Gibberllic acid is one of most important growth stimulating substance used for ... The pot experiment was conducted using 90 pots of equal size filled with equal ... Table 3. ANOVA results for different soaking times and concentrations of GA3 on.
Pak. J. Pl. Sci., 14 (1): 9-13; 2008
THE EFFECTS OF DIFFERENT SOAKING TIMES AND CONCENTRATIONS OF GA3 ON SEED GERMINATION AND GROWTH OF SPINACIA OLERACEA L. Naveed Akhtar, Muhammad Ibrar and Nadia Aman Department of Botany, University of Peshawar, Pakistan Abstract An experiment was carried out with Gibberllic acid (GA3) to evaluate its effect on seed germination and growth of Spinacea olerecea L. The experiment was laid out in CRD design. Plumule length, germination percentage and number of leaves per plant were significantly affected. Maximum number of leaves and highest germination in field were recorded at 10ppm, GA3 concentration. Keywords: GA3, Seed germination, Spinacea oleracea. Introduction Spinach (Spinacea oleraceae L.) is an important potherb of Family Chenopodiaceae. It requires low temperature, sunny condition, moderately deep and highly fertile soil for its growth. In Pakistan spinach is grown over an area of 7363 hectares with a production of 79698 tones. Similarly in NWFP spinach is cultivated over an area of 1447 hectares producing 15798 tones. (Govt. of Pakistan, 2002-03). Now-a-days growth promoting hormones are commonly used in agriculture to enhance productivity. Gibberllic acid is one of most important growth stimulating substance used for promoting cell elongation, cell division and thus to promote growth and development of many plant species. Zhao-Oingyan (1995) studied the effect of GA3 on two disease resistant spinach varieties. Wang et al. (2000) observed in three different species that low concentration of GA3 slightly promoted germination but inhibited germination at high concentration. Effect of gibberellic acid on germination of Pedicularis species (Ai-Rong, 2007) Eremurus spectabilis (Rahmanpour et al., 2005), Rhodiola rosea (Aiello & Fusani, 2004) and Pterocarpus angolensis (Chisha – Kasuma, 2007) have been studied. Materials and Methods The experimental work was carried out at the Department of Botany, University of Peshawar, under the prevailing environmental conditions in the year 2004. In order to study the effects of different concentrations of GA3 for different timings on seed germination and growth of Spinacea oleracea, GA3 was applied in concentration of 75 ppm 50 ppm, 25 ppm and 10 ppm. Seeds were treated for 10, 20, 30, 60, 120 minutes and 24 hours. Similarly a control series of seeds was made for the above mentioned timings. Three replicates for each treatment were prepared. Before sowing the seeds in pots, soil used for experiment was analyzed for some physicochemical parameters like electrical conductivity, pH, available phosphorus and potassium in the soil laboratory NWFP Agriculture University, Peshawar (Table 1).
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Naveed Akhtar et al.
Table 1. Physico-chemical analysis of experimental soil. Textural class Clay loam
Percent Organic CaCO3 matter 13.90 0.719
Major elements N P K % mg/kg ppm 0.032 7.21 189.9
pH 7.5
Electrical conductivity ds / m 3.9
Germination in Laboratory The germination study on seeds treated with GA3 and control was carried out in the laboratory at 250C. The Germination percentage, radical and plumule growth was recorded after 96 hours. The germination study included. Germination in pots The pot experiment was conducted using 90 pots of equal size filled with equal quantity of clay loam soil. Seeds were sown at a depth of 1.5cm. On 2nd October ten seeds were used per pot. First irrigation was given immediately after sowing of seeds. Germination was recorded after 10 days. Plants were irrigated as and when required. Thinning was done on 1st November by leaving 5 plants per pot. Hoeing and weeding were done whenever necessary. During the vegetative growth plants were attacked with aphids. To prevent the further attack of aphids, plants were sprayed with Decovos (Domestic insecticide). Number of leaves per plant and Leaf area were measured. Results and Discussions Germination and seedling ground Germination percentage in laboratory when subjected the statistical analysis revealed that concentration soaking times and their interactions effects were non significant (Table 2). Table 2. ANOVA results for germination percentage in laboratory Source of variation GA3 conc.
Degree of freedom 4
Sum of squares 3.044
Mean squares 0.761
Time
5
2.89
Conc. X time
20
27.222
F. value
Significance
0.5569
NS
0.578
0.4228
NS
1.361
0.9950
NS
Coefficient of variation = 36.79% NS = Non significant Radicle length The maximum radicle length (44mm) was observed for seeds treated with 50ppm GA3. It is clear from the analysis of data that concentration soaking times and their interaction effects are non-significant (Table 3).
Effect of GA3 on spinach
Naveed Akhtar et al.
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Table 3. ANOVA results for different soaking times and concentrations of GA3 on radical length (expressed in mm). Source of variation GA3 conc.
Degree of freedom 4
Sum of squares 1203.039
Mean squares 300.760
Time
5
1644.212
Conc. X time
20
2496.325
F. value
Significance
0.9480
NS
328.842
1.3065
NS
214.816
0.6777
NS
Coefficient of variation = 45.50% NS = Non significant Plumule length ANOVA shows that different concentrations of GA3 had significant effect on plumule length. While time and interaction effects were non significant (Table 4). Table 4. ANOVA for effect on plumule length. Source of variation GA3 conc.
Degree of Sum of freedom squares 4 3218.599
Mean squares 804.650
F. value
Significance
9.7263
**
Time
5
235.330
47.066
0.5689
NS
Conc. X time
20
1825.514
91.276
1.1033
NS
Coefficient of variation = 112.46% ** = Highly significant NS = Non significant Germination in field In the field it was observed that concentration had a significant effect on germination percentage (Table 5). Interaction effects were also significant. But the effect of time was non significant. Maximum germination percentage was obtained for seeds treated with 10ppm concentration of GA3. Table 5. ANOVA for germination percentage in the field. Degree of freedom 4
Sum of squares 13.844
Mean squares 3.461
Time
5
2.889
Conc. X time
20
39.889
Source of variation GA3 conc.
Coefficient of variation = 11.03% * = Significant NS = Non significant
F. value
Significance
3.7083
*
0.578
0.6190
NS
1.944
2.1369
NS
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Naveed Akhtar et al.
Average Number of Leaves per Plant Maximum number of leaves were recorded in plants treated with 10ppm followed by plants treated with 75ppm. Maximum number of leaves per plant were observed in plants treated for 24 hours. Incase of interaction between concentration of GA3 and different soaking times plants treated with 10ppm for 24 hours gave maximum number of leaves per plant. The results were significant (Table 6). Table 6. ANOVA for average number of leaves per plant. Source of Degree of Sum of Mean F. value variation freedom squares squares GA3 conc. 4 73.165 18.291 3.4842
Significance *
Time
5
74.360
14.872
2.8329
*
Conc. X time
20
230.185
11.509
2.1923
*
Coefficient of variation = 12.57% * = Significant Leaf area In case of concentrations highest leaf area was recorded in control plants followed by plants treated with 10ppm GA3. The data obtained shows that concentrations time and their interaction is non-significant regarding leaf area. Conclusions The preliminary results suggested that application of 10 ppm GA3 for 24 hours might give better leaf and foliage yield. However, further elaborate study is needed for meaningful recommendation. References Aiello, N. and P. Fusani. 2004. Effects of prechilling and gibberellic acid on seed germination of rose root. Sementi Elette., 50: 33-35. Ai-Rong, L., I. Guan Kai-Yun and Robin J. Probert. 2007. Effects of light, scarification and gibberellic acid on seed germination of eight Peidcularis species from Yunnan China. Hort Science, 42: 1259-1262. Ashutosh, M., O.P. Chaturuedi and R. Bhalla. 2000. The effect of GA3 and indole acetic acid on growth and yield of football lilly. Orn. J. Hort., 3: 56-57. Chisha – Kasumu, E. 2007. Comparison of the effects of mechanical scarification and gibberellic acid treatment on seed germination in Pterocarpus angolensis. Southern Hemisphere Forestry Journal, 69: 63-70. Hussain, F. 1992. Field and Laboratory Manual of Plant Ecology. National Book Foundation Islamabad. Rahmanpour, A., A. Majid and F. Chalabione. 2005. Effects of gibberellic acid and citric acid on germination percentage speed of germination and seed vigor of Eremurus spectabilis. Iranian J. Rangel and Forests Pl. Breeding and Genetic Research, 13: 53-65.
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Wang, G. Zhousuping, W.V. Zhen, H. Xie, L. Shijun, G.D. Wang, S.P. Zhou, H.Y. Xie, and S.J. Li. 2000. Effects of several chemicals on the germination percentage of vegetables. Acta Agricultural Boreali Sinica, 15: 123-127. Zhao – Onigyan, L. Shi, R. Wang, Q. Y. Zho. R.J. Wang and D. Zhu. 1995. Selection of new spinach variety. Proceedings International Symposium on Cultivars, Improvement of Horticultural Crops, pp. 6-10. (Received 15 January, 2007; Revised September 2007)
