Effects of temperature on the germination of Diptychandra aurantiaca (Fabaceae) seeds

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1 Act Scientirum ISSN printed: ISSN on-line: Doi: /ctscigron.v35i Effects of temperture on the germintion of Diptychndr urntic (Fcee) seeds Ademir Kleer Moreck de Oliveir 1*, Jonthn Wesley Ferreir Rieiro 2, Kelly Cristin Lcerd Pereir 2 nd Cssil André Arújo Silv 2 1 Progrm de Pós-grdução em Meio Amiente e Desenvolvimento Regionl, Universidde Anhnguer-Uniderp, Ru Alexndre Herculno, 1400, , Cmpo Grnde, Mto Grosso do Sul, Brzil. 2 Deprtmento de Ciêncis Biológics, Universidde Anhnguer-Uniderp, Cmpo Grnde, Mto Grosso do Sul, Brzil. *Author for correspondence. E-mil: kmoreck@hotmil.com ABSTRACT. Diptychndr urntic is tree elonging to the Fcee fmily. The wood of this tree is modertely hevy nd resistnt, nd it is used to mke posts, wooden sleepers nd uilding, mong other structures. The im of this work ws to evlute seed germintion nd the initil growth of the primry roots in D. urntic t different tempertures using seeds collected in the villge of Toco in Mto Grosso do Sul stte, Brzil. The seeds were sujected to constnt tempertures of, 25, nd 35 C nd lternting tempertures of - nd C using four replictions of 25 seeds per tretment in germintion chmer. The results showed tht most seeds germinted t 25 nd C, with 97 nd 87%, respectively, thus indicting tht these tempertures re efficient to not only promote germintion ut lso to potentite the speed (1,1-25 nd C) nd decrese the verge germintion time ( C nd C), highest lloction of dry iomss ( g t 25 C nd g t C) nd the gretest primry root size (17.5 mm t 25 C nd 16.5 mm t C). Keywords: rod-lefed, semi-deciduous, svnnh (Cerrdo), forest seeds, true-red-chrcol. Efeito d tempertur sore germinção de sementes de Diptychndr urntic (Fcee) RESUMO. Diptychndr urntic é um árvore d fmíli Fcee. Como utilidde, mdeir, moderdmente pesd e resistente, é utilizd n fricção de postes, dormentes, construção civil, entre outros usos. O ojetivo deste trlho foi vlir germinção ds sementes e crescimento d riz primári em diferentes temperturs, com sementes coletds n região do Toco, Mto Grosso do Sul. As sementes form sumetids temperturs constntes de, 25, e 35 C e lternds de - e C, com qutro repetições de 25 sementes por trtmento em câmrs de germinção. Os resultdos otidos evidencirm mior percentgem de germinção ds sementes ns temperturs de 25 e C, tingindo 97 e 87%, respectivmente, indicndo que ests temperturs são mis eficzes em promover germinção, propicindo tmém mior velocidde de germinção (1,1-25 e C), menor tempo médio de germinção (9,0-25 C e 7,1 - C), mior locção de mss sec (0,0067 g 25 C e 0,0055 g C) e comprimento d riz primári (17,5 mm em 25 C e 16,5 mm em C). Plvrs-chve: florests ltifolids, semidecídus, cerrdão, sementes florestis, crvão-vermelho-verddeiro. Introduction In recent yers, n incresing numer of studies hve een imed t propgting ntive forest species due to current environmentl prolems nd the need to restore or recover ntive vegettion in res of degrdtion (OLIVEIRA et l., 05). Furthermore, knowledge out Brzilin ecosystems is still scrce, especilly with respect to seed germintion in ntive species nd in light of the enormous iologicl potentil of these systems (BRANCALION et l., 10). Seed germintion is considered to e the resumption of the metolic ctivities of the emryo- nic xis tht eventully culmintes in the criticl phse of primry root protrusion, ssocited with the physiologicl processes occurring in seed. It is dependent on environmentl fctors, such s wter, light, temperture nd oxygen, therey confirming our understnding of the idel conditions required for the germintion of seeds in predetermined species (BRASIL, 09; CARVALHO; NAKAGAWA, 00; CASTRO et l., 04). Temperture is n environmentl fctor tht significntly ffects germintion. However, there is no optimum nd uniform temperture for ll species. Temperture ffects the speed nd

2 4 Oliveir et l. percentge of germintion, primrily influencing wter uptke nd impcting the iochemicl rections nd physiologicl processes tht determine germintion (CARVALHO; NAKAGAWA, 00; TAIZ; ZEIGER, 09). Germintion occurs within defined temperture rnge nd will not occur ove or elow these limits. The idel temperture will permit mximum germintion in the lest mount of time (CARVALHO; NAKAGAWA, 00). Mrcos Filho (05) stted tht the optimum temperture llows for the most efficient comintion of the percentge nd speed of germintion. Temperture is lso fundmentl for the development of specific prts of seedlings nd primry roots, generlly the first prts of the plnt to protrude during germintion. Indequte tempertures directly ffect root growth, process in which cells re rpidly dividing, nd ny dverse environmentl fctor diminishes the cpcity of the root for development (LARCHER, 03). The tree species Diptychndr urntic (Mrt.) Tul., commonly known s crvão-vermelho-verddeiro (true-red-chrcol) or lsminho (little Blsm), elongs to the Fcee fmily. This species reches height of 8-14 m nd hs rectiliner trunk. D. urntic is commonly found in the rodleved, semi-deciduous forests nd dense svnnhs of Mto Grosso do Sul, São Pulo, Mins Geris nd Goiás Stte. Its modertely hevy, hrd, resistnt wood is extremely durle, even in outdoor environments, nd is used in the friction of posts, sleepers nd chrcol nd for civil construction, mong other pplictions. Despite their deciduous nture, these trees re considered to e ornmentl species nd cn e used in lndscpe grdening. Due to its rpid growth, D. urntic cn dpt to open res nd is used in heterogeneous re-foresttion (LORENZI, 08; POTT; POTT, 1994). Becuse of the lck of studies concerning the germintion of Brzilin flor, prticulrly with respect to understnding of the iology nd ecology of ntive plnts in rod-leved, semi-deciduous svnnhs, the ojective of this reserch ws to evlute the effects of temperture on seed germintion nd the initil growth of the primry root of Diptychndr urntic. of August 10. Mture, dried fruits were collected from trees using trimmer, stored in Krft pper gs nd trnsported to the Lortory of Reserch into Bio-diversity nd Environmentl Systems t Anhnguer-Uniderp University in Cmpo Grnde. In the lortory, dmged/collpsed nd insectttcked seeds were eliminted, nd moisture content test ws conducted to determine the percentge of wter in the seeds following previously pulished procedure (BRASIL, 09). The seeds selected for germintion testing were immersed in sodium hypochlorite solution (2%) for three minutes nd susequently wshed in tp wter for one minute. To evlute the effect of temperture on germintion, totl of 600 seeds were exposed to constnt tempertures of, 25, nd 35 C nd lternting tempertures of - nd C, with four replictions of 25 seeds per tretment under 12-hour photoperiod with white light in B.O.D. germintion chmers. The tests were conducted in trnsprent oxes (11 x 11 x 3.5 cm) over two sheets of germitest pper towels tht hd previously een humidified with 0.1% (m v -1 ) Rovrl fungicide. Germintion ws evluted dily for period of 12 dys, strting from the first dy fter sowing. The seeds were considered to hve germinted when the primry root protrusion ttined minimum length of 2 mm. The seedlings from the germintion tests (100% of the seedlings for ech temperture) were exmined to determine the verge length nd dry iomss of the primry roots. The primry root length ws expressed in millimetres (mm) with the id of digitl pquimeter. Sections of the seedlings were dissected using sclpel, crefully plced into the designted pper gs, trnsferred to ventilted greenhouse nd mintined t 80 C for 24 hours, fter which the primry roots were individully weighed on nlyticl scles (the men weights re given in g). The germintion percentge (G) ws evluted together with the germintion speed index (GSI) nd the verge germintion time (AGT). The germintion percentge dt were converted using n rc-sine (x/100) 0,5 function. The dt were nlysed with Bioestt 4.0 sttisticl softwre (p 0.05), nd the mens were compred using Tukey s test (p < 0.05). Mteril nd methods Diptychndr urntic fruits were collected from woodlnds in the Toco region of the municiplity of Corguinho (19 49 S O, 3 m ltitude) in the stte of Mto Grosso do Sul during the month Results nd discussion The Diptychndr urntic seeds contined 7.6% wter, within the 5-% rnge found in the mjority of plnt species (BEWLEY; BLACK, 1994), with few exceptions, including reclcitrnt seeds.

3 Germintion of Diptychndr urntic (Fcee) seeds 5 Germintion occurred under ll tretments (Tle 1), nd the rte of germintion ws higher t constnt tempertures. However, t the highest temperture (35 C), germintion decresed, thus demonstrting tht this temperture is not optiml for the germintion of D. urntic seeds. Using the sme species, Lorenzi (08) demonstrted tht the germintion percentge is low when seeds re sown using n orgnic cly sustrte, with plnts eing oserved to emerge within two to three weeks under these conditions. Nevertheless, in the lortory, germintion ws initited within four to eight dys of the initition of the experiment, depending on the temperture. The results indicted tht the germintion percentge ws greter thn 60% under, 25,, - nd C tempertures. Tle 1. Averge germintion percentge (G%), germintion speed index (GSI) nd verge germintion time (AGT) of Diptychndr urntic t six different tempertures. Temperture ( C) G (%) GSI AGT (dys) 72 c c e 0.5 c 10.1 c - 77 c d 0.74 c 8.9 Vlues followed y the sme letter in column do not differ sttisticlly from ech other sed on Tukey s test (p > 0.05). Constnt tempertures of 25 nd ºC promoted the highest verge germintion rtes nd resulted in the highest vlues for the GSI, indicting tht these tempertures promote rpid stnd estlishment. At temperture of - C, germintion ws lso incresed, lthough t lower rte. The lowest AGT ws otined with tempertures of nd - C. Slow-germinting seeds cn result from fungl ttck during wter imiition, even resulting in filure to germinte. Therefore, seeds exhiiting the fstest germintion speeds re less ffected y pthogen ttcks (SCREMIN-DIAS et l., 06); thus, fster germintion is etter. Tempertures of nd 35 C negtively ffected the percentge nd speed (AGT nd GSI) of germintion, showing tht these tempertures were indequte for germintion in this species. Alternting tempertures of - nd C hd similr effects, resulting in lower rtes of germintion, while t tempertures etween nd C, the germintion speed (GSI nd AGT) ws high (Tle 1). Figure 1 shows the ccumulted germintion rtes of D. urntic seeds during the 12 dys of the experiment. At C, germintion ws positively ffected, resulting in the highest vlues of the studied prmeters, with germintion occurring prior to the sixth dy fter sowing nd reching 87% y the end of the experiment under this temperture. At the 25 C, germintion occurred on the eighth dy fter sowing, reching 97% fter 12 dys. Accumulted (%) Acumulted germintion (%) Dys Dys Temperture Figure 1. Accumulted germintion (%) mong Diptychndr urntic seeds cultivted t four constnt tempertures nd two lternting tempertures in B.O.D chmer. In ccordnce with Crvlho nd Nkgw (00), tempertures ove or elow the optimum temperture tend to reduce the speed of germintion, exposing seedlings to longer periods in less fvourle environments. This incresed exposure to unfvourle environments could led to decrese in the germintion percentge, in this study, t nd 35 C. These tempertures re therefore elow nd ove optimum, respectively; oth of these tempertures resulted in reduced germintion speed. Vrious uthors, including Cssro-Silv (01) studying Senn mcrnther (Colld.) Irwin & Brn., Cetnrski Filho nd Nogueir (05) investigting Ocote odorifer (Vellozo) Rohwer nd Oliveir et l. (05) using Teui impetiginos (Mrtius ex A. P. de Cndolle), Stndley nd T. serrtifoli Vhl Nich., hve demonstrted tht the optimum temperture flls within rnge of 25 to ºC. Cstro et l. (04) suggested tht the energy of wter increses in response to the elevtion of temperture, provoking n increse in diffusion pressure, which concomitntly elevtes the metolic ctivity nd diminishes the internl potentil of seed, promoting incresed sorption of wter. Thus, hydrtion occurs more rpidly t higher tempertures through physicl processes tht could ccelerte germintion. Germintion ws oserved t constnt tempertures of up to C. However, t 35 C, germintion ws reduced, perhps s consequence of dmge to the seed structure. Higher tempertures could potentilly lter enzymtic ctivity nd reduce the quntity of mino cids ville (vi RNA synthesis), therey modifying metolic rections tht reduce emryo

4 6 Oliveir et l. development nd restrict seed germintion, s reported y Lrcher (03), Mrcos Filho (05) nd Tiz nd Zeiger (09). Cssro-Silv (01) studied the enthlpy of germintion in S. mcrnther seeds nd reported tht t super-optimum or extremely high tempertures, the energy contined in the cells or the cellulr memrnes of seeds lwys remins less fvourle for emryonic growth until reching mximum temperture t which ll of the energy is dissipted. At this point, iochemicl processes tht limit germintion occur, such s fusion, evportion of sustnces nd denturtion of proteins. As consequence, ll enzyme-medited processes re temporrily interrupted or cese completely until the system is re-estlished. A reduction in the rte of metolic rections could occur t temperture of C, ffecting the essentil processes tht initite germintion. Thus, low environmentl tempertures could result in the estlishment of fewer seedlings nd reduction of iomss, prticulrly mong tropicl nd sutropicl species. The extent of the dmge incurred depends on the species, the initil wter content of the seed, the temperture nd the length of exposure time (CARVALHO; NAKAGAWA, 00; FERREIRA; BORGHETTI, 04; TAIZ; ZEIGER, 09), therey reducing the speed nd percentge of germintion nd incresing the verge time period required for germintion. This process might e ttriuted to chemicl chrcteristics, such s the rtes of proline nd ftty cid synthesis (CASSARO- SILVA, 01), or the dectivtion of enzymes (CASSARO-SILVA, 01). Lrcher (03) suggested tht the optimum temperture for species in tropicl res typiclly rnges from to 35ºC, which is the most fvourle temperture rnge for the development of mny plnts in terms of seed germintion, growth nd flowering, mong other processes. According to Cssro-Silv (01), the speed of germintion is directly dependent on temperture. Silv nd Aguir (04), using Cnidosculus phyllcnthus [Px & K. Hoffm], nd Lopes et l. (05), studying Bsell rur L., hve suggested tht ltertions in temperture could fcilitte etter conditions for germintion. Bskin nd Bskin (01) emphsised tht seeds tht respond to lternting tempertures exhiit enzymtic mechnisms tht function t different tempertures in response to ecologicl dpttions to the environment. For seeds of the D. urntic tree, lternting tempertures were less fvourle for germintion compred with constnt tempertures etween 25 nd C; however, the seeds produced t tempertures of - C were similr in speed. The results of this study indicte tht the minimum temperture for the germintion of D. urntic seeds lies etween 10 nd 15 C, while the mximum temperture is etween 40 nd 45 C. Notly, tempertures of to 35 C were not found to e the most pproprite tempertures for germintion. Figure 2 shows the dily reltive frequency of germintion, indicting tht the pek of germintion, for most tempertures, occurred etween the seventh nd tenth dys. However, germintion commenced erlier under lternting tempertures nd t constnt temperture of C (on the 4 th dy t C nd 5 th dy t C or - C). Frequency of germintion (%) Frequency of germintion (%) Dys Temperture ( C) Figure 2. Reltive dily frequency of germintion in Diptychndr urntic seeds cultivted t four constnt tempertures nd two lternting tempertures. Diptychndr urntic is typiclly found in res of secondry succession nd in res exposed to light. While stndrd does not exist, it is generlly ccepted tht plnts in these res disply high rtes of germintion nd growth, representing pioneering species, which tend to exhiit higher tolernce in these res nd, s consequence, germinte nd grow more rpidly. Temperture is therefore n importnt fctor in the germintion of D. urntic seeds, influencing the totl germintion, strength nd speed of germintion. Experiments performed y Crvlho nd Nkgw (00) showed tht temperture is indeed fctor tht ffects the germintion process. Primry root lengths of 17.5 nd 16.5 mm were recorded t tempertures of 25 nd C, respectively, with no significnt differences. However, the primry root lengths were sttisticlly significntly different under the other tretments, verging 12.3 mm t C, 11.1 mm t 35 C, nd 13.0 mm t tempertures of - nd C; these lengths were ll sttisticlly equl to ech other (Figure 3).

5 Germintion of Diptychndr urntic (Fcee) seeds 7 Length (mm) c Tempertures (oc) (ºC) Figure 3. Averge length of primry roots (mm) of Diptychndr urntic cultivted t different tempertures. Averge lengths followed y the sme letter were not significntly different when sujected to Tukey s test (p > 0.05). Rosseto et l. (09) oserved n verge length of 4 cm for the primry roots of Prki pendul (Willd.), Benth. ex Wlp., suggesting tht temperture of C ws lso more pproprite for the initil growth of the primry root in this species. Oliveir et l. (11) oserved n verge length of.6 (25 o C) nd 23.5 ( o C) for primry roots of Aspidosperm tomentosum Mrt., pproprite for the initil growth nd similr the this work. Primry root growth is generlly oserved to occur within wide temperture rnge, vrying y t lest 2 to 5ºC for ligneous species cultivted within temperte zones, nd t tempertures ove 10ºC for plnts in tropicl regions (LARCHER, 03). The optimum temperture for cell division is pproximtely ºC for the mjority of species, which is therefore ner the optimum temperture for growth (FERREIRA; BORGHETTI, 04). The highest vlues with respect to the ccumultion of dry iomss in the primry roots were oserved t tempertures of C ( g), 25 C ( g) nd C ( g), with the other exmined tempertures resulting in iomss vlues of g (35 C) nd g (- nd C), less iomss (Figure 4). Dry Dry io-mss (g) (g) , , , , , , , , Tempertures (oc) (ºC) Figure 4. Averge dry iomss (g) of the primry roots of Diptychndr urntic cultivted t different tempertures (verges followed y the sme letter did not differ sttisticlly when sujected to Tukey s test; p > 0.05). c Tken together, these dt confirm tht temperture of 25 C is the most suitle temperture for seed germintion nd the initil development (primry roots), producing seedlings tht re on verge etter le to dpt within smller time frme. Brnclion et l. (10) lso stted tht temperture of 25 C is pproprite for conducting germintion tests in species from cerrdo/svnnh iome. The next est temperture is C, which lso results in the highest rte nd strength of germintion nd well-formed primry roots. Conclusion Tempertures of 25 nd C provided the most fvourle conditions for germintion nd initil primry root growth in D. urntic seeds. Acknowledgements The uthors would like to thnk the University of Anhnguer-Uniderp for finncing the GIP project ( Interdisciplinry Reserch Group ) nd for the PIC scholrship. We would lso like to thnk the Ntionl Council for Scientific nd Technologicl Development (CNPq) for the strt-up scholrship (PIBIC) to Rieiro nd the present reserch grnt (PQ2) to Oliveir. References BASKIN, C. C.; BASKIN, J. M. Seeds: ecology, iogeogrphy, nd evolution of dormncy nd germintion. Sn Diego: Acdemic Press, 01. BEWLEY, J. D.; BLACK, M. Seeds: physiology of development nd germintion. 2nd ed. New York/London: Plenum Press, BRANCALION, P. H. S.; NOVEMBRE, A. D. L. C.; RODRIGUES, R. R. Tempertur ótim de germinção de sementes de espécies róres rsileirs. Revist Brsileir de Sementes, v. 32, n. 4, p , 10. BRASIL. Ministério d Agricultur, Pecuári e Astecimento. Regrs pr nálise de sementes. Brsíli: Secretri de Defes Agropecuári. Mp/ACS, 09. CARVALHO, N. M.; NAKAGAWA, J. Sementes: ciênci, tecnologi e produção. 4. ed. Joticl: Funep, 00. CASSARO-SILVA, M. Efeito d tempertur n germinção de sementes de mnduirn (Senn mcrnther (Colld.) Irwin et Brn. - Ceslpinicee). Revist Brsileir de Sementes, v. 23, n. 1, p , 01. CASTRO, R. D.; BRADFORD, K. J.; HILHORST, H. W. M. Emeição e retivção do metolismo. In: FERREIRA, A. G.; BORGHETTI, F. (Org.). Germinção: do ásico o plicdo. Porto Alegre: Artmed, 04. p

6 8 Oliveir et l. CETNARSKI FILHO, R.; NOGUEIRA, A. C. Influênci d tempertur n germinção de diásporos de Ocote odorifer (Vellozo) Rohwer (Cnel-Sssfrás). Ciênci Florestl, v. 15, n. 2, p , 05. FERREIRA, A. G.; BORGHETTI, F. Germinção: do ásico o plicdo. Porto Alegre: Artmed, 04. LARCHER, W. Physiologicl plnt ecology: ecophysiology nd stress physiology of functionl groups. Berlin: Springer, 03. LOPES, J. C.; CAPUCHO, M. T.; MARTINS FILHO, S.; REPOSSI, P. A. Influênci de tempertur, sustrto e luz n germinção de sementes de Bertlh. Revist Brsileir de Sementes, v. 27, n. 2, p , 05. LORENZI, H. Árvores rsileirs: mnul de identificção e cultivo de plnts róres ntivs do Brsil. 5. ed. Nov Odess: Instituto Plntrum, 08. v. 1. MARCOS FILHO, J. Fisiologi de sementes de plnts cultivds. Pircic: Felq, 05. OLIVEIRA, A. K. M.; SCHLEDER, E. J.; FAVERO, S. Viilidde de sementes e recuperção de áres degrdds. In: BAUER, F. C.; VARGAS JÚNIOR, F. M. (Coord.). Produção e gestão groindustril. Cmpo Grnde: Uniderp, 05. p OLIVEIRA, A. K. M.; RIBEIRO, J. W. F.; PEREIRA, K. C. L.; SILVA, C. A. A. Germinção de sementes de Aspidosperm tomentosum Mrt. (Apocyncee) em diferentes temperturs. Revist Brsileir de Biociêncis, v. 9, n. 3, p , 11. OLIVEIRA, L. M.; CARVALHO, M. L. M.; SILVA, T. T. A.; BORGES, D. I. Tempertur e regime de luz n germinção de sementes de Teui impetiginos (Mrtius ex A. P. de Cndolle) Stndley e T. serrtifoli Vhl Nich. Bignonicee). Ciênci e Agrotecnologi, v. 29, n. 3, p , 05. POTT, A.; POTT, V. J. Plnts do Pntnl. Corumá: Emrp, ROSSETO, J.; ALBUQUERQUE, M. C. F.; RUBENS NETO, R. M.; SILVA, I. C. O. Germinção de sementes de Prki pendul (Willd.) Benth. ex Wlp. (Fcee) em diferentes temperturs. Revist Árvore, v. 33, n. 1, p , 09. SCREMIN-DIAS, E.; KALIFE, C.; MENEGUCCI, Z. R. H.; SOUZA, P. R. Produção de muds de espécies florestis ntivs: mnul. Cmpo Grnde: UFMS, 06. SILVA, L. M. M.; AGUIAR, I. B. Efeito dos sustrtos e temperturs n germinção de sementes de Cnidosculus phyllcnthus Px & K. Hoffm. (Fveleir). Revist Brsileir de Sementes, v. 26, n. 1, p. 9-14, 04. TAIZ, L.; ZEIGER E. Fisiologi vegetl. 4. ed. Porto Alegre: Artmed, 09. Received on Ferury 7, 12. Accepted on April 27, 12. License informtion: This is n open-ccess rticle distriuted under the terms of the Cretive Commons Attriution License, which permits unrestricted use, distriution, nd reproduction in ny medium, provided the originl work is properly cited.