was on
chromosome 4D and co-localised with the Rht–D1 locus for height. This association appears to be due to linkage of deleterious genes to the Rht-D1b (Rht2) semi-dwarfing allele rather than differences in height per se. This association may compromise efforts to enhance FHB resistance
in breeding programmes using germplasm containing this allele. 相似文献
12.
Until the present decade, no studies had been conducted in Puerto Rico on the saprophytic distribution and variety of Cryptococcus neoformans. Samples (522) of pigeon droppings from 14 western towns were tested for the presence of C. neoformans. The yeast was recovered from 24.7% (129 isolates) of the samples, representing 10 of the 14 towns studied. All environmental isolates were identified as C. neoformans var. neoformans using canavanine-glycine-bromthymol blue (CGB) agar. The yeast was isolated from 79.4% of the samples in one town, Isabela. The average number of yeast cells isolated from sites within this municipality was 5.1×105 per gram of pigeon droppings. This was 2.6 times the average number of yeast cells of C. neoformans isolated from sites in other towns. In addition, the yeast was isolated from four patients with the acquired immune deficiency syndrome (AIDS), each of whom died of cryptococcal meningitis. Each of these poorly encapsulated isolates was identified as C. neoformans var. neoformans using CGB agar. The results of this investigation demonstrate that C. neoformans var. neoformans is prevalent in Puerto Rico.This paper was presented in part at the Xth Congress of the International Society for Human and Animal Mycology, Barcelona, Spain from June 27 to July 1, 1988. 相似文献
13.
Quan-Sheng Zhang Xue-Xi Tang Yi-Zhou Cong Shan-Cun Qu Shi-Ju Luo Guan-Pin Yang 《Journal of applied phycology》2007,19(4):303-311
Laminaria longissima and Zaohoucheng No.1 (a commercial variety selected from Laminaria japonica) differ to a certain extent in their morphological characteristics and biological habits. It was assumed that varieties bred
through their hybridization should exhibit high yield potential and tolerate relatively high seawater temperatures. Female
gametophyte clones isolated from L. longissima were crossed with male clones isolated from Zaohoucheng No.1. Laminaria variety 90-1 was obtained after gametophyte crossing, continuous self-crossing and selection. This variety was genetically
homozygous; the indices of variation of blade length, width and thickness of the final two selection cycles were 7–8%; i.e.,
not different significantly. Variety 90-1 grew faster, lost less tissue and had higher yield potential than two widely used
commercial varieties of L. japonica (all commercial varieties currently used in China originate from this latter species). The blade of variety 90-1 increased
3.71 cm day−1 on average during the whole period of cultivation, almost two-fold that of two controls, and growth was maintained even when
seawater temperature was higher than 18°C–3°C higher than the temperature tolerated by other Laminaria varieties. Variety 90-1 increased yield by more than 70% over two controls and also synthesized desirable amounts of iodine,
mannitol and algin. In blade length, variety 90-1 was more similar to L. longissima than to L. japonica, but more similar to L. japonica in blade width and thickness. Since the adoption of variety 90-1 in 1999, its culturing area has increased each year to reach
its current area of 7,000 ha, i.e., almost one-third of the total cultivation acreage of Laminaria in China. Breeding of variety 90-1 has demonstrated that it is feasible to develop elite Laminaria varieties by crossing gametophytes from different Laminaria species in combination with successive self-crossing and selection. 相似文献
14.
15.
The sexual isolation among the related species Drosophila melanogaster, D. simulans and D. mauritiana is asymmetrical. While D. mauritiana males mate well with both D. melanogaster and D. simulans females, females of D. mauritiana discriminate strongly against males of these two species. Similarly, D. simulans males mate with D. melanogaster females but the reciprocal cross is difficult. Interspecific crosses between several populations of the three species were
performed to determine if (i) males and females of the same species share a common sexual isolation genetic system, and (ii)
males (or females) use the same genetic system to discriminate against females (or males) of the other two species. Results
indicate that although differences in male and female isolation depend on the populations tested, the isolation behaviour
between a pair of species is highly correlated despite the variations. However, the rank order of the isolation level along
the populations was not correlated in both sexes, which suggests that different genes act in male and female sexual isolation.
Neither for males nor for females, the isolation behaviour of one species was paralleled in the other two species, which indicates
that the genetic systems involved in this trait are species-pair specific. The implications of these results are discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
Forty six soybean (Glycine max [L.] Merr.) varieties were evaluated for their vegetative response to a foliar application of abscisic acid, benzyladenine, or o-methoxyphenyl phosphinic acid (OMPA). Varietal responses to each chemical ranged from no effect to severe growth retardation. When the same varieties were evaluated for their response to water stress, the length of time required for severe wilting ranged from 48 h to 120 h. A cluster analysis was used to relate the coefficient of parentage of the varieties with their response to chemicals or water stress. The response of a variety to one of the chemicals did not predict the response to a different chemical. Further, the response of a variety to a chemical did not predict the response of a similar variety to the same chemical. The water stress rating was neither related to the chemical responses nor to the coefficient of parentage for the varieties in the test. The effects of night interruption and darkness were more pronounced on northern than on southern varieties, analogous with the pattern of reproductive regulation by photoperiod. 相似文献
17.
该文描述了甘肃东祁连山发现的豆科( Leguminosae)扁蓿豆属( Melilotoides)一新变种———天祝扁蓿豆(Melilotoides ruthenica var. tianhzhuensis C. L. Xu )。该变种植株节间(3~18 mm)短于原变种(30~65 mm);叶片小于原变种;小叶宽卵形或倒卵形;花冠外部(背部)和内部(腹部)均为黄色,且不带紫色和条纹。上述特征与原变种明显不同,易于区别。 相似文献
18.
Bacteriods isolated from protoplasts taken from Rhizobium japonicum induced root nodule of Glycine max L. showed complete viability when plated onto a conventional rhizobial growth medium supplemented with 0.2 M Mannitol. The same medium but without extra mannitol resulted in the absence of colony formation. The protoplast isolation method eliminated the possibility of contaminant bacteria from infection threads to be scored. The redifferentiated bacteroid clones have the same genetical characteristics as the orginal inoculum strain. This and other recent findings of bacteroid viability are discussed in the light of the existing belief that bacteroids are non-viable. 相似文献
19.
Yeast ARS function and nuclear matrix association coincide in a short sequence from the human HPRT locus 总被引:8,自引:0,他引:8
Robert C. Sykes Dong Lin Sung J. Hwang Paul E. Framson A. Craig Chinault 《Molecular & general genetics : MGG》1988,212(2):301-309
Summary A sequence that supports extrachromosomal replication of plasmids in yeast has been identified within the first intron of the human hypoxanthine-guanine phosphori bosyltransferase (HPRT) gene. This represents the first isolation of such an autonomously replicating sequence (ARS) from an exactly known position in the human genome. This ARS shares similarities of imparted yeast phenotype and DNA sequence with other heterologus ARSs. In addition, this sequence is found to be a matrix association region (MAR) on the basis of specific binding to nuclear matrices prepared from several mammalian cell types. It also exhibits anomalous electrophoretic behavior, characteristic of bent DNA, on polyacrylamide gels. The coincidence of these properties supports the possibility that this region may play a role in DNA replication within its normal chromosomal context. 相似文献
20.
Noel H. Holmgren 《Brittonia》2004,56(2):107-114
A closely related group of Great Basin endemic dradas,Draba cusickii O. E. Schulz,D. sphaeroides Payson, andD. pedicellata (Rollins & R. A. Price) Windham, are described, keyed, and discussed in order to putD. pedicellata var.wheelerensis N. H. Holmgren, var. nov. in perspective.Draba cusickii is endemic to Steens Mountain of southeastern Oregon, andD. sphaeroides is known only from three mountain ranges in Elko County, Nevada, whereasD. pedicellata is more widespread in mountain ranges of eastern Nevada in Elko, Eureka, Nye, and White Pine counties.Draba pedicellata var.pedicellata occupies most of the range of the species, with var.wheelerensis being restricted to the Snake Range, just to the east of the range of the typical variety. 相似文献