INFLUENCE OF DISINFESTATION AND OSMOTIC CONDITIONING ON THE GERMINATING BEHAVIOR OF AUSTRALIAN ROYAL PALM (Archontophoenix alexandrae)seeds 1

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1 155 INFLUENCE OF DISINFESTATION AND OSMOTIC CONDITIONING ON THE GERMINATING BEHAVIOR OF AUSTRALIAN ROYAL PALM (Archontophoenix lexndre)seeds 1 MÁRCIA TORRES TEIXEIRA 2, HENRIQUE DUARTE VIEIRA 3, SÍLVIO LOPES TEIXEIRA, ROBERTO FERREIRA. DA SILVA ABSTRACT - The technique of Osmotic Conditioning, which consists of prtil nd controlled hydrtion of the seeds, hs otined success with vrious species of seeds, incresing the germinting spn nd tolernce to the dverse conditions of the environment, nd hs lso reduced the time elpsed etween sowing nd the emergence of the plnts. Associted to idel storge conditions, the tretment hs incresed the performnce of the seeds of tropicl wood species. Aiming t studying the germinting environment nd the effect of osmotic conditioning on the germintion of seeds of the Austrlin Royl Plm tree, two experiments were performed. The first one evluted the effect of disinfesttion of the seeds of the Austrlin Royl Plm tree with NClO. The tretments pplied were:.5% sodium hypochlorite, exposure periods of 5, 15, 3, 5, 6, 9, 12 nd 2 minutes, nd the fungicide Cptn, s control. The tretments with NClO did not differ in reltion to the finl percentge of germintion nd to the germintion speed index, nd did not differ from the tretment control. The second test evluted solutions with the following osmotic potentils:.mp (pure wter), -.MP, -.6MP nd -.8MP, exposed for the periods of 1 nd 2 dys. The finl percentge of germintion did not differ mong the tretments. The seeds hydrted in pure wter for period of 2 dys showed germintion speed index significntly superior to the other tretments, nd they did not show significnt differences mong themselves. Index terms: germintion, sodium hypochlorite, polyethylene glicol INFLUÊNCIA DA DESINFESTAÇÃO E DO CONDICIONAMENTO OSMÓTICO SOBRE O COMPORTAMENTO GERMINATIVO DE SEMENTES DE PALMEIRA REAL AUSTRALIANA (Archontophoenix lexndre). RESUMO - A técnic de condicionmento osmótico, que consiste n hidrtção prcil e controld ds sementes, tem otido êxito com diverss espécies de sementes, umentndo cpcidde germintiv e tolerânci às condições dverss do miente, e, tmém, tem reduzido o período entre semedur e emergênci ds plântuls. Assocido às condições ideis de rmzenmento, o trtmento tem melhordo performnce de sementes de espécies róres tropicis. Ojetivndo estudr o comportmento germintivo e o efeito do condicionmento osmótico sore germinção de sementes de plmeir Rel Austrlin, form relizdos 2 experimentos. O primeiro experimento vliou o efeito d desinfestção de sementes de plmeir Rel Austrlin com o NClO. Os trtmentos empregdos form: hipoclorito de sódio,5 %, v/v, períodos de exposição de 5, 15, 3, 5,6, 9, 12 e 2 minutos, e fungicid Cptn como controle. Os trtmentos com NClO não diferirm entre si, qunto à porcentgem finl de germinção e o índice de velocidde de germinção, não diferindo do trtmento controle. O segundo teste nlisou o efeito de diferentes potenciis de soluções osmótics:, MP (águ pur), -, MP, -,6 MP e -,8 MP, expostos pelos períodos de 1 e 2 dis. A porcentgem finl de germinção não diferiu entre os trtmentos. As sementes hidrtds em águ pur pelo período de 2 dis, presentrm índice de velocidde 1 Sumitted on 26/9/25. Accepted on 21/11/26 2 Engª Agrª, MS., Lortório de Fitotecni CCTA - UENF, Cmpos dos Goytczes RJ 3 Engº Agrº, DS., Lor. de Fitotecni CCTA - UENF, Cmpos dos Goytczes RJ, henrique@uenf.r. Engº Agrº, PhD., Lortório de Fitotecni CCTA - UENF, Cmpos dos Goytczes RJ Revist Brsileir de Sementes, vol. 29, nº 1, p , 27

2 156 M.T. TEIXEIRA et l. de germinção, significtivmente superior os demis trtmentos, e estes não presentrm diferençs significtivs entre si. Termos pr indexção: germinção, hipoclorito de sódio, polietileno glicol. INTRODUCTION Brzil is the min producer nd exporter of preserved plm hert, retining 95% of the world mrket (Bovi, 1998, 22). The exports of tht industrilized product hve een incresing considerly, with n nnul medium income of thirty million dollrs (CACEX, 199). In greement with IBGE, the nnul production of plm hert hs een round sixteen thousnd tons, with 92% of it coming from the stte of Prá. Due to the extrctive nture of tht explortion, it hs een hrd to get the rw product stndrdized, wht would e possile y using cultivted plm herts, wht would llow the widening of the exports with product of good qulity (Technicl Bulletin, IAC, 1998). According to dt from Arplm - Brzilin Assocition of the Cultivted Plm Hert Producers - Brzil extrcts four hundred million plm trees yer, from which only 3% occur of res of sustinle mngement (Miglino, 22). The durtion of the germinting process of the Austrlin Rel Plm tree seeds (Archontophoenix lexndre) rnges from 3 to 9 dys, with more thn 8% of the seeds germinting. The men percentge of totl germintion rnges from 9 to 1% (Bovi, 1998). Studies hve een developed with the ojective of incresing the germinting cpcity nd the tolernce of the seeds to dverse environmentl conditions, s well s to reduce the time period elpsed etween the sowing nd the emergency of the plnts (Crvlho et l., 2). In this sense, tretment tht hs itself shown to e promising lterntive is the osmotic conditioning, tht consists of controlled hydrtion of seeds, until reching certin degree of humidity of the tissues tht induces the initil phses of germintion, ut not the protrusion of the emryonic root (Crvlho et l., 2). This technique, ssocited to the idel conditions of storge nd to the seed disinfesttion, cn improve the use of the seeds of tropicl rorel species (Borges et l., 199). The use of sodium hypochlorite is one mong severl lterntives proposed for seed disinfesttion. Such n lterntive hs een tested in this reserch, eing the sodium hypochlorite used in different concentrtions nd different periods of immersion of the propgulum (Teixeir e Teixeir, 2). The ojective of this work ws to estlish the est tretment of osmotic conditioning nd of disinfesttion of Archontophoenix lexndre seeds, in order to estlish more efficient germintion procedure. MATERIAL AND METHODS The Archontophoenix lexndre fruits were collected directly from trees growing t the Universidde Federl de Viços cmpus, Viços, MG Stte, when showing red color nd eing completely ripe. The experiments were performed t L seed of Crop Science Deprtment of Universidde Estdul do Norte Fluminense Drcy Rieiro in Cmpos dos Goytczes, RJ Stte Experiment I The tril comprised control tretment with the fungicide Cptn (,3g.1mL -1 ) nd immersion of the seeds in.5% sodium hypochlorite solution for 5, 15, 3, 5, 6, 9, 12 nd 2 minutes. The seeds of the control tretment were immersed in the fungicide solution for some seconds. The sodium hypochlorite tretments consisted in sumerging the seeds for the periods of time descried efore, following the ssemly of the germintion tests. The seeds were disposed in rolls effected with germtest pper, stored for 5 dys in BOD- type germinting chmer, under tempertures of 3-2 o C (dy/night) nd light/ drk (8/16 hours). Due to the high index of infesttion of the seeds, detected in preliminry tests, it ws necessry to estlish n efficient disinfesting method. The experimentl design ws entirely t rndom, with 9 tretments, 6 repetitions nd 18 seeds per experimentl unit. The dt were sumitted to nlysis of vrince nd the mens were compred y the test of Tukey t 5% of proility. Experiment II Fresh seeds were sumitted to the osmotic conditioning in solutions of PEG 6 (polyethylene glicol), corresponding to the osmotic potentils of zero (distilled wter); -.; -.6 nd -.8 Mp. The exposition periods comprised 1 nd 2 dys, nd the solution concentrtions for otining the osmotic Revist Brsileir de Sementes, vol. 29, nº 1, p , 27

3 157 potentils, were chosen ccording to the tle developed y Villel et l. (1991). The initil wter content of the seeds ws determined y the method of the stove t 15 o C for 2 hours (Brsil, 1992). The solutions of polyethylene glicol 6 were dded of.2% of the fungicide Cptn. The gerox-type seed oxes were put in BOD-type germintion chmer, t 25 C, for the estlished periods. At the end of the soking periods, the seeds were wshed in running wter, for one minute, nd immeditely sumitted to the germintion tests (Brccini et l., 1997). The evlutions were ccomplished ech 3 dys, tking into considertion the seeds with t lest 5mm-long roots. The experimentl design ws x 2 fctoril, entirely t rndom, with repetitions nd seeds per experimentl unit. The dt were sumitted to the Anlysis of Vrincy nd the mens compred y the test of Tukey t 5% of proility. RESULTS AND DISCUSSION Experiment I The results, ccording to the Figure 1, showed tht the seeds for the control tretment (.3% Cptn) nd the ones immersed in solution of.5% sodium hypochlorite for 5, 1, 15, 3, 5, 6, 12 nd 2 minutes, strted germinting on the 15 o dy fter the eginning of the tests, nd the seeds immersed for 9 minutes strted germinting on the 18 o dy. The nlysis of vrince showed tht tretments with NClO didn t differ mong themselves s for the finl percentge of germintion nd for the index of germintion speed (Figures 1 nd 2), not differing from the tretment IVG Fungicid with.3% Cptn. The high germintion percentges nd the high IVG, re cler evidences of the NClO not eing poisonous to the seeds. The reported results llow the conclusion tht sodium hypochlorite is efficient for the Austrlin rel plm tree seed disinfesttion. So, it should e recommended for this purpose, ecuse esides not eing poisonous to the seeds nd to the opertor, it is lso of esy hndling nd otining, eing of low cost s well. Experiment II The dt of the Figure 3 shows tht the seeds undergoing hydrtion with pure wter, for the period of 1 dys, showed Time of immersion in NClO FIGURE 2. Index of Germintion Speed of Austrlin Rel plm tree (Archontophoenix lexndre) seeds s ffected y the durtion of the immersion in.5% NClO solution. Germintion (%) Fungicide 5 min. 15 min. 3 min. 5 mni. 6 min. 9 min. 12 min. 2 min. Germintion (%) Controle -, -,6 -, Period (dys) FIGURE 1. Germintion (%) of Austrlin Rel plm tree (Archontophoenix lexndre) seeds, s ffected y the durtion of the immersion in.5% NClO solution Period (dys) FIGURE 3. Germintion (%) of Austrlin Rel plm tree (Archontophoenix lexndre) seeds s ffected y the osmotic potentils (MP) for the period of 1 dys. Revist Brsileir de Sementes, vol. 29, nº 1, p , 27

4 158 M.T. TEIXEIRA et l. initil germintion in the (3 rd ) dy fter the eginning of the tests, ccelerting the germintion ever since. The seeds immersed in PEG 6 solution, in the potentil of -. MP, egn germinting on the 6 th dy, nd, in the osmotic potentils of -.6MP nd -.8MP, on the 9 th dy, followed y the control tretment, on the 12 th dy. It is oserved (Figure ) tht the seeds hydrted in pure wter nd in the potentils of -.MP, -.6MP nd -.8MP, for the durtion of 2 dys, egn germinting soon fter the instlltion of the tests. The control tretment seeds (pure wter or zero MP) strted germinting on the 12 th dy; however, the germintion ws ccelerted, when the seeds were pre-soked for 2 dys, s compred to 1 dys. As shown y the nlysis of vrince t 5% of proility, nd considering the effect of the osmotic potentils in the rnge of the studied periods, there were not sttisticl differences mongst tretments, s for the finl percentge of germintion of the seeds. The Figure 5 shows tht the vlues of the index of germintion speed incresed, when the exposition period of the seeds to the osmotic solutions rnged etween 1 nd 2 dys. Concerning the influence of the exposition periods, inside of the estlished osmotic potentils, it ws noted tht the seeds hydrted in pure wter for 2 dys showed IVG significntly higher thn the IVG of the other tretments, nd tht these ones didn t show significnt differences mong themselves. When the seeds were hydrted for 1 dys, significnt differences were not oserved mong the tretments. The seeds of the Rel Austrlin Plm tree didn t show Germintion (%) Control -, -,6 -, Period (dys) Figure. Germintion (%) of Austrlin Rel plm tree (Archontophoenix lexndre) seeds s ffected y the osmotic potentils (MP) for the period of 2 dys. IVG dys 2 dys rdicle protrusion when sumitted to the different osmotic potentils nd different exposition times; however, the seeds showed smll opening of the operculum, when exposed for 2 dys. The sumerged seeds showed lrger opening of the operculum in osmotic potentils of -.MP nd -.6MP, thn in the -.8Mp. The control tretment didn t show opening of the operculum. The Figure shows tht tretment in pure wter (zero MP), for 2 dys, induced greter germintion uniformity, greeing with Fernndes et l. (199) results with en seeds. The results here reported show tht the immersion of Austrlin Rel Plm tree seeds in pure wter (zero MP) is the est tretment to stimulte the germintion uniformity of freshly - hrvested seeds. CONCLUSIONS NClO solution t.5%, v/v, is efficient for disinfesttion of Austrlin Rel plm tree seeds, without ffecting germintion. The pre-sok tretment of the seeds in pure wter (zero MP), for 2 dys, promotes higher finl percentge of germintion nd higher germintion speed index of the seeds s well. REFERENCES BORGES, E. E. L., SILVA, L. F., BORGES, R. C. G. Avlição do osmocondicionmento n germinção de sementes de quresminh (Miconi cndollen Trin). Revist Brsileir Control -, -,6 -,8 Tretments FIGURE 5. Index of Germintion Speed of Austrlin Rel plm tree (Archontophoenix lexndre) seeds s ffected y the osmotic potentils (MP) for the periods of 1 nd 2 dys. Revist Brsileir de Sementes, vol. 29, nº 1, p , 27

5 159 de Sementes, Brsíli, v. 16, n. 1, p. 9-9, 199. BOVI, M. L. A. Cultivo d plmeir Rel Austrlin visndo à produção de plmito. Cmpins: Instituto Agronômico, p. (Boletim técnico, 172). BRACCINI, A. L., REIS, M. S., SEDIYAMA, C. S., ROCHA, V. S., SEDIYAMA, T. Efeito do condicionmento osmótico n germinção e no vigor de sementes de soj. Revist Brsileir de Sementes, Brsíli, v. 19, n. 1, p , BRASIL. Ministério d Agricultur e d Reform Agrári. Regrs pr nálise de sementes. Brsíli: SNDA/DNDV/CLAV, p. CARTEIRA DE COMÉRCIO EXTERIOR BANCO DO BRASIL, 199. CARVALHO, L. F., MEDEIROS FILHO, S., ROSSETTI, A. G., TEÓFILO, E. M. Condicionmento osmótico em sementes de sorgo. Revist Brsileir de Sementes, Brsíli, v. 22, n. 1, p , 2. FERNANDES, P. D., AZEVEDO, N. C., BARROS, A. D. Pré - emeição seguid de secgem so o desempenho de sementes de cupi, so condições de déficit hídrico. Pesquis Agropecuári Brsileir, Brsíli, v. 29, n. 1, p , 199. INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA. Sistem IBGE de recuperção utomátic SIDRA. Censo gropecuário 21. Disponível em: < Acesso em: 2 jn. 2. TEIXEIRA, M. T., TEIXEIRA, S. L. Estelecimento de segmentos picis de mmoeiro in vitro. Revist Ceres, UFV, v. 51, n. 296, p , 2. VILLELA, F. A., DONI FILHO, L., SEQUEIRA, E. L. Tel de potencil osmótico em função d concentrção de polietileno glicol 6. e d tempertur. Pesquis Agropecuári Brsileir, Brsíli, v. 26, n. 11/12, p , 1991.!"!"! Revist Brsileir de Sementes, vol. 29, nº 1, p , 27