摘要:

The following new species and combinations are proposed:Albertiniella polyporicola(Jaczevski) comb. nov.,Emericella aurantiobrunnea(Atkins, Hindson and Russell) comb, nov.,E. fruticulosa(Raper and Fennell) comb. nov.,E. heterothallica(Kwon, Raper and Fennell) comb. nov.,E. parvithecia(Raper and Fennell) comb. nov.,E. striata(Rai, Tewari and Mukerji) comb. nov.,E. unguissp. nov.,E. violacea(Fennell and Raper) comb. nov.,Eupenicillium mollesp. nov.,Eurotium carnoyisp. nov.,E. cristatum(Raper and Fennell) comb. nov.,E. chevalierivar.intermedium(Thom and Raper) comb. nov.,E. montevidense(Talice and MacKinnon) comb. nov.,E. niveo-glaucum(Thom and Raper) comb. nov.,E. pseudoglaucum(Blochwitz) comb. nov.,E. umbrosum(Bainier and Sartory) comb. nov.,Microthecium inordinatumsp. nov.,Petriellidium angustumsp. nov.,Phaeotrichum benjaminiisp. nov.,P. cylindrosporumsp. nov.,Preussia cylindricasp. nov.,Preussia indicavar.oryzetorum(Montemartini) comb. nov.,Roumegueriella rufula(Berk. and Br.) comb. nov.,Thielavia albomyces(Cooney and Emerson) comb. nov.,T. terrestris(Apinis) comb. nov.,Tripterosporella Pakistani(Mirza) comb. nov.,Zopfia biturbinata(Dur. and Mont.) comb. nov.,Z. duplicispora(Janse) comb. nov.

ISSN:0008-4026    

DOI:10.1139/b72-011

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Hieracium floribundumis a rosette species requiring a number of long days for flower induction. Histological studies of vegetative, transition, and floral apices showed the structural changes associated with flower induction in this species. One striking histochemical change observed was the absence of starch in vegetative apices and the accumulation and retention of quantities of starch in prefloral and floral apices. A study of initiation and development of axillary buds at the time of flowering revealed that there was a gradient in the potential to flower shown by these buds along the developing flower stalk to the base of the plant. The buds in the axils of upper peduncle bracts always develop as capitula while the apices of the buds in the axils of the next few bracts assume the shape of floral buds but fail to develop unless the upper developing inflorescences are removed. Buds in the axils of the lowest bracts and upper (youngest) leaves have the potential to form rosettes, stolons, or inflorescences depending on the environmental conditions in which the plants are grown. Buds formed in the lower (oldest) leaf axils normally fail to grow out until after seed set when a few may develop as rosettes. Possible explanations for these results are discussed, and some experimental approaches being used to elucidate the physiological basis for bud expression are indicated.

ISSN:0008-4026    

DOI:10.1139/b72-012

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Saxifraga ferruginearanges over that part of northwestern North America which was glaciated in late Pleistocene time. A survey of chromosome numbers within the species places diploids south of the ice margin and, in a few locations, inside the margin. Elsewhere only polyploids have been found. The distribution of diploids and polyploids supports the reality of refugia on Kodiak Island and the Queen Charlotte Islands.It is proposed that polyploids evolved either before or during recession of the ice and that they rather than the diploids were the colonizers of the newly open disturbed terrain.

ISSN:0008-4026    

DOI:10.1139/b72-013

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

As early growth is exponential it was measured as the pseudo-first-order rate coefficient,k1′. The growth coefficient is independent of the method of measurement, so different values derived from different measurements such as dry weight, fresh weight, chlorophyll content, and area reflected somewhat different aspects of growth in a given organ. At low light intensityk1′ was highest for lamina dry weight and lowest for root dry weight, and at high light intensity, highest and lowestk1′.were obtained for "stem" dry weight and lamina area, respectively. The differences in rate coefficients between organs were less than 10% of their values at high light intensity. The rectangular hyperbolic fit of the dependence ofk1′ on light intensity was used to compute a maximum value (kmL) independent of light intensity. AkmLof 0.34 per day was obtained for plants of Marquis wheat grown at 25 °C with Hoagland's solution in Went's medium under controlled environment, and the highest value, 0.37, was achieved by dry weight of "stems." A complex form parameter was also computed, and it included a function of the efficiency of light use for growth, which was highest for leaf area and lowest for root dry weight. Measurements on complete morphological entities such as whole organs are best interpreted. Growth kinetics and its relationship to "growth analysis" were discussed in distinct favor of the former approach. The growth coefficient as the relative growth rate has been abused and that term should be dropped. The prospects of kinetic or primary analysis as the standard quantitative method are great, as initially envisaged by V. H. Blackman half a century ago.

ISSN:0008-4026    

DOI:10.1139/b72-014

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Tissue cultures of tobacco grown for 12 weeks in contact with lunar material returned by Apollo 12 contained 21 to 35% more total pigment than control tissues. This difference is due primarily to increased chlorophyllaconcentrations per gram fresh weight of tissue in experimental cultures. No differences were noted in the fresh or dry weight of the experimental and control cultures.

ISSN:0008-4026    

DOI:10.1139/b72-015

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The effect of pretreatments given to wheat grains which are supposed to increase drought resistance was studied in young plants under controlled conditions of water stress. In one of the two cultivars used, root growth was found to be significantly greater in plants from pretreated seeds, during and after a period of water stress.Under conditions of ample water availability, root growth was not influenced by the pretreatments.

ISSN:0008-4026    

DOI:10.1139/b72-016

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The map of chromosome 2 has been brought up to date and 33 genes are located. Three-point crosses indicate that the gene order iss ms10wv Wo Me o dil aw(v2op suf)p d m dv, with the relative order of the three genes in parentheses still to be determined. Multiple two-point crosses are reported for the other 18 genes whose linkage relationships tod, aw, and their nearest neighbor are discussed. This permits the construction of a map for these genes placing the 33 mutants in relation to the centromere. The geneddseems to be wrongly located.The heterogeneity of some recombination values and the paucity of close linkages in the central portion of the chromosome reveal a number of problems which should be investigated. The chromosome map which has been largely constructed from material with a uniform background forms a reference point for investigating the effect of asynapsis and inversions.

ISSN:0008-4026    

DOI:10.1139/b72-017

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

This paper describes the establishment and validation of 14 groupings of cultivars in the hexaploid cultivated oats. This study is based on 5000 samples from various parts of the world. In order to base the groupings on non-agronomic characters, 21 attributes, mainly micromorphological ones taken from floral parts such as lemmas, paleas, and lodicules, were examined and recorded. A divisive chain algorithm was devised for clustering 5000 individuals. The 107 clusters thus formed were then processed by single linkage, yielding 14 acceptable groupings; these were subsequently investigated by a canonical analysis. The procedural principles proposed are described and discussed.

ISSN:0008-4026    

DOI:10.1139/b72-018

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Using analysis of variance, four sequentially obtained characters were chosen from 21 to discriminate among 14 groupings (demes) proposed elsewhere. The 14 estimated sets of 36 multinomial probabilities obtained therefrom, together with the estimated probability of occurrence of each deme, were used to construct a Bayesian identification procedure. Computer simulation of identification suggested that 50 plants are sufficient for identification. The merits of Bayesian identification schemes for infraspecific categories are described.

ISSN:0008-4026    

DOI:10.1139/b72-019

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Decapitated 5-mm segments from stage 1 sporangiophores ofPhycomyces blakesleeanushad similar regeneration capacity and polarity under room as under constant conditions. Regeneration on segments with whole apices was more frequent under room conditions despite resumption of apical elongation, but was only about half as frequent as on decapitated apical segments. Regeneration at incisions in the middle of stage 1 sporangiophores was rare unless cross walls formed at the incision. Sporangiophore halves and pairs of 5-mm segments were grafted successfully and cultured for 24 h. The protoplasts fused and a new wall rejoined the cut ends. Regeneration was rare on grafted sporangiophore halves. On grafts of decapitated, oppositely oriented segments regeneration was almost 100% and occurred mainly at the apical ends alone whether these were fused or free. On grafts of decapitated, normally oriented segments in normal or reversed order almost all anterior segments regenerated apically (as did the controls), but only half or fewer of the same segments in posterior position regenerated. Multiple regeneration and attainment of stage 4 were more frequent on anterior segments. Regeneration was less than 50% on grafts between segments with whole apices and basal segments, and on the latter was much less than on isolated controls.Movement of cytoplasm detectable by dry weight changes only occurred towards the regenerating end of segments after initiation of sporangiophores. The velocity of bidirectional protoplasmic streaming in segments increased during regeneration and was highest towards the basal non-regenerating end.The results of grafting do not support the hypothesis that an inhibitor from the apex normally suppresses regeneration (branching), but both suppression and induction of regeneration can be explained by a mechanism based on acropetal transport.

ISSN:0008-4026    

DOI:10.1139/b72-020

出版商:NRC Research Press    

年代:1972

数据来源: NRC