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101.
With the development of pineapple [Ananas comosus (L.) Merr.] as a fresh fruit crop, it became common to force inflorescence development with ethephon [(2-chloroethyl)phosphonic acid] or ethylene throughout the year. Environmental induction (EI) of inflorescence development disrupts scheduling of fruit harvest and may cause significant losses if small plants are induced, resulting in fruits that are too small to be marketable. Our objective was to identify plant growth regulators (PGRs) that could inhibit EI. Because circumstantial evidence indicates that EI occurs in response to naturally produced ethylene or changes in plant sensitivity to it, most work was done with PGRs that inhibit ethylene biosynthesis or block ethylene action. The synthetic auxin 2-(3-chlorophenoxy)propionic acid (CPA) was included because in one study it reduced the percentage of EI. GA3, aminooxyacetic acid (AOA), aminoethoxyvinylglycine (AVG), daminozide [butanedioic acid mono-(2,2-dimethylhydrazide)], and silver thiosulfate (STS) had no effect on EL CPA, paclobutrazol [(2RS,3RS)-1-(4-chlorophenyl)methyl-4,4-dimethyl-2(1h-1,2,4-triazol-1-yl)penten-3-ol], and uniconazole [(E)-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol] delayed or inhibited EI of pot-grown pineapple plants. Uniconazole and paclobutrazol inhibited growth and ethylene production by leaf basal-white tissue, and either or both effects could account for the inhibition of EI. Production of 1-aminocyclopropane-1-carboxylic acid (ACC) was unaffected by these compounds, but the activity of ACC oxidase, which converts ACC to ethylene, was inhibited and probably accounts for the reduced ethylene production by leaf basal-white tissue. CPA stimulated ethylene production by stem apical tissue approximately fourfold relative to the control. ACC oxidase activity and the malonyl-ACC (MACC) content in stem apical tissue were also greater than in the control, indicating that CPA greatly stimulated the production of ACC and its sequestration into MACC. The mechanism by which CPA delayed or inhibited EI is not known. CPA, paclobutrazol, and uniconazole appear to have some potential for inhibiting EI of pineapple. Their effect on yield needs to be determined.Abbreviations ACC oxidase
1-aminocyclopropane-1-carboxylic acid oxidase
- CPA
2-(3-chlorophenoxy)propionic acid
- AOA
aminooxyacetic acid
- AVG
aminoethoxyvinylglycine
- daminozide
butanedioic acid mono-(2,2-dimethylhydrazide)
- DM
dry mass
- ethephon
[(2-chloroethyl)phosphonic acid]
- FM
fresh mass
- GA
gibberellin
- EI
environmental induction of inflorescence development
- IA
inflorescence appearance
- LSD
Fisher's protected least significant difference
- MACC
malonyl-ACC
- NAA
naphthaleneacetic acid
- PGR
plant growth regulator
- paclobutrazol
(2RS,3RS)-1-(4-chlorophenyl)methyl-4,4-dimethyl-2-(1h-1,2,4-triazol-1-yl)penten-3-ol]
- uniconazole
(E)-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol
- STS
silver thiosulfate
- M-leaf
fourth leaf
- Ml-L
first leaf younger than M-leaf 相似文献
102.
103.
Assessment Battery Paul B. Gillooly Michael H. Smolensky Donna L. Albright Bartholomew Hsi David R. Thorne 《Chronobiology international》1990,7(2):143-153
-As part of a two clock-time (0830 versus 2030) evaluation of administration-time dependent effects of dexedrine (S mg) and triazolam (0.25 mg) on human cognitive performance, placebo (control) studies were conducted on 12 diurnally active (0700-2300) male adults (23-38 yrs) using a double-blind, randomized crossover design. Testing was conducted hourly during a series of sleepless 13-hr spans commencing in the morning or evening, using the Walter Reed computer controlled and scored multi-task cognitive performance assessment battery. For the placebo condition, Single and Group Cosinor analyses documented circadian rhythms in performance for most tasks (reaction time, logical reasoning, serial add/subtract and spatial orientation) both for individuals and the group. Overall, performance was worse overnight, when sleepiness was greatest, and best between 1830 and 2030. It was most variable around 0600-0700. The day-night variation in performance over all cognitive tests amounted to 21% of the 24-hr mean. 相似文献
104.
George A. Wistreich Max D. Lechtman Richard F. Baker J. W. Bartholomew 《Applied microbiology》1972,23(1):155-157
The applicability of a synthetic zeolite (type 4A, Union Carbide Corp., Linde Div., New York, N.Y.) as a disruptive agent in a procedure for the preparation of pure bacterial cell wall fractions from a variety of phenol-killed gram-negative, gram-positive, and acid-fast bacteria was demonstrated. The disruptive effect was found to be limited with formaldehyde-killed gram-positive cells and most gram-positive cocci killed either by phenol or formaldehyde. 相似文献
105.
106.
George Wistreich Max D. Lechtman J. W. Bartholomew R. F. Bils 《Applied microbiology》1968,16(9):1269-1275
The use of a synthetic zeolite (type 4A, Union Carbide Corp., Linde Div., New York, N.Y.) in a procedure for the preparation of pure cell wall fractions proved successful for many gram-positive, gram-negative, and acid-fast bacteria, as well as for some fungi. The technique, however, was found to be limited in effectiveness for Rhodospirillum rubrum, Gaffkya tetragena, and Sarcina lutea, and not applicable to preparations of heat killed microorganisms. The possible mechanisms of zeolite action, together with the effect of the disruptive procedure on the chemical composition of cell wall fragments, were investigated also. 相似文献
107.
108.
Dyes of all major types were tested for their suitability as the primary dye in the Gram stain. When a counterstain was not used, some dyes of all types were found to differentiate Gram-positive from Gram-negative organisms. When a counterstain was used, these dyes were found to vary greatly in their suitability. Those dyes found to be good substitutes for crystal violet were: Brilliant green, malachite green, basic fuchsin, ethyl violet, Hoffmann's violet, methyl violet B, and Victoria blue R. All are basic triphenylmethane dyes. Acid dyes were generally not suitable. Differences in the reaction of Gram-positive and Gram-negative cells to Gram staining without the use of iodine were observed and discussed but a practical differentiation could not be achieved in this manner. Certain broad aspects of the chemical mechanism of dyes in the gram stain are discussed. 相似文献
109.
Bartholomew, J. W. (University of Southern California, Los Angeles), and Thomas Cromwell. Relative contribution of the cell wall, cytoplasmic membrane, and cytoplasm to the gram-positive characteristic of Bacillus megaterium. J. Bacteriol. 90:643-647. 1965.-A comparison of the roles of the cell wall, cytoplasmic membrane, and cytoplasmic components revealed that the intact cell wall was the dominant contributor to the gram-positive state. Protoplasts of Bacillus megaterium were confirmed as being gram-negative, as reported by Gerhardt et al. The "gram-positive protoplast" report of Amano et al. was shown to be a laboratory-produced artifact, resulting from the comparison of smears made from saline suspensions of Escherichia coli cells with smears made from formalin-sucrose suspensions of B. megaterium protoplasts. 相似文献