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Action of Growth Retardants on the Seed Germination and EarlySeedling Growth in Leptadenia pyrotechnica (Forsk .) Decne
T t
Biochem. Physiol. Pflanzen (BPP), Bd. 162, S. 489 -494 (1971) Botany Department, University of Jodhpur, Jodhpur (India)
Action of Growth Retardants on the Seed Germination and Early Seedling Growth in Leptadenia pyrotechnica (FORSK.) DECNE. By D. N. SEN and D. D. CHAWAN With 6 figures (Received JliIay 5, 1971)
Summary Action of the three growth retardants (eee, B995 and SK & F 7997-A3) has been studied on the seed germination and early seedling growth in L. pyrotechnica. All the three chemicals slowed down the pace of seed germination and suppressed the same in higher concentrations, with the exception of SK & F 7997-A3 which caused only a germinated delay. The effect of these retardants on early seedling growth was also inhibitory. Only eee at lower concentrations enhanced the radicle elongation. The inhibitory effect was more pronounced on the hypocotyl as compared to the radicle.
Introduction
CCC or Cycocel or (2-chloroethyl) trimethylammonium chloride and B995 or N-dimethylaminosuccinamic acid are reported to be strong plant growth retardants and have a broad range of effects on the physiological and morphological behaviour of plant (CATHEY 1964). SK & F 7997-A3 or Tris-(2-diethylaminoethyl)-phosphate trihydrochloride to be included in the growing list of growth retardants (THOMAS and ANDERSON 1966). These regulants have been used in horticulture to produce more compact and bedding plants (CATHEY and STUART 1961; BOSE and HORE 1967). ZEEVAART (1964) and WITTWER and TOLBERT (1960) showed that CCC reduces internode length and therefore decreases plant height and that its primary effect is an inhibition of cell division. THOMAS (1964) observed suppression of fruiting branches, inhibition of flowering and reduction in yield of seed cotton by CCC. GASPER and LACOPPE (1968) noted an inhibition of growth due to the effect of CCC in barley seedlings. VED PRAKASH and LAL (1968) reported that germination of cotton seeds were stimulated in very low concentrations of CCC solution. The seeds treated with CCC produced stunted seedlings due to shortening of internodes. Cotyledonary, primary and mature leaves were found to be thick and dark green in colour. Material and methods
eee
Seeds of L. pyrotechnica were germinated in solutions of different concentrations of B 995 , and SK & F 7997-A3 and the controls in distilled water. A set of petridishes with 50 seeds
490
D. N.
SEN
and D. D.
CHAWAN
in each was placed at 30± 0 2C under 1000 lux illumination from white flourescent tubelights. Each set of experiment was replicated thrice and each replicate consisted of three petridishes. The criterion of germination was visual detection of radicle protrusion. The measurements of radicle and hypocotyl were recorded at the end of the tenth day and the results have been incorporated statistically.
Results
Germination The germination percentage for five days differed in different concentrations of the three growth retardants used here. The pace of germination in each of the three chemicals has been presented in figures 1, 2 and 3 respectively. The pace of seed germination was always slowed down with the increasing concentrations of the three retardants used. In case of B995 a cent percent germination could be observed only in 10 ppm solution at the end of the third day. The germinations and the onset of germination was delayed by one day in 1000 ppm solution of B995 (fig. 1). In case of eee a cent percent germination could be observed in 10 and 100 ppm solutions at the end of third and fourth days, respectively. However, a cent percent germination could not be observed in 500 and 1000 ppm concentration of eee during the five days duration (fig. 2). The effect of SK & F 7997-A3 appeared to be delaying the onset of germination with increasing concentrations of the chemical. In 5 and 10 ppm concentrations a
o
10 100 .500 CONe. OF B995 IN PPI1
Fig. 1. Effect of different concentration of of L. pyrotechnica.
B995
!OOO
on the pace of germination percentage in seeds
Action of Growth Retardants on the Seed Germination etc.
491
cent percent germination was completed within three days. The onset of germination was delayed by one day in 25 ppm and by two days in 50 ppm solutions. However, a cent percent germination could not be achieved in 50 ppm solution during the observation period (fig. 3).
o
10
CONe.
or
100 ,)00 CCC IN ppl'f
/000
Fig. 2. Effect of different concentrations of CCC on the pace of germination percentage in seeds of L. pyrotechnica.
700 -
o-
723 .. 5
1231,5
o ({}NC.
or
DAYS .) 10 25 SO Sf( I r 7997 - /13 IN ppl'f
Fig. 3. Effect of different concentrations of SK & F 7997-A3 on the pace of germination percentage in seeds of L. pyrotechnica.
492
D. N. SEN and D. D. eHAWAN
Growth of seedlings After germination the seedlings were kept as such in different solutions of the three growth retardants. The linear growth of the hypocot yl and radicle was measured at the end of the tenth day. The results are presented in figures 4, 5 and 6. The results presented in the above figures clearly indicate the growth inhibiting ability of of these retardants. A 10 ppm solution of eee slightly enhanced the radicle elongation. In concentrations higher than 10 ppm the growth of seedlings continued to decline till the higher concentration became inhibitory for growth completely. However, eee has not been found to be as drastically suppressing the growth of seedlings as B995 in 500 and 1000 ppm concentrations, SK & F 7997-A3 also inhibited the radicle and hypocotyl growth. The supression of linear growth was found to be more in radicle as compared to the hypocotyl. This inhibition was directly proportional to the concentrations of growth retardants. 100 -
80 -
o IIYPOCOTYL • fiAOICLE
12 50 12 ~
2::(!) ~
"
80 -
~ ~
~
'>..
;t:: W-
~
"
20 -
o-
0
10
700 .f00 7000
CONe OF 8$95 IN PPI1
o ffYPOCDTYL • RADICLE
~ ti~ E::
50 -
i:::: fO<.::>
fO -
80 -
o ffYPOeOTYL • RADICLE
f..;:
~ ~
20 -
D-
0
10
100 .f00 7000
eONC OF eee IN PPI1
20-
0-
0
.f
10
2S
so
[ONe. OF Sf("F 7991-AJ IN,P,P11
4 5 7 Fig. 4. Effect of different concentrations of B9% on the linear growth of radicle and hypoeotyl in ten days old seedlings of L. pyrotechnica.
Fig. 5. Effect of different concentrations of eee on the linear growth of radicle and hypocotyl in ten days old seedlings of L. pyrotcchnica. Fig. 6. Effect of different concentration of SK & F 7997-A3 on the linear growth of radicle and hypocotyl in ten days old seedlings of L. pyrotechnica.
Discussion
The metabolic pathway in germinating seeds appear to be regulated by many growth regulators. A large number of growth substances have been known to enhance or inhibit seed germination and seedling growth. The growth retardants have been used for inducing flower formation in some woody perennials (STUART 1961), to
1
Action of Growth Retardants on the Seed Germination etc.
493
prevent lodging in wheat (JUNG and STURM 1964) and in the formation of dwarf and bushy plantes in Bougainvillea (BOSE and HORE 1967). VED PRAKASH and LAL (1968) reported that germination of cotton seeds was stimulated in 0.05 percent eee solution. The seeds treated with eee produced stunted seedlings due to shortening of internodes. GASPER and LACOPPE (1968) noted an inhibition of growth due to the effect of eee in barley seedlings. SK & F 7997-A3 has been reported to be a strong retardant for the seedling growth of Lycopersicon esculentum MILL. var. SIOUX. (eHAWAN and SEN 1971b). The inhibiting action of SK & F 7997-A3 was reversed by gibberellin-A 3 on the seedling growth of Leptadenia pyrotechnica (eHAWAN and SEN 1971 a). In the present work, the effect of some growth retardants were studied on the quick germinating seeds of L. pyrotechnica (SEN 1968). B995 and eee slowed down the pace of germination. However, they suppressed the total germination in the higher concentrations. SK & F 7997-A3 caused delay in the germination process in higher concentrations only. The effect on the growth of radicle and hypocotyl was inhibitory with different concentrations of growth retardants. eee at lower concentrations enhanced the radicle elongation. However, the inhibitory effect was more pronounced on the hypocotyl elongation as compared to the radicle.
Acknowledgements Thanks are due to Head of the Botany Department, University of Jodhpur, for facilities and Dr. K. D. SHARMA for help in various ways. Free gift samples from Uniroyal chemicals, USA (B995); Cyanamid India Ltd. (CCC), and Smith Kleine & French Labs., UK (SK & F 7997A3) are greatfully acknowledged.
Literature BOSE, T. K., and HORE, B. K., Effect of growth retardants on some varieties of Bougainvilleas. Sci. and Cult. 33, 379 -380 (1967). CATHEY, H. M., Physiology of growth retarding compounds. Ann. Rev. PI. Physiol. Hi, 271-302 (1964). - and STUART, N. W., Comparative plant growth retarding activity of AMO-1618, Phosfon-D. Bot. Gaz. 123, 51-57 (1961). CHAWAN, D. D., and SEN, D. N., Tris-(2-diethylaminoethyl)-phosphate trihydrochloride and Gibberellin-A3 interaction in seedling growth of Leptadenia pyrotechnica (Forsk.) Decne Biochem. Physiol. 162, 108 -109 (1971 a). Inhibition of seedling growth of Lycopersicon esculentum Mill. var. Sioux. by Tris-(2-diethyl aminoethyl)-phosphate trihydrochloride - A growth retardant. Labdev. (in press) (1971 b). GASPER, '1'., and LACOPPE, J., The effect of CCC and AMO-1618 on growth, calalase, peroxidase and indole acetic acid oxidase activity If young barley seedings. Physiol. Plant. 21, 1104-1109 (1968).
494
D. N. SEN and D. D. CHAWAN, Action of Growth Retardants on the Seed Germination etc.
JUNG, J. VON, and STRUM, R., Wachstumsregulierende Wirkung von Chlorcholin chlorid (CCC). Landw. Forsch. 17, 1-19 (1964). SEN, D. N., Ecology of desert plants and observations on their seedlings. II. Germination behaviour of seeds in Asclepiadaceae. Osterr. Bot. Zeit. lUi, 18-27 (1968). STUART, N. W., Initiation of flower buds in Rhododendron after application of growth retardants. Science 134, 50-52 (1961). THOMAS, R. 0., Effect of application, timing and concentration of (2-chloroethyl) trimethyl ammonium chloride on plants size and fruiting responses of cotton. Crop. Sci. 4, 403 -406 (1964). THOMAS, C. M., and ANDERSON, J. D., Inhibition of the growth of peas by Tris-(2-diethylaminoethyl)-phosphate trihydrochloride. Plant Physiol. 41, 238-243 (1966). VED PRAKASH, and LAL, R. K., Effect of seed treatment with CCC, B995, gibberellic acid and kinetin on morphological and biochemical changes in cotton. Indian .Jour. Expt. BioI. 6, 44-46 (1968). WITTWER, S. R., and TOLBERT, N. E., (2-chloroethyl)-trimethyl ammonium chloride and related compounds as plant growth and flowering of the tomato. Amer. Jour. Bot. 47,560-565 (1960). ZEEVAART, J. A. D., Effect of the growth retardant CCC on the floral initiation and growth in Pharbitis nil. Plant. Physiol. 39, 402-408 (1964). Authors' address: Dr. D. N. SEN and Dr. D. D. CHAWAN, Botany Department University of Jodhpur, Jodhpur (India).
Biochem. Physiol. Pflanzen (BPP), Bd. 162, S. 489 -494 (1971) Botany Department, University of Jodhpur, Jodhpur (India)
Action of Growth Retardants on the Seed Germination and Early Seedling Growth in Leptadenia pyrotechnica (FORSK.) DECNE. By D. N. SEN and D. D. CHAWAN With 6 figures (Received JliIay 5, 1971)
Summary Action of the three growth retardants (eee, B995 and SK & F 7997-A3) has been studied on the seed germination and early seedling growth in L. pyrotechnica. All the three chemicals slowed down the pace of seed germination and suppressed the same in higher concentrations, with the exception of SK & F 7997-A3 which caused only a germinated delay. The effect of these retardants on early seedling growth was also inhibitory. Only eee at lower concentrations enhanced the radicle elongation. The inhibitory effect was more pronounced on the hypocotyl as compared to the radicle.
Introduction
CCC or Cycocel or (2-chloroethyl) trimethylammonium chloride and B995 or N-dimethylaminosuccinamic acid are reported to be strong plant growth retardants and have a broad range of effects on the physiological and morphological behaviour of plant (CATHEY 1964). SK & F 7997-A3 or Tris-(2-diethylaminoethyl)-phosphate trihydrochloride to be included in the growing list of growth retardants (THOMAS and ANDERSON 1966). These regulants have been used in horticulture to produce more compact and bedding plants (CATHEY and STUART 1961; BOSE and HORE 1967). ZEEVAART (1964) and WITTWER and TOLBERT (1960) showed that CCC reduces internode length and therefore decreases plant height and that its primary effect is an inhibition of cell division. THOMAS (1964) observed suppression of fruiting branches, inhibition of flowering and reduction in yield of seed cotton by CCC. GASPER and LACOPPE (1968) noted an inhibition of growth due to the effect of CCC in barley seedlings. VED PRAKASH and LAL (1968) reported that germination of cotton seeds were stimulated in very low concentrations of CCC solution. The seeds treated with CCC produced stunted seedlings due to shortening of internodes. Cotyledonary, primary and mature leaves were found to be thick and dark green in colour. Material and methods
eee
Seeds of L. pyrotechnica were germinated in solutions of different concentrations of B 995 , and SK & F 7997-A3 and the controls in distilled water. A set of petridishes with 50 seeds
490
D. N.
SEN
and D. D.
CHAWAN
in each was placed at 30± 0 2C under 1000 lux illumination from white flourescent tubelights. Each set of experiment was replicated thrice and each replicate consisted of three petridishes. The criterion of germination was visual detection of radicle protrusion. The measurements of radicle and hypocotyl were recorded at the end of the tenth day and the results have been incorporated statistically.
Results
Germination The germination percentage for five days differed in different concentrations of the three growth retardants used here. The pace of germination in each of the three chemicals has been presented in figures 1, 2 and 3 respectively. The pace of seed germination was always slowed down with the increasing concentrations of the three retardants used. In case of B995 a cent percent germination could be observed only in 10 ppm solution at the end of the third day. The germinations and the onset of germination was delayed by one day in 1000 ppm solution of B995 (fig. 1). In case of eee a cent percent germination could be observed in 10 and 100 ppm solutions at the end of third and fourth days, respectively. However, a cent percent germination could not be observed in 500 and 1000 ppm concentration of eee during the five days duration (fig. 2). The effect of SK & F 7997-A3 appeared to be delaying the onset of germination with increasing concentrations of the chemical. In 5 and 10 ppm concentrations a
o
10 100 .500 CONe. OF B995 IN PPI1
Fig. 1. Effect of different concentration of of L. pyrotechnica.
B995
!OOO
on the pace of germination percentage in seeds
Action of Growth Retardants on the Seed Germination etc.
491
cent percent germination was completed within three days. The onset of germination was delayed by one day in 25 ppm and by two days in 50 ppm solutions. However, a cent percent germination could not be achieved in 50 ppm solution during the observation period (fig. 3).
o
10
CONe.
or
100 ,)00 CCC IN ppl'f
/000
Fig. 2. Effect of different concentrations of CCC on the pace of germination percentage in seeds of L. pyrotechnica.
700 -
o-
723 .. 5
1231,5
o ({}NC.
or
DAYS .) 10 25 SO Sf( I r 7997 - /13 IN ppl'f
Fig. 3. Effect of different concentrations of SK & F 7997-A3 on the pace of germination percentage in seeds of L. pyrotechnica.
492
D. N. SEN and D. D. eHAWAN
Growth of seedlings After germination the seedlings were kept as such in different solutions of the three growth retardants. The linear growth of the hypocot yl and radicle was measured at the end of the tenth day. The results are presented in figures 4, 5 and 6. The results presented in the above figures clearly indicate the growth inhibiting ability of of these retardants. A 10 ppm solution of eee slightly enhanced the radicle elongation. In concentrations higher than 10 ppm the growth of seedlings continued to decline till the higher concentration became inhibitory for growth completely. However, eee has not been found to be as drastically suppressing the growth of seedlings as B995 in 500 and 1000 ppm concentrations, SK & F 7997-A3 also inhibited the radicle and hypocotyl growth. The supression of linear growth was found to be more in radicle as compared to the hypocotyl. This inhibition was directly proportional to the concentrations of growth retardants. 100 -
80 -
o IIYPOCOTYL • fiAOICLE
12 50 12 ~
2::(!) ~
"
80 -
~ ~
~
'>..
;t:: W-
~
"
20 -
o-
0
10
700 .f00 7000
CONe OF 8$95 IN PPI1
o ffYPOCDTYL • RADICLE
~ ti~ E::
50 -
i:::: fO<.::>
fO -
80 -
o ffYPOeOTYL • RADICLE
f..;:
~ ~
20 -
D-
0
10
100 .f00 7000
eONC OF eee IN PPI1
20-
0-
0
.f
10
2S
so
[ONe. OF Sf("F 7991-AJ IN,P,P11
4 5 7 Fig. 4. Effect of different concentrations of B9% on the linear growth of radicle and hypoeotyl in ten days old seedlings of L. pyrotechnica.
Fig. 5. Effect of different concentrations of eee on the linear growth of radicle and hypocotyl in ten days old seedlings of L. pyrotcchnica. Fig. 6. Effect of different concentration of SK & F 7997-A3 on the linear growth of radicle and hypocotyl in ten days old seedlings of L. pyrotechnica.
Discussion
The metabolic pathway in germinating seeds appear to be regulated by many growth regulators. A large number of growth substances have been known to enhance or inhibit seed germination and seedling growth. The growth retardants have been used for inducing flower formation in some woody perennials (STUART 1961), to
1
Action of Growth Retardants on the Seed Germination etc.
493
prevent lodging in wheat (JUNG and STURM 1964) and in the formation of dwarf and bushy plantes in Bougainvillea (BOSE and HORE 1967). VED PRAKASH and LAL (1968) reported that germination of cotton seeds was stimulated in 0.05 percent eee solution. The seeds treated with eee produced stunted seedlings due to shortening of internodes. GASPER and LACOPPE (1968) noted an inhibition of growth due to the effect of eee in barley seedlings. SK & F 7997-A3 has been reported to be a strong retardant for the seedling growth of Lycopersicon esculentum MILL. var. SIOUX. (eHAWAN and SEN 1971b). The inhibiting action of SK & F 7997-A3 was reversed by gibberellin-A 3 on the seedling growth of Leptadenia pyrotechnica (eHAWAN and SEN 1971 a). In the present work, the effect of some growth retardants were studied on the quick germinating seeds of L. pyrotechnica (SEN 1968). B995 and eee slowed down the pace of germination. However, they suppressed the total germination in the higher concentrations. SK & F 7997-A3 caused delay in the germination process in higher concentrations only. The effect on the growth of radicle and hypocotyl was inhibitory with different concentrations of growth retardants. eee at lower concentrations enhanced the radicle elongation. However, the inhibitory effect was more pronounced on the hypocotyl elongation as compared to the radicle.
Acknowledgements Thanks are due to Head of the Botany Department, University of Jodhpur, for facilities and Dr. K. D. SHARMA for help in various ways. Free gift samples from Uniroyal chemicals, USA (B995); Cyanamid India Ltd. (CCC), and Smith Kleine & French Labs., UK (SK & F 7997A3) are greatfully acknowledged.
Literature BOSE, T. K., and HORE, B. K., Effect of growth retardants on some varieties of Bougainvilleas. Sci. and Cult. 33, 379 -380 (1967). CATHEY, H. M., Physiology of growth retarding compounds. Ann. Rev. PI. Physiol. Hi, 271-302 (1964). - and STUART, N. W., Comparative plant growth retarding activity of AMO-1618, Phosfon-D. Bot. Gaz. 123, 51-57 (1961). CHAWAN, D. D., and SEN, D. N., Tris-(2-diethylaminoethyl)-phosphate trihydrochloride and Gibberellin-A3 interaction in seedling growth of Leptadenia pyrotechnica (Forsk.) Decne Biochem. Physiol. 162, 108 -109 (1971 a). Inhibition of seedling growth of Lycopersicon esculentum Mill. var. Sioux. by Tris-(2-diethyl aminoethyl)-phosphate trihydrochloride - A growth retardant. Labdev. (in press) (1971 b). GASPER, '1'., and LACOPPE, J., The effect of CCC and AMO-1618 on growth, calalase, peroxidase and indole acetic acid oxidase activity If young barley seedings. Physiol. Plant. 21, 1104-1109 (1968).
494
D. N. SEN and D. D. CHAWAN, Action of Growth Retardants on the Seed Germination etc.
JUNG, J. VON, and STRUM, R., Wachstumsregulierende Wirkung von Chlorcholin chlorid (CCC). Landw. Forsch. 17, 1-19 (1964). SEN, D. N., Ecology of desert plants and observations on their seedlings. II. Germination behaviour of seeds in Asclepiadaceae. Osterr. Bot. Zeit. lUi, 18-27 (1968). STUART, N. W., Initiation of flower buds in Rhododendron after application of growth retardants. Science 134, 50-52 (1961). THOMAS, R. 0., Effect of application, timing and concentration of (2-chloroethyl) trimethyl ammonium chloride on plants size and fruiting responses of cotton. Crop. Sci. 4, 403 -406 (1964). THOMAS, C. M., and ANDERSON, J. D., Inhibition of the growth of peas by Tris-(2-diethylaminoethyl)-phosphate trihydrochloride. Plant Physiol. 41, 238-243 (1966). VED PRAKASH, and LAL, R. K., Effect of seed treatment with CCC, B995, gibberellic acid and kinetin on morphological and biochemical changes in cotton. Indian .Jour. Expt. BioI. 6, 44-46 (1968). WITTWER, S. R., and TOLBERT, N. E., (2-chloroethyl)-trimethyl ammonium chloride and related compounds as plant growth and flowering of the tomato. Amer. Jour. Bot. 47,560-565 (1960). ZEEVAART, J. A. D., Effect of the growth retardant CCC on the floral initiation and growth in Pharbitis nil. Plant. Physiol. 39, 402-408 (1964). Authors' address: Dr. D. N. SEN and Dr. D. D. CHAWAN, Botany Department University of Jodhpur, Jodhpur (India).