ISSN:0190-4167    

DOI:10.1080/01904167909362719

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The determination of the leaf nitrate concentration, as well as the nitrate reductase activity have been proposed as a parameters for the estimation of the nitrogen requirements of citrus plants. Because this, it is interesting to dispose of a well criteria for their suitable diagnosing. On nutritionally normal Verna lemon trees we study the annual evolution of the leaf nitrate levels as well as the nitrate reductase activities. At the same time, the cause of the nitrogen alterations induced by iron chlorosis are determined. The results show that is the ferredoxin the iron compound responsible of this nitrogen unbalance.

ISSN:0190-4167    

DOI:10.1080/01904167909362720

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The higher fatty acids (HFA) are important plant constituents that are implicated in the grass tetany hazard in livestock. A method is given whereby a technician can analyze 12 forage samples daily for HFA content.

ISSN:0190-4167    

DOI:10.1080/01904167909362721

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Spotty chlorosis appeared on the young leaves of Al toxic plants and was severe or high Al level. Stems of the Al‐treated plants were purple While the roots were short, thick and brown in colour with little branching.

ISSN:0190-4167    

DOI:10.1080/01904167909362722

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Physical, physiological and biochemical processes occurring during colonization, infection, and nodule development and maintenance phases of an effective legume‐rhizobia symtiotic nitrogen fixation system are discussed. Limited knowledge of host reactions to invasion by rhizobia which result in failure to establish a symbiotic nitrogen fixation system are related to more thoroughly researched reactions of resistant host plants to invastion by pathogenic organisms. The most common resistant host responses are an increase in the production of phenolic compounds and phenol oxidizing enzymes. Many of the pheolic compounds or their quinones produced by enzymatic oxidation inhibit the action cell wall degrading enzymes and phytohormones, are antibiotic toward pathogenic organisms, and are phytotoxic to host plant cells. It is postulated that similar host responses result with rhizobia invasion and that the magnitude of these responses determine specificity of legume‐rhizobia symbiosis.

ISSN:0190-4167    

DOI:10.1080/01904167909362723

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The present study was designed to study the effects of various concentrations (0.00; 0.01, 0.10 and 1.00‐mg/ml) of triacontanol on root, stem and leaf growth and polyphenol oxidase activity in each respective tissue; in Grand Rapids and Great Lakes varieties of eleven‐day‐old dark and light grown lettuce seedlings.

ISSN:0190-4167    

DOI:10.1080/01904167909362724

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Environmental effects on several CAM plants which bring them in CAM (when plants show diurnal fluctuations in the concn of titratable acid) and out of CAM (when acid concn remain low with no diurnal fluctuation) were studied. Change in photoperiod alone caused the greatest amplitude of the acid fluctuation from 2.6 to 2.7 meq acid/100 g FW inSedum telephoides. Light intensity affected the K/Ca ratio from a high when in CAM to a low when out of CAM in the 2 species. The plasma emission spectrograph analysis of the leaf tissue grown in the specific environment showed the presence of high levels of Mn, B, Cu, Zn, Na, Al and Si inSedum telephoides. The elemental analyses of CAM plants showed 1.8 to 9.4% K.

ISSN:0190-4167    

DOI:10.1080/01904167909362725

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Water potentials, osmotic potentials and stomatal resistances were measured daily in a growth chamber during a two‐week period, in growing leaves of a drought‐sensitive and a drought‐resistant winter wheat (Triticum aestivumL. em. Thell.), which had the roots maintained in nutrient culture media with 0.001 or 0.01MFeEDDHA. For both cultivars, the high level of FeEDDHA increased water potentials, turgor potentials, and stomatal resistances, and decreased osmotic potentials. Roots of plants grown with the high level of FeEDDHA had lower concentrations of Ca and K, and higher concentrations of Fe, than those grown with the low level. The results showed that the concentration of FeEDDHA used in plant‐water‐relation studies should be defined because the chelate affects the water balance of plants.

ISSN:0190-4167    

DOI:10.1080/01904167909362726

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904167909362718

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor