摘要:

not available

ISSN:1923-4287    

DOI:10.1139/cjr40c-049

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

The protoplasm of hardy and non-hardy cells was compared with regard to displacement by centrifuging, rounding-up time on plasmolysis, deplasmolysis injury, rate of Brownian movement, resistance to and recovery from distortion by micromanipulation. The conclusions are: (i) When the cells are in the normally hydrated (i.e., turgid) condition there is either no difference in the consistency of hardy and non-hardy protoplasm, or else it is slightly less m the latter; (ii) when the cells are plasmolysed to the same degree (i.e., with a weaker plasmolyte in the case of the non-hardy) there is no difference in consistency; (iii) when the cells are in equilibrium with one and the same concentration of plasmolyte, the protoplasmal consistency of the non-hardy is greater than that of the hardy; (iv) the non-hardy are more susceptible to mechanical injury.

ISSN:1923-4287    

DOI:10.1139/cjr40c-050

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Random isolates ofPenicillium,Actinomyces, and certain miscellaneous soil-inhabiting fungi were tested in steam sterilized soil, under pure culture conditions, for their association effects on the virulence ofHelminthosporium sativumP. K. and B. on wheat seedlings. Certain isolates of the first two genera mentioned exerted a marked degree of suppression, some had no effect, while others increased the virulence. Similarly, these effects varied widely within certain species ofPenicillium. This preliminary study indicates that the random isolates of many genera and species of fungi may differ widely in ability to affect the virulence of certain plant pathogens.

ISSN:1923-4287    

DOI:10.1139/cjr40c-051

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Dormant Norway spruce cuttings were collected in mid-November and treated with talc dusts containing two separate phytohormone chemicals, indolylacetic and naphthylacetic acids, in three concentrations, 0, 1000, and 5000 p.p.m., alone, and in combination with cane sugar and an organic mercurial disinfectant. Treated cuttings were planted immediately in outside frames in sand and a mixture of sand and peat in equal proportions. They were removed for examination 10 months later. Phytohormone treatment, except with the 5000 p.p.m. concentration of naphthylacetic acid, which was injurious, increased the number of cuttings rooted, the number and length of roots, the number of surviving cuttings, and the number of rooted cuttings with new growth. There were also marked effects on the initiation and development of new growth. The admixture of peat in the propagation medium improved rooting and development of new growth, particularly in certain of the phytohormone treatments. Only about 50% of the controls rooted in both sand and sand-peat, while the 5000 p.p.m. concentration of indolylacetic acid effected 68% rooting in sand and 82% in sand-peat.Both cane sugar and organic mercury significantly affected a number of the responses. However, the effects were comparatively small and depended, for the most part, on interactions with phytohormone treatments and media. Organic mercury increased the number of cuttings rooted by about 6%.

ISSN:1923-4287    

DOI:10.1139/cjr40c-052

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

In order to determine readily the usefulness of heterosis as an indicator of the yielding capacity of cereal crosses, replicated half rod row yield trials were made with bulk unselected seed of ten wheat crosses inF2and of six inF3. The practical yielding value of the latter six crosses was ascertained later by replicated rod row yield tests of selected lines inF6,F7andF8. All theF2populations (excepting aT.vulgare×T.persicumcross) yielded significantly more than the mean of the parental varieties, the increased yield being 52 and 64% for two of the crosses. Of the sixF3populations tested, the only one to yield significantly above the parental average was Reward × Hope, and the only ones to yield significantly less than the parental average were the two having Quality as one parent. Replicated plot tests of purified lines selected for high yield and other agronomic virtues showed the Reward-Hope combination to be particularly valuable, whereas the two crosses containing Quality were unpromising. The results suggest that replicated bulkF2tests may be used to indicate the yielding potentialities of wheat crosses, and that bulkF3tests may have supplementary value in this regard.

ISSN:1923-4287    

DOI:10.1139/cjr40c-053

出版商:NRC Research Press    

年代:1940

数据来源: NRC