GERMINATION AND SEEDLING GROWTH OF TRAVELER'S TREE AS AFFECTED BY SOME PRE-GERMINATION TREATMENTS

GERMINATION AND SEEDLING GROWTH OF TRAVELER'S TREE AS AFFECTED BY SOME PRE-GERMINATION TREATMENTS

 

A.A. Helal^* and G.S. Eisa^**

^* Plant Production Department, Efficient Productivity Institute, Zagazig University, Zagazig, Egypt.

^** Agric. Botany and Plant Path. Department, Faculty, Agriculture, Zagazig University, Zagazig, Egypt.

 

ABSTRACT

Two factorial experiments were conducted during 2006 and 2007 seasons under glass house conditions of Efficient Productivity Institute, Zagazig University to assess the effectiveness of some seed scarification treatments (without scarification as control, dipping in hot water 80 ^oC and left seeds to cool in water for 24 hours ,  soaking in warm water 28 ^oC for 24 hours and soaking in concentrated sulfuric acid for 15 minutes) and some plant growth regulators (PGR) treatments (without PGR as control, soaking seeds in gibberellic acid solution at 300 ppm for 24 hours or soaking seeds in kinetin solution at 50 ppm for 24 hours) as well as their interactions (scarification X PGR) on Ravenala madagascariensis seed germination and seedling growth.

Subjecting seeds to warm water scarification resulted in the highest germination % at the end of the germination testing period and significantly increased both speed and value of germination comparing to control or acid scarification. In addition, both warm water and acid scarification significantly increased seedling growth rate (mg dry weight/ day) and seedling length rate (mm tall/ day).    

Soaked-seeds in GA₃ solution at 300 ppm for 24 hours were significantly earlier in protrusion their seedlings and resulted in the highest values represented germination percentage, germination value, seedling vigor and plant growth parameters (plant height, leaf No/ plant, shoot fresh and dry weights/ plant) as compare to soaked seeds in kinetin at 50 ppm or control treatment.

   Interaction treatments between scarification and soaking in PGR showed that the more pronounced enhancing effect on germination percentage, germination speed, germination value, seedling vigor and plant growth parameters was found when seeds were subjected to warm water scarification for 24 hours and then soaked in GA₃ at 300  ppm for another 24 hours. Acid scarification when interacted with PGR accelerated germination, but resulted in the least values of germination % comparing to the other interaction treatments.    

   Key words:Germination, Ravenala madagascariensis, traveler's tree, traveler's palm, warm water scarification, acid scarification, gibberellic acid, kinetin.  

 

INTRODUCTION

   Ravenala madagascariensis, also known as traveler's tree or traveler's palm, is a tropical tree belong to the same family of bird of paradise (Fam: Strelitziaceae) and native to the island of Madagascar. It has very distinctive hand fan shaped foliage and it can grow up to 10 to 20 m tall. Leaves can be up to 3 m long. It can be planted outdoors in tropical landscapes that are free from frost and strong winds or indoors and in greenhouses where lighting is plentiful and where the container in which it is growing restricts plant size. As for propagation, it may be propagating by seeds or by division and replanting of clumps (suckers) formed at the plant base (Floridata.com L.C .Tallahassee, 2005). Edward and Dennis(2006) stated that traveler's tree seeds are slow to germinate. Also, Thompson and Morgan (2008) published that germination of Strelitzia and similar plants can start within 7 days and carry on for 6 months or more.

     Mechanically resistant seed coats, impermeable seed coats, and/ or presence of germination inhibitors may be constituent important reasons which cause seed dormancy and delay germination (Nickell, 1982).

Seed coat plays a major role in delaying some seed germination. The cause of the inhibitory action of the seed coat on germination is mainly due to impermeability to water and oxygen. Water permeability in hard seeds becomes possible after damaging the seed coat by physical, chemical, or biological factors. Scarification is the most widely used method for destroying the seed coat. Scarification has been recommended in the case of katsura tree, honey locust, and other plants (Ovcharov, 1977). Hartmann et al. (1997) published that scarification is any process of breaking, scratching, mechanically altering, or softening the seed coverings to make them permeable to water and gases. Three types of treatments commonly used as scarification; i.e., mechanical, chemical and hot water treatments.

    According to Ovcharov (1977), treating seeds with hard coats with sulfuric acid has become a common practice as a chemical scarification treatment. Removing the hard and impermeable seed coats of Lathyrus maritimus with concentrated sulfuric acid sharply increased germination. Also, soaking Ipomoea crassiculis (Benth.) seeds, which enveloped in a thick coat that does not allow water penetration, in concentrated sulfuric acid for 12- 15 hours created favorable conditions for water permeability and ensured 100% germination. Recently, Shahin and Arafa (2007a) on Butia capitata, (Mart) and Shahin and Arafa (2007b) on Hyphaene thebaica, L. Mart recorded significant improvements in germination (%), germination velocity, mean germination rate, vigor index and quality of produced seedlings (assessed as: seedling height, root length and fresh and dry weight of aerial parts and roots/ seedling) under the effect of acid scarification in concentrated sulfuric acid for 6 hours.  

     Gibberellin (GA) is an essential phytohormone that controls many aspects of plant development. Ovcharov (1977) in his text concluded that gibberellins stimulated seed germination in pine, grape, mustard, cabbage and other plants. Generally soaking seeds of dwarf varieties in a 0.001 to 0.01% gibberellic acid solution accelerated germination and plant growth. Germination of meadow grass seeds was stimulated under the influence of seed soaking in gibberellins at 250 mg/l. Also, gibberellic acid treatments at 250 to 1000 mg/l of seeds which have under-developed embryos stimulated germination of subtropical plants. Moreover, soaking grains of winter barley at 100 mg/l, ray and wheat at 200 mg/l, and oat at 400 mg/l of gibberellic acid solutions accelerated their germination.

     Krishnamoorthy (1981) summarized that seed dormancy and germination in many plants appears to be controlled by GA-ABA balance. In many plants soon after the seeds imbibes water during germination, gibberellins or GA-like substances are increase. Hartmann et al. (1997) stated that applied gibberellins can relieve certain types of dormancy, including physiological dormancy, photo dormancy and thermo dormancy. Peng and Harberd (2002) published thatseed germination is promoted by gibberellin (GA) in many plant species. Several GA signaling factors are known to induce the expression of genes encoding enzymes that mobilise food reserves, including starches, proteins and lipids, stored in the endosperm during seed germination. When Rogis et al. (2004) assessed the germination of three seed lots of eastern gamagrass to 1 mM GA₃ and exposure to 4 ^oC for 0 to 7 weeks found that germination of seed soaked in GA₃ solution was significantly higher than the germination of water soaked seed. The most pronounced effect of GA₃ was more rapid germination of seed in all of the stratification durations tested

     Cytokinins also play an important role in accelerating seed germination, Kefford et al.,(1965) found that kinetin stimulated germination of lettuce seeds. In addition, Khan and Tolbert, (1965) stated that kinetin at 50 mg/l reduced the inhibitory effect in lettuce seeds caused by interfere light, treatment with coumarin, or growth inhibitor from mature wheat seeds. However, cytokinin is believed to offset the effect of inhibitors, notably ABA, during seed germination. It has been described as playing a permissive role in germination in allowing gibberellic acid to function. Applied cytokinin can also be effective in overcoming thermo dormancy (Hartmann et al., 1997).

      Egyptian gardeners noticed, under the local conditions, rare seed production, slow and unsatisfactorygermination, as well as slow growth in Ravenala madagascariensis seedlings. So, the objective of this research was to assess the effectiveness of some scarification treatments (dipping in hot water, soaking in warm water and soaking in concentrated sulfuric acid) and some plant growth regulators treatments (soaking in gibberellic acid or in kinetin solutions) as well as their interactions (scarification X plant growth regulator treatments) on Ravenala madagascariensis seed germination and seedling growth.

MATERIALS AND MITHODS

      This work was carried out duringthe two successive seasons of 2006 and 2007 under the glass house conditions of Efficient Productivity Institute, Zagazig University, Egypt,aiming to assess the effectiveness of some scarification treatments (dipping in hot water, soaking in warm water and soaking in concentrated sulfuric acid) and some plant growth regulator (PGR) treatments (soaking in gibberellic acid or in kinetin solutions) as well as their interactions (scarification X PGR treatments) on Ravenala madagascariensis seed germination and seedling growth.

      Seeds of Ravenala madagascariensis were received from a commercial nursery on February 1^st of the same year of their production and were stored until March 1^st for the experimental use in the two tested seasons.

On March 1^st for the two tested seasons seeds were stripped off the blue flesh, cleaned and subjected to scarification and PGR treatments.

 

Scarification treatments included:

1. Control; as dry seeds without any treatments.
2. Hot water treatment; was carried out according the procedures described by Hartmann et al. (1997) as dropping the seeds into (5 times of their volume) hot water (80 ^oC). Then, the soaked seeds were left to cool in the same water for 24 hours. This treatment did not repeated in the second season (2007) because it's severe inhibitory effect on germination. Also, it was canceled from statistical analysis of the first season (2006).
3. Warm water treatment; was as soaking the seeds in 5 times their volume of water in a glass container placed into bath water at constant temperature of 28 ^oC for 24 hours.
4. Sulfuric acid treatment; was done by placing the seeds in glass container and covering them with concentrated sulfuric acid (in a ratio of one part seed to two parts acid, v: v) for 15 minutes, then acid was poured off, and the seeds were washed for ten minutes in running water to remove the remainder acid (Hartmann et al., 1997).

 Following this, seeds of each scarification treatment were divided into four equal portions; the first quarter was directly sown, while the three quarters were subjected to the PGR treatments.

Plant growth regulator treatments (PGR) included:

1. Control; seeds were sown without any PGR treatments.
2. Seeds were soaked in gibberellic acid (GA₃) solution at 300 ppm for 24 hours before sowing.
3. Seeds were soaked in kinetin solution at 50 ppm for 24 hours before sowing.

    The Experimental layout was factorial experiment between the above mentioned scarification treatments and seed soaking in PGR in a complete randomized design (Das and Giri, 1986) with three replicates, each replicate contained 40 seeds.

    Treated seeds were sown on March 1^st of the two tested seasons. Cell trays filled with German peat moss were used for seed sowing. Sown seeds were left under glass house conditions. Thereafter, trays were irrigated once per week and received the usual agricultural practices whenever needed. The germination testing period was terminated 3 months after sowing (June 1^st) for the two tested seasons.

     At the sixth count of germinated seeds (on May1st) for the two seasons, to determine seedling growth parameters, the germinated seedlings of each treatment were transplanted into 12 cm plastic pots filled with German peat moss and were left under glass house conditions. Plants were received the normal agricultural practices whenever needed for other 3 months until August 1^st.

 

Recorded Data:

I. Germination data:

Germinated seeds were periodically counted at ten day intervals and terminating 3 months after seed sowing (June 1^st), since no additional germination was noticed during the two tested seasons. Clearly visible plumule protrusion was used as a criterion for germination. Then, the following germination data were calculated:

 1. Cumulative germination percentage for each count was calculated using standard procedures described in AOSA (1981) as a percent of normal seedlings produced from the total sowing seed number, as an indicator for seed viability.

2. Germination speed calculated according to equation described by Joshi and Singh (2003) as follows:

                Germination speed = Number of normal seedling (first count)/ days to first count + Number of normal seedling (second count)/ days to second count + --------------- + Number of normal seedling (final count)/ days to final count.

3. Germination value (GV) was determined, implicating both germination rate and percentage, according to Czabator (1962) with the equation described by Hartmann et al. (1997) as follows:

GV = PV X MDG,   Since; PV (peak value) is the germination % at the point which the germination rate begins to slow down divided by the days to reach that point. While, MDG (mean daily germination) is the final germination % divided by number of days to reach final germination.

II. Seedling growth and vigor tests data

On August 1^st, for the two experimental seasons, plant height (cm), leaf No/ plant and shoot and root fresh and dry weights/ plant (g) were recorded. In addition, seedling length rate (mm/ day) and seedling growth rate (mg/ day), as a seedling vigor tests, were calculated by divided the final plant height and the total plant dry weight by number of growing days.

Statistical analysis:

The collected data were subjected to statistical analysis according to Steel and Torrie (1980). Mean separation was done using Duncan’s multiple range test at 5% level (Duncan, 1958).

RESULTS AND DISCUSION

1. Germination Percentage:

Effect of scarification

  Cumulative percentages of germinated seeds from the total number of sown seeds at ten days intervals as affected by scarification treatments are recorded in Table 1. It is obvious that seed soaking in warm water (28 ^oC) for 24 hours resulted in the highest final germination % at the end of the germination testing period as compare to control or seed soaking in concentrated sulfuric acid for 15 minutes. In addition, sowing seeds without any scarification resulted in higher total germination % than seed treated with acid scarification. This was confirmed during the two tested seasons. It is worth to mention that hot water (80 ^oC) scarification treatment did not produce any germinated seeds (non published data). However, the enhancing effect of warm water soaking might be due to the softening of seed coat which may permitted more penetration of water and oxygen leading to more leachate of inhibitors from the seed and in turn resulted more activation in germination processes. While, concentrated sulfuric acid may be resulted harmful effect on the seed embryo leading to suppressive effect on germination.

Effect of seed soaking in PGR:

               Data in Table 1 show that soaking seeds in GA₃ solution at 300 ppm produced the highest germination % from the second count (20 days) to the sixth count (60 days) as compare to control or soaking in kinetin at 50 ppm during the two seasons. This implicates the enhancing effects of GA₃ on germination processes. Similar results were previously reported by Ovcharov (1977) and Rogis et al. (2004). Additionally, Krishnamoorthy (1981) said that seed dormancy and germination in many plants appears to be controlled by GA-ABA balance. In many plants soon after the seeds imbibes water during germination, gibberellins or GA-like substances are increase. Also, Peng and Harberd (2002) published that

 

Table 1. The cumulative percentage of germinated Ravenala madagascariensis seeds (at ten day intervals after sowing) as affected by seed scarification and soaking in GA₃ or kinetin during 2006 and 2007 seasons

Means having same alphabetical letter(s) within each column did not significantly differ according to Duncan's multiple range test at 5% level.

 

seed germination is promoted by gibberellin (GA) in many plant species. Several GA signaling factors are known to induce the expression of genes encoding enzymes that mobilise food reserves, including starches, proteins and lipids, stored in the endosperm during seed germination.

 

Effect of interaction between seed scarification and soaking in PGR

Data presented in Table 2 and illustrated in Figure 1, show significant interaction effect between seed scarification and seed soaking in PGR on Ravenala seed germination at different recorded counts after sowing. The more pronounced enhancing effect on germination % was found when seeds were subjected to warm water scarification for 24 hours and then soaked in GA₃ at 300 ppm for another 24 hours. Since, this interaction treatment significantly increased percentage of germinated seeds at each count comparing to the most other interaction treatments during the two seasons. Also, it recorded the highest germination % at the end of germinating testing period (75.6 and 73.3 for first and second seasons, respectively) comparing to the  all  other  interaction  treatments. Although, acid  scarification  when

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

interacted with PGR resulted the least values of germination % comparing to the other interaction treatments, it accelerated germination to approach to the constant percentage (about 50 days comparing to about 70 days for other interaction treatments, Figure 1). However, the synergistic effect of seed soaking in warm water and then in GA₃ solution might be expected as a result of leaching inhibitors from seed during soaking in water in addition the warmness might be activated the metabolic processes in seed which made a proper situation to receive GA application, leading to more germination enhancement. Pillay et al. (1965) have proposed that the enrichment of seeds with gibberellic acid destroys the period of dormancy and enhance the synthesis of those physiologically active substances essential for seed germination. According to Krishnamoorthy (1981), soon after the seeds imbibe water during germination, gibberellins or GA-like substances are increase. Gibberellin acts on the living cells, surrounded the storage food in seed, and causes synthesis of hydrolyzing enzymes, particularly alpha-amylase and protease which in turn hydrolyses the reserve food, thus renders it available for the growth of the embryo. Also, GA is shown to increase the synthesis of RNA and proteins in the embryo leading to emergence of the radical.

2. Germination speed (GS) and Germination Value (GV):

Effect of scarification:

  It is clear that soaking seeds in warm water significantly increased both GS and GV comparing to control or acid scarification during the two tested seasons (Table 3). Acid scarification increased GS in the second season, but it significantly reduced GV in the first season and had no significant effect in this regard in the second one as compare to control. However, warm water treatment may be softened the seed coat and created favorable conditions for water permeability and gases exchange, beside the warmness may be activated the biochemical reactions inside the seed leading to earlier germination and high germination value. While, the tendency of acid scarification to increase GS may be resulted from the acid effect on seed coat, but its suppressive effect on GV may be resulted from a harmful effect on seed embryo after acid treatment. Ovcharov (1977) stated that sulfuric acid scarification did not increase cereal seeds germination, and gave poor germination with wheat seeds even with a very low concentration. While, Shahin and Arafa (2007a) on Butia capitata, (Mart) and Shahin and Arafa (2007b) on Hyphaene thebaica L. Mart recorded significant improvements in germination velocity under acid scarification effect.   

Effect of seed soaking in PGR:

Data of the same Table 3 indicate that soaked seeds in GA₃ solution at 300 ppm were significantly earlier in protrusion their seedlings than soaked seeds in kinetin at 50 ppm or control treatment. Also, GA₃-treated seeds resulted  in  the  highest  GV  during  the  two  seasons.  Kinetin  at the used

Table 3. Germination speed and germination value of Ravenala madagascariensis as affected by seed scarification and soaking in GA₃ or kinetin during 2006 and 2007 seasons

Means having same alphabetical letter(s) within each column did not significantly differ according to Duncan's multiple range test at 5% level.

 

Table 4. Germination speed and germination value of Ravenala madagascariensis as affected by seed scarification (Scari.) as soaking in warm water (WW) or sulfuric acid (SA) interacted with soaking in some plant growth regulators (PGR) during 2006 and 2007 seasons

Means having same alphabetical letter(s) within each column did not significantly differ according   to Duncan's multiple range test at 5% level.

 

concentration hadn't any favorable effect respecting GS or GV during the two seasons. However, the enhancing effect of GA₃ on GS and GV may be explained as a result of the simulative effects of GA on the internal processes leading to earlier germination and high germination value. Similar results respecting GS were previously reported by Ovcharov (1977) on winter barley, ray, wheat and oat after seed soaking in GA₃. It is proposed that gibberellic acid enhance the synthesis of those physiologically active substances essential for seed germination. Protsko and Dudchenko (1964) found that the quantity of glutamine and asparagine was significantly increased in GA₃-treated pea seeds; these compounds are participating directly in the oxidative-reductive process of germinating seeds. In addition, Krishnamoorthy (1981) stated that gibberellin is shown to increase the synthesis of hydrolyzing enzymes, particularly alpha-amylase and protease which in turn hydrolyses the reserve food thus renders it available for the growth of the embryo. Also, GA enhances the synthesis of RNA and proteins in the embryo leading to emergence of the radical.

Effect of interaction between seed scarification and soaking in PGR:

When scarification interacted with PGR (Table 4), generally, the interaction treatment between warm water scarification and soaking in GA₃ resulted in the highest significant value represented GS and GV comparing to most of the other interaction treatments during the two seasons. This result was predicted, since soaking seeds in warm water may be make seeds in suitable activation and have more responses for the subsequent GA₃ treatment than warm water or GA₃ treatments, each alone.

3. Seedling Growth and Vigor Tests:

Effect of scarification:

Results in Table 5 show that seed scarification treatments (warm water or acid) significantly enhanced seedling growth vigor determined as seedling length rate (mm/ day) or seedling growth rate (mg/ day) and in turn significantly increased all studied growth parameters; i.e., plant height, leaf No/ plant and shoot and root fresh and dry weights/ plant comparing to control. Shahin and Arafa (2007a) on Butia capitata, (Mart) and Shahin and Arafa (2007b) on Hyphaene thebaica L. Mart recorded significant improvements in quality of produced seedlings (assessed as: seedling height, root length and fresh and dry weights of aerial parts and roots/ seedling) under the effect of acid scarification in concentrated sulfuric acid. the earlier germination of soaked-seeds in warm water (as mentioned above) might be permit more increments in plant growth and vigor tests as compare to the late germinated seeds under control treatment.

Effect of seed soaking in PGR:

Generally, soaking Ravenala seeds in GA₃ was more effective than kinetin in enhancing seedling vigor and subsequent plant growth. Since, GA₃-treateed seeds resulted in the highest values of plant height, leaf No/ plant, shoot fresh and

 

  Table 5. Some growth characteristics of Ravenala madagascariensis seedlings as affected by seed scarification and soaking in GA₃ or kinetin during 2006 and 2007 seasons

Means having same alphabetical letter(s) within each column did not significantly differ according to Duncan's multiple range test at 5% level.

 

dry weights/ plant as well as seedling length rate and seedling growth rate as compare to kinetin or control treatments during the two seasons (Table 5).

Ovcharov (1977) have visualized an important role of gibberellins in blocking growth inhibitors which suppress the growth processes. Since, the enrichment of pea seeds with gibberellins stimulated seedling growth, led to a reduction in the quantity of indole acetic nitrate, and caused a loss of the β-inhibitor in the apical bud.

 

Effect of interaction between seed scarification and soaking in PGR

Data represented the effect of interaction between scarification and seed soaking in PGR on seedling vigor tests and plant growth are in Table 6.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  Generally, it could be conclude that the double treatment of seeds with scarification (warm water or sulfuric acid) and soaking in PGR (GA₃ or kinetin) resulted in high values of seedling length rate and seedling growth rate as well as plant growth parameters comparing to scarification or PGR each alone. However, the earlier germination in double treated seeds (scarification X PGR soaking) might be created the opportunity for more growth of the resulted seedlings.

 

CONCLUSION

    According the previous results, it could be concluded that the double treatment of seed soaking in warm water (28 ^oC) for 24 hours, and then soaking in solution containing GA₃ at 300 ppm for other 24 hours was suitable for improvingseed germination and subsequent seedling growth of Ravenala madagascariensis.

REFERENCES

AOSA. 1981. Association of Official Seed Analysts. Rules for testing seeds. J. Seed Technol. 6.

Czabator, F. 1962. Germination value: an index combining speed and completeness of pine seed germination. For. Sci., 8: 386- 396.

Das, M.N. and N.C, Giri, 1986. Design and Analysis of Experiments, 2^nd Ed., Published by Mohinder Singl Sejwal for Wiley, New Delhi.

Duncan, D. B. 1958. Multiple range and multiple F test. Biometrics, 11: 1- 42.

Edward, F.G. and G.W. Dennis. 2006. Ravenala madagascariensis: Travelers-tree. IFAS, Univ. Florida. (Available on line on April 1^st 2008) http://edis.ifas.ufl.edu/pdffiles/ST/ST56500.pdf  

Floridata.com L.C .Tallahassee. 2005. Ravenala madagascariensis. Florida USA. (Available on line on April 1st 2008) http://www.floridata.com/ref/R/rave_mad.cfm

Hartmann, H.T., D.E. Kester, F.T. Daviesand R.L. Geneve. 1997. Plant Propagation Principles and Practices. Prentice-Hall. International (UK) Limited, London.

Joshi, A.K. and B.D. Singh. 2003. Seed Science and Technology. Kalyani Publishers. Ludhiana. New Delhi.

Kefford N.P., J.A. Zwar and M.I. Bruce. 1965. Enhancement of lettuce seed germination by some urea derivatives. Planta, 67 (1): 103- 106.

Khan, A.A. and N.E. Tolbert. 1965. Reversal of inhibitors of seed germination by red light plus kinetin. Physiol. Plantarum, 18 (1): 41- 43.

Krishnamoorthy, H.N. 1981. Plant Growth Substances. Tata McGraw-Hill Publishing Company Limited. New Delhi.

Nickell, L.G. 1982. Plant Growth Regulators Agricultural Uses. Springer-Verlag, Berlin Heidelberg  NY.

Ovcharov, K.E. 1977. Physiological Basis of Seed Germination. Ameriind Publishing Co. PVT. LTD. New Delhi.

Peng, J. and N. P. Harberd. 2002. The role of GA-mediated signalling in the control of seed germination. Current Opinion in Plant Biology, 5 (5): 376-381. (Available on 1^st April 2008). http://www.sciencedirect.com/hit2

Pillay, D.T.N., K. Brase and L.J. Edgerton. 1965. Relationship of growth substances to rest period and germination in Mazzard cherry seeds. Pros. Amer. Soc. Hort. Sci., 86: 108- 114.

Protsko, R.F. and L.G. Dudchenko. 1964. On the mechanism of action of gibberellin: 1. Gibberellin on the system of ascorbic acid and glutathione. Ukrainsk. Bot. Zhurn., 21: (6): 3- 9. (C.F.Ovcharov, K.E. 1977. Physiological Basis of Seed Germination. Ameriind Publishing Co. PVT. LTD. New Delhi.)

Rogis, C., L. R. Gibson, A. D. Knapp, and R. Horton (2004). Enhancing germination of eastern gamagrass seed with stratification and gibberellic acid. Crop Sci., 44:549–552.

Shahin, S.M. and A.M.S. Arafa (2007a). Germination of butia palm seeds as affected by pre-germination treatments. J. Product. & Dev., 12 (2): 401- 410.

Shahin, S.M. and A.M.S. Arafa .2007b. Germinationof doum palm (Hyphaene thebaica, L. Mart.) seeds as affected by some scarification treatments. J. Product. & Dev., 12 (2): 453- 462.

Steel, R.G.D. and J.M. Torrie. 1980. Principles and Procedures of Statistics, A Biometrical Approach. McGraw - Hill Book Company, New York.

Thompson and Morgan Guide. 2008. Seed Germination Database. (Available on April 1^st) http://www.backyardgardener.com/tm.html 

 

 

 

 

 

 

 

 

 

 

 

 

 

تأثیر بعض معاملات ما قبل الإنبات على إنبات بذور شجرة المسافر ونمو بادرتها

 

¹عبد المحسن عبد الشافی هلال – ²جلال سرور عبد الحمید عیسى

¹ قسم الإنتاج النباتی- معهد الکفایة الإنتاجیة- جامعة الزقازیق.

² قسم النبات الزراعی وأمراض النبات – کلیة الزراعة – جامعة الزقازیق.

 

أُُجریت تجربتان عاملیتان خلال موسمی 2006 ، 2007 تحت ظروف الصوبة الزجاجیة   لمعهد الکفایة الإنتاجیة، جامعة الزقازیق لتقییم تأثیر بعض معاملات تلیین غلاف البذرة (بدون معاملة للمقارنة ، الغمس فی ماء ساخن 80 ^Oم ثم ترک البذور لتبرد فی الماء لمدة 24 ساعة ، النقع فی ماء دافئ 28 ^Oم لمدة 24 ساعة ، أو النقع فی حمض کبریتیک مرکز لمدة 15 دقیقة) ، وبعض معاملات منظمات النمو النباتیة (بدون معاملة للمقارنة ، نقع البذرة فی محلول حمض الجبریلک بترکیز 300 جزء فی الملیون لمدة 24 ساعة ، أو نقع البذرة فی محلول کینیتین بترکیز 50 جزء فی الملیون لمدة 24 ساعة) بالإضافة إلى تفاعلاتهم على إنبات بذور ونمو بادرات نبات شجرة المسافر.

أدى تعریض البذور لمعاملة تلیین الغلاف بالماء الدافئ إلى إنتاج أعلى نسبة إنبات عند نهایة فترة اختبار الإنبات ، والى زیادة معنویة فی کل من سرعة وقیمة الإنبات  مقارنةً بالمعاملة بحمض الکبریتیک أو بالکنترول. کذلک ، أدت کل من المعاملة بالماء الدافئ أو بحمض الکبریتیک إلى زیادة معنویة فی معدل نمو البادرة (مللیجرام مادة جافة/ یوم) ومعدل زیادة البادرة فی الطول (مللیمتر/ یوم).

أدت زراعة البذور المنقوعة فی محلول حمض الجبریلک بترکیز 300 جزء فی الملیون لمدة 24 ساعة إلى التبکیر فی ظهور بادراتها ، وکذلک أنتجت أعلى القیم الممثلة لنسبة الإنبات ، وقیمة الإنبات  ، وقوة البادرة ، وقیاسات نمو النبات (ارتفاع النبات ، عدد الأوراق/ نبات ، والوزن الغض والجاف للمجموع الخضری/ نبات) مقارنةً بالبذور المنقوعة فی الکینیتین بترکیز 50 جزء فی الملیون أو بمعاملة المقارنة.

أظهرت معاملات التفاعل بین معاملات تلیین غلاف البذرة والنقع فی منظمات النمو النباتیة أن التأثیر المنشط الأکثر وضوحا على نسبة الإنبات ، وسرعة الإنبات ، وقیمة الإنبات ، وقوة البادرة ، وقیاسات نمو النبات وُجد عندما عُرضت البذور لمعاملة تلیین أغلفتها لمدة 24 ساعة فی الماء الدافئ ثم نُقعت بعد ذلک فی محلول حمض الجبریلک بترکیز 300   جزء فی الملیون لمدة 24 ساعة أُخرى. أدى تفاعل المعاملة بحمض الکبریتیک مع النقع فی منظمات النمو النباتیة إلى إسراع الإنبات ولکنه أعطى اقل قیم لنسبة الإنبات مقارنةً بمعاملات التفاعل الأخرى.  

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