Effects of growth-regulating substances on fungi

1969 ◽  
Vol 15 (7) ◽  
pp. 713-721 ◽  
Author(s):  
K. M. Leelavathy

The effects of four growth-regulating substances, viz. indole acetic acid, gibberellic acid, 2, 4-dichlorophenoxy acetic acid, and naphthalene acetic acid on the linear growth of Penicillium herquei, Fusarium nivale, Thielavia terricola, and Cunninghamella echinulata were studied. Gibberellic acid at 400 p.p.m. did not reduce fungal growth, whereas the remaining substances at this rate inhibited fungal growth completely. Certain concentrations of the latter substances reduced while others had no influence on growth rate. Gibberellic acid at 1 and 5 p.p.m. was the only substance causing some stimulation of Fusarium nivale. Neither this stimulation nor the inhibition in other cases was constant with regard to growth-regulating substances and fungal species. In general, low concentrations of the growth-regulating substances had no effect on the growth of any of the fungi tested while high concentrations mostly inhibited growth to various extents.

Weed Science ◽  
1972 ◽  
Vol 20 (5) ◽  
pp. 506-510 ◽  
Author(s):  
R. E. Phillips ◽  
D. B. Egli ◽  
L. Thompson

The total quantity and concentration of six herbicides, isopropylm-chlorocarbanilate (chlorpropham), 2-chloro-4-(ethylamino)-6-(isopropylamino-s-triazine (atrazine), 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron), 2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide (alachlor), 3-amino-2,5-dichlorobenzoic acid (chloramben), and (2,4-dichlorophenoxy)acetic acid (2,4-D), in unaerated, aqueous solutions absorbed by seeds of 11 soybean(Glycine max(L.) Merr.) strains were measured. Mechanism of movement of the herbicides from the aqueous solutions to the seeds in the experimental procedure employed was diffusion. Total quantity and concentration of herbicide found in the seeds differed significantly for both herbicides and soybean strains. Total quantity of herbicide absorbed was determined by total oil and percent oil of the seeds. The capacity of the seeds to absorb a given herbicide was more closely related to percent oil of the seeds than to total oil of the seeds. The emergence and seedling shoot weight of ‘Cutler’ soybeans were not affected appreciably by concentrations of linuron, atrazine, and chloramben (potassium salt) but were reduced by high concentrations of chlorpropham and alachlor and relatively low concentrations of 2,4-D (potassium salt) in the seeds.


Weed Science ◽  
1974 ◽  
Vol 22 (3) ◽  
pp. 285-292 ◽  
Author(s):  
J. R. Diem ◽  
D. E. Davis

Nontoxic concentrations of 2,4-D [(2,4-dichlorophenoxy)acetic acid] increased the toxicity of ametryne [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine], when applied to the roots of waterhyacinth [Eichornia crassipes(Mart.) Solms], when applied to the roots or foliage of corn (Zea maysL.), and to a lesser extent, when applied to the roots of soybean [Glycine max(L.) Merr.]. Nontoxic concentrations of 2,4-D frequently also increased the absorption of ametryne, water, and radioactive calcium by all three species. Mixtures containing toxic concentrations of 2,4-D with ametryne were not synergistic and sometimes the mixtures were less toxic than ametryne alone. Toxic concentrations of 2,4-D also decreased plant dry weight and the absorption of ametryne, water, and calcium. Low concentrations of ametryne increased the absorption of water and sometimes calcium while high concentrations decreased dry weight and the absorption of water and calcium.


2009 ◽  
Vol 36 (No. 4) ◽  
pp. 140-146 ◽  
Author(s):  
J.K. Kanwar ◽  
S. Kumar

The influence of growth regulators, explants and their interactions on in vitro shoot bud formation from callus was studied in <I>Dianthus caryophyllus</I> L. The leaf and internode explants were cultured on Murashige and Skoog (MS) medium containing different concentrations of growth regulators. The highest callus induction was observed with 2 mg/l 2,4-dichlorophenoxy acetic acid (2,4-D) and 1 mg/l benzyl adenine (BA). Out of twenty seven shoot regeneration media tested, only 2 mg/l thidiazuron (TDZ) and zeatin alone or in combination with naphthalene acetic acid (NAA) and/or indole acetic acid (IAA) could differentiate calli. The highest average number of shoots was observed with 2 mg/l TDZ and 1 mg/l IAA. Significant differences were observed in calli producing shoots and number of shoots per callus in the explants of leaf and internode. The shoots were elongated and multiplied on MS medium supplemented with 1 mg/l BA and solidified with 1% agar. The shoots were rooted and hardened with 76% survival success in pots after six weeks of transfer to the pots.


1970 ◽  
Vol 33 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Sridhar Gutam ◽  
Virendra Nath ◽  
GC Srivastava

A pot experiment was conducted in the rabi (post rainy) seasons of 2001 and 2002 to study the genotypic differences in grain growth rate and endogenous hormonal content in the developing grains of hexaploid and tetraploid wheat. The endogenous hormonal contents of grains in both the ploidy levels had changed in sequence. At 5 days after anthesis (DAA), gibberellic acid (GA3); at 15 DAA (rapid growth phase), indole-acetic acid (IAA); at 25 DAA (dough stage), abscisic acid (ABA) were maximum. At 35 DAA, all the endogenous hormonal level decreased and among the hormones, ABA was highest followed by IAA and GA3. Hexaploids recorded higher concentrations of endogenous hormones (13.38% IAA, 17.89% GA3, and 14.7% ABA) on fresh weight basis and resulted in higher seed weight (56.99 mg/grain) and grain growth rate (0.009 g/g/day) compared to tetraploids (49.08 mg/grain; 0.008 g/g/day) on dry weight basis by better mobilization of photosynthates during grain filling. Key Words: Grain growth rate, hormones, indole-acetic acid, gibberellic acid, abscisic acid. doi:10.3329/bjar.v33i3.1608 Bangladesh J. Agril. Res. 33(3) : 493-502, September 2008


1977 ◽  
Vol 89 (1) ◽  
pp. 235-238 ◽  
Author(s):  
P. E. Russell ◽  
A. E. A. Mussa

SummaryTwo systemic fungicides, benomyl and thiabendazole, were more active than the non-systemic fungicide Drazoxolon in inhibiting fungal growth in vitro. A similar pattern was obtained in glasshouse trials with benomyl and thiabendazole giving adequate protection at low concentrations while Drazoxolon was ineffective unless applied at 50% the commercial product concentration. A field trial using thiabendazole, Drazoxolon and a mixture of benomyl and thiram confirmed the glasshouse results.Some phytotoxicity was noticed with high concentrations of both benomyl and thiabendazole, but satisfactory disease control was achieved using fungicide concentrations which did not induce phytotoxicity.


2015 ◽  
Vol 44 ◽  
pp. 38-44 ◽  
Author(s):  
H. Sandhya ◽  
Rao Srinath

Suitable protocol for induction of callus and regeneration was developed from different explants viz., node, stem and leaves in Physalis minima. MS basal medium supplemented with various concentrations (1.0-4.0mg/l) of auxins like 2,4-Dichlorophenoxy acetic acid (2,4-D), α-naphthalene acetic acid (NAA) and Indole-3-acetic acid (IAA) and cytokinins (0.5-1.5mg/l) like BAP or Kn were used. All the three explants responded for induction of callus, however stem explants were found superior, followed by node and leaf. Callus induction was observed in all the auxins and combination of growth regulators used with varied mass (2010±1.10) and highest percentage of callus induction was observed from stem at 2.0mg/l 2,4-D (90%) followed by NAA (70%) and IAA (50%). Organogenesis was induced when nodal explants were transferred on MS medium supplemented with 2,4-D and Kn at various concentrations, maximum being on 2.0mg/l 2,4-D + 1.0mg/l Kn (90%). Regenerated shoots were elongated on 0.5mg/l GA3. The shoots were subsequently rooted on MS + 1.0mg/l IBA (95%) medium. Rooted shoots were hardened and acclimatized, later they were transferred to polycups containing soil, cocopeat and sand in the ratio 1:2:1.Keywords:Physalis minima, Node, Stem, Leaf, callus and growth regulators.


1987 ◽  
Vol 50 (12) ◽  
pp. 1044-1047 ◽  
Author(s):  
R. S. FARAG ◽  
M. A. EL-LEITHY ◽  
A. E. BASYONY ◽  
Z. Y. DAW

The effect of some widely used plant hormones (indol-3-acetic acid and gibberellic acid), herbicides (gramoxone, stomp and treflan) and insecticides (malathion, actellic and guthion) on Aspergillus parasiticus growth and aflatoxin production in a synthetic medium was studied. Addition of indol acetic acid to the medium increased aflatoxin production more than gibberellic acid. Treflan at 5, 10 and 20 ppm levels caused a highly significant stimulatory effect on A. parasiticus growth and aflatoxin production. In contrast, stomp at 10 and 20 ppm produced the reverse effect. Guthion, an insecticide, caused a marked decrease in fungal growth and aflatoxin production. The inhibitory effect of insecticides under study on both fungal growth and aflatoxin production in effectiveness followed the sequence: guthion&gt;actellic&gt;malathion. At the recommended application rate (10 ppm), with the exception of indol acetic acid and treflan, all compounds suppressed mold growth and aflatoxin production.


1984 ◽  
Vol 179 (1-2) ◽  
pp. 123-128 ◽  
Author(s):  
K.K. Chattopadhyay ◽  
R.N. Bhattacharyya ◽  
P.S. Basu

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