Vahid Ghodrat, Ali Moradshahi, Mohammad J. Rousta and Abbas Karampour

Transcription

1 merian-eurasian J. gri. & Environ. Si., 3 (6): , 203 ISSN IOSI Publiations, 203 OI: /idosi.aejaes Improving Yield and Yield Components of Rie (Oryza sativa L.) y Indolebutyri id (I), Gibberelli id (G 3) and Saliyli id (S) Pre-Sowing Seed Treatments 2 3 Vahid Ghodrat, li Moradshahi, Mohammad J. Rousta and bbas Karampour epartment of griulture, rsanjan ranh, Islami zad University, rsanjan, Iran 2 epartment of iology, College of Sienes, Shiraz University, Shiraz, Iran 3 National Salinity Researh Center, Yazd, Iran bstrat: Sine plant growth and development are ontrolled by plant growth regulators and per-sowing seed treatments have proven advantageous to germination, seedling growth and yield of several field rops, in the present study the growth and developmental responses of rie (Oryza sativa L.) ultivar Sadri to soaking seeds for three days in 0.0, 50 and 00 mg l indole butyri aid (I), gibberelli aid (G 3) and saliyli aid (S) were investigated. Perent germination and germination rate rose signifiantly in all the hormonal treatments. Root and shoot lengths were inreased signifiantly by nearly all the treatments. The fresh and dry weights at seedlings were affeted the most by I. Signifiant inrease in hlorophyll, arotenoids and antoyanins ontents of leaves ourred by soaking seeds in hormonal solutions. Exept for I, treatments did not hange tillers number signifiantly. Panile grain numbers inreased signifiantly by all the treatments, whereas, 000 kernels weight was affeted only by I and S at 50 mg l. I at 50 mg l had the highest impat on grain yield with 9.4 ompared to 7.5 ton per hetare in ontrol whih is more than 25% inrease in grain yield. mong the treatments, I at 50 mg l signifiantly affeted all the yield tested omponents. These finding strongly suggest the pratiability of seed pre-sowing hormonal treatments in produing better rop stand and higher grain yield in rie. Sine ross-talk during signal transdution ours between phytohormones, studies on the influene of seed per-sowing treatments on the grain yield prodution by ombinations of plant growth regulators are suggested. Key words: Rie Seed soaking Growth regulators Yield INTROCTION ompounds that have shown good potential to enhane germination, emergene, growth and grain yield inluded It has been estimated that half of the world s KH2PO 4, PEG and KCl [5]. When hikpea plants were population subsists wholly or partly on rie []. Therefore, raised form seeds primed with water or 4% mannitol, improved grain yield prodution has attrated the higher number of seeds and seed yield were obtained attention of many researhers. Seed invigoration ompared to ontrol plant. Higher ativities of the treatments suh as hydropriming, osmopriming, enzymes involved in surose metabolism were orrelated osmohardening and soaking before sowing have been with inreasing grain yield of hikpea rops raised reported to enhane rapid and uniform seed emergene, from primed seeds [3]. Improved rie seed invigoration vigorous seedlings prodution and inreased yield in tehniques are reported to give better stand and inreased many field rops [2, 3]. Tavaili et al. [4] reported that seed tillers number, 000 kernels weight and kernel yield in hydropriming with distilled water and osmopriming with fine, medium and oarse grain rie [7-9]. Ruan et al. [0] polyethylene glyol (PEG) 6000 signifiantly improved onduted an experiment to find out the influene of germination perentage of romus seeds. Higher vigor osmopriming of rie seeds with CaCl 2and CaCl 2+NaCl on index was observed in hydropriming for 2 hr. In wheat, germination and seedling emergene and performane in Corresponding uthor: Vahid Ghodrat, epartment of griulture, rsanjan ranh, Islami zad University, rsanjan, Iran. Tel:

2 m-euras. J. gri. & Environ. Si., 3 (6): , 203 flooded soil. Osmopriming improved seedling vigor index and seedling establishment. mong various treatments, improved seed performane has also been ahieved by priming or soaking seeds in plant growth regulators [-4]. y treating seeds with 0 ppm G 3 for 24 hrs, improved seed germination and seedling growth in vigna mungo and marotyloma uniflorum was reported by Chauhan et al, []. hatt et al. [4] found substantial inrease in germination of myria esulenta by treating seeds with 00 ppm G 3. Seed treatment with G 3aused taller mungbeen plants and inreased seed number per pod and 000 seed weight [3]. Soaking rie seeds in saliyli aid solution resulted in enhaned germination and seedling growth []. Miyoshi and Sato [5] treated dehusked seeds of india and japonia rie with kinetin and gibberellins under aerobi and anaerobi onditions. They found stimulatory effets on seed germination under most of the treatments. Priming oarse and fine rie seeds with saliyli aid resulted in vigor enhanement ompared with ontrol. Germination rate, radial and plumule length and seedling fresh and dry weights all were improved by hormonal seed priming [6]. Improved rie seed germination under salt stress by soaking seeds in gibberellins and auxin was reported by Kim et al. [7]. The exogenous appliation of G3 signifiantly inreased seed yield of hybrid rie NHR 2 [8]. lthough, seed per-sowing treatments with various substanes have been extensively investigated, information on the effets of hormonal treatments of rie seeds on grain yield and yield omponents is relatively sare. The present experiment is designed to further explore the influene of soaking rie seeds in I, G3 and saliyli aid on seed germination seedling vigour, yield and yield omponents of rie ultivar Sadri. MTERILS N METHOS This experiment was onduted in a field loated at Saadatshahr (30 5' N and 5 4' E; elevation 790 m above mean sea level) in Fars provine, Iran, during growing season. The soil physial and hemial harateristis of the experimental field are given in Table. The experiment was laid out in randomized omplete blok design with three repliations. The plant growth regulators indolebutyri aid (I), gibberelli aid (G 3)and saliyli aid (S), eah at 0.0, 50 and 00 mg l were the fators of the experiment. These hormones were weighed out and dissolved in small volume of ethanol and then brought up to the required volumes by tap water. The nursery soil was plowed in late Marh in Table : Soil physiohemial harateristis of the experimental field. Physiohemial Charateristis Physial harateristis Classifiation Claixerolli, Xerophrepts Field apaity (%) 32 Wiling point (%) 4 Silt (%) 45 Clay (%) 34 Sand (%) 23 Soil texture lay Chemial harateristis Soil ph 7.98 Potassium (mg kg ) 59 Phosphorus (mg kg ) 3 Organi arbon (%).2 Organi matter (%).4 Total nitrogen (%) 0.2 Fe (mg kg ) 8.8 Mn (mg kg ) 0.8 Zn (mg kg ) 0.62 Cu (mg kg ) 2.3 Eletroni ondutivity (dsm ) 0.55 addition to a deep plow in autumn. The nursery was reinfored by applying 250 kg ha ammonium phosphate and 50 kg ha ammonium nitrate together with ompost fertilizer. Rie (Oryza sativa L.) ultivar Sadri seeds were soaked in 0, 50 and 00 mg l of the plant growth regulators for three days. The sprouted seeds were nursery sown to provide healthy seedlings at 4- to 5 leaf stage for transplantation to the plots in the main field. The field was plowed and irrigated in pril after making long land borders and proper segmentation. mmonium - phosphate at 00 kg ha and 46% urea at 50 kg ha were applied before transplantation. In order to ontrol narrow leaf weeds, Saturan herbiide (50%) was applied 5 days after transplanting at the rate of 6 lit ha. Half of the urea was top dressed at the heading as well as the lustering stage at the rate of 50 kg ha. The plots were regularly hand weeded in different stages of growth. Eah plot was.75m wide and 7.0m long. Seedlings were planted in hills with 25*25 m arrangements and four seedlings were planted together. Germination perentage (GP) and germination rate (GR) were alulated aording to the international seed testing assoiation (IST) methods using the following equations [9]: Number of normally germinated seeds GP= Total number of seeds GR= n j i i= i 873

3 n th where is the number of seeds emerged on i day and i is the number of days ounted from the beginning of the experiment; j is set to 0 days in this experiment; root and shoot lengths, ratio of root to shoot, total fresh and dry weights, pigments ontent and tissue water ontent (TWC) of the seedlings were measured at 4- to 5 leaf stages. Pigments ontent were determined as desribe by Lihtenthale [20].The tissue water ontent (TWC) was alulated by the following formula lak and Prithard [2]: Fresh weigth-ry weigth TWC = 00 Fresh weigth m-euras. J. gri. & Environ. Si., 3 (6): , 203 Number of tillers, number of grains per panile, 000 kernels weight and plant height, length of luster, harvest index, biologial yield and grain yield were measured on mature plants. Experimental data were analyzed using SS statistial tehnique, version, 200. Treatment means were ompared by unan s multiple omparison tests at 5% probability level. RESULTS Per-sowing treatment of seeds with the plant growth regulator signifiantly inreased germination perentage and germination rate (Table 2). The most effet was observed with 50 and 00 mgl I and 00 mg l S. Shoot and root lengths of the seedlings also were signifiantly affeted by all soaking treatments. Longer roots were obtained by I treatments, whereas shoot lengths were higher when seeds were soaked in G 3. I proved to be most effetive in elevating total fresh and dry weights of the seedlings. Total water ontent of the seedlings was unaffeted by hormonal treatments. s shown in Fig. hlorophylls, arotenoids and anthoyanins ontents of the seedlings were signifiantly higher at all per-sowing treatments, exept arotenoids at 50 mg l S. Table 2 shows results obtained when yield and yield omponents were measured on mature plants. Number of tillers was signifiantly inreased by I treatments. Higher luster lengths were observed by nearly all the treatments with I having the most effet on this yield omponent. Number of grains per panile inreased signifiantly with all the tested plant growth regulators. More seeds were obtained at 50 ompared to 00 mg l treatments. t 50 mg l I, S and G 3, 3, 9 and 5 perent rise in the number of grains were Fig. : Effets of soaking rie seeds in different levels of I, G 3 and S on hlorophylls, arotenoids and anthoyanins ontents of rie seedling observed, respetively. With respet to 000 kernels weight, I at both onentration and S at 50 mg l signifiantly elevated 000 kernels weight. t 50 mg l I, inrease in 000 kernel weight ontributed about 0 perent rise in grain yield relative to ontrol. Grain yield, expressed as tons ha, inreased signifiantly in all the treatments. Soaking seeds in 50 mg l hormone influened grain yield more than 00 mg l. Compared to ontrol plants, 50 mg l I, G 3 and S elevated grain yield by 25, 4 and 2 perent, respetively. Harvest index and biologial yield were also affeted signifiantly by most of the per-sowing hormonal treatments. ISCUSSION Seed pre-sowing treatments result in enhaned germination, uniform emergene and improved yield in many field rops []. Inorporating plant growth regulators during pre-sowing seed treatments have 874

4 m-euras. J. gri. & Environ. Si., 3 (6): , 203 Table 2: Effets of soaking rie seeds in 0.0, 50 and 00mg l of I, G 3 and S on seed germination and seedling growth. Total dry Total fresh Root Shoot Root GR GP TWC weight (mg) weight (mg) shoot ratio length (m) length (m) (%) (%) E C C Control C E I50 C I00 C G350 C C C G300 C C C C S50 C C S00 Means with different letter(s) are signifiantly different using range to unan (0.05). Table 3: Effet of soaking rie seeds in different levels of I, G 3 and S on yield and yield omponents Plant Seed iologial Harvest Length of Number of Kernels 000 Number of height (m) yield (tonha ) yield (ton ha ) Index luster (m) tillers weight (g) grains per panile 35.6 E G 5.33 Control I I G F G S E 58.0 S00 Means with different letter(s) are signifiantly different using range to unan (0.05). resulted in improved seed performane [5]. This study hormonal ombinations. Therefore, researh on perrevealed that employing growth plant regulators during sowing seed treatments using ombinations of plant seed soaking treatment enhane germination as indiated growth regulators with proper onentrations will be by higher GP and GR. Inreased germination rate and valuable to raise prodution in rop ultivation. uniformity have been attributed to elevated metaboli ativates in the treated seeds [3]. It is well established that REFERENCES gibberellins and auxin regulate various developmental proesses throughout the life yle of plants [22]. G3. Farooq, M., S.M.. asra, H. Rehman, M. Hussain inreases transription of á amylase gene, stimulate the and Y. manat, Pre-sowing saliyliate seed elongation of seedling internodes and promote seed treatments improve the germination and early development. uxin is required to promote ell division, seedling growth in fine rie. Pakistan J. gri. Si., differentiation and oriented ell expansion [8]. Seed 44(): hormonal treatments also enhaned seedling vigor as 2. shraf, M. and M.R. Foolad, Pre-sowing seed seen by higher shoot and root lengths and higher total treatment a shotgun approah to improve fresh and dry weights. elerated ell division and ell germination, plant growth and rop yield under saline enlargement party explain the prodution of vigorous and non-saline onditions. dv. gron., 88: 223- seedlings by per-sowing seed treatment with plant growth 27. regulators [23]. In addition to germination and seedling 3. Kaur, S.,.K. Gupta and N. Kaur, Seed priming vigour, the three main omponents of grain yield, i.e. inreased rop yield possibly by modulating enzymes tillers number in unit area, grain numbers and 000 kernels of surose metabolism in hikpea. J. gron. Crop. weight were also inreased by seed hormonal treatments Si., 9: (Table 3). Treating seeds with 50 mg l I had the 4. Tavili,., S. Zare, S.. Moosavi and. Enayati, highest impat on seed yield whih aused 25% inrease 200. Effets of priming tehniques on seed in grain yield relative to ontrol. Therefore, establishment germination and early growth harateristis of of vigorous seedling by soaking seeds in plant growth romus tomentellos L. and romouse inermos L. regulators leads to improved yield omponents whih in Notulae. Si. io., 2(): turn influene the grain yield prodution. It is well 5. as, J.C. and.k. Choudhury, 996. Effet of seed established that ross-talk between various hormones hardening, potassium fertilizer and paraquat as antiours during plant growth and development. s a result, transpirant on rainfed wheat (Tritium aestivum l.). the output of plant hormone ation depends on speifi Indian J. gro., 4:

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