Acessibilidade / Reportar erro

Salt stress and temperatures on the germination and initial growth of ‘jurema-de-embira’ (Mimosa ophthalmocentra) seedlings

Estresse salino e temperaturas na germinação e crescimento inicial de jurema-de-embira (Mimosa ophthalmocentra)

ABSTRACT

The objective of this study was to evaluate the effects of salinity on the germination and initial growth of ‘jurema-de-embira’ (Mimosa ophthalmocentra) seedlings at different temperatures. The experiment was installed in a completely randomized design, in a factorial scheme of eight salt concentrations (0; 4.0; 8.0; 12.0; 16.0; 20.0; 24.0 and 28.0 dS m-1) and four temperatures (25, 30, 35 and 20-30 °C) in four replicates of 25 seeds under an 8-h photoperiod in Biochemical Oxygen Demand germinators. The variables analyzed were: germination, germination speed index, shoot and root lengths, and shoot, root and total dry matter. Temperature variation influences the response of ‘jurema-de-embira’ seeds to salinity, and the salt stress is intensified by the increase in temperature. ‘Jurema-de-embira’ is tolerant to salt stress in the germination stage, showing satisfactory germination up to the salinity level 20 dS m-1, at temperatures below 30 °C. The initial growth of ‘jurema-de-embira’ plants is satisfactory up to salinity of 12 dS m-1, at temperatures below 30 °C.

Key words:
Fabaceae; forest species; caatinga; salinity

RESUMO

Objetivou-se com esse trabalho avaliar os efeitos da salinidade sobre a germinação e crescimento inicial de plântulas de jurema-de-embira (Mimosa ophthalmocentra) em diferentes temperaturas. O experimento foi instalado em delineamento inteiramente casualizado, em esquema fatorial de oito concentrações salinas (0; 4,0; 8,0; 12,0; 16,0; 20,0; 24,0 e 28,0 dS m-1) e quatro temperaturas (25, 30, 35 e 20-30 °C), em quatro repetições de 25 sementes, sob fotoperíodo de 8 h em germinadores do tipo Biochemical Oxygen Demand. As variáveis analisadas foram germinação, índice de velocidade de germinação, comprimento da parte aérea e da raiz, massa seca da parte aérea, raiz e total. A variação da temperatura influencia a resposta das sementes de jurema-de-embira à salinidade, sendo o estresse salino potencializado pelo aumento das temperaturas. A jurema-de-embira é tolerante na fase de germinação ao estresse salino, apresentando germinação satisfatória até o nível de salinidade 20 dS m-1, em temperaturas inferiores a 30 °C. O crescimento inicial das plantas de jurema-de-embira é satisfatório até a salinidade de 12 dS m-1, em temperaturas inferiores a 30 °C.

Palavras-chave:
Fabaceae; espécie florestal; caatinga; salinidade

Introduction

‘Jurema-de-embira’ (Mimosa ophthalmocentra Mart. ex Benth.) is a species with high potential for wood production (Figueirôa et al., 2005Figueirôa, J. M.; Pareyn, F. G. C.; Drumond, M.; Araújo, E. L. Madeireiras. In: Sampaio, E. V. S. B (ed.). Espécies da flora nordestina de importância econômica potencial. Recife: Associação Plantas do Nordeste (APNE), 2005. Cap.6, p.101-133.), native to the Caatinga biome (Cavalcanti et al., 2009Cavalcanti, A. D. C.; Rodal, M. J. N.; Sampaio, E. V. S. B.; Costa, K. C. C. Mudanças florísticas e estruturais, após cinco anos, em uma comunidade de caatinga no estado de Pernambuco, Brasil. Acta Botânica Brasílica, v.23, p.1210-1212, 2009. https://doi.org/10.1590/S0102-33062009000400032
https://doi.org/10.1590/S0102-3306200900...
), which is also found in riparian forest areas (Lacerda et al., 2007Lacerda, A. V.; Barbosa, F. M.; Barbosa, M. R. V. Estudo do componente arbustivo-arbóreo de matas ciliares da bacia do rio Taperoá, semiárido paraibano: Uma perspectiva para a sustentabilidade dos recursos naturais. Oecologia Brasiliensis, v.11, p.331-340, 2007. https://doi.org/10.4257/oeco.2007.1103.03
https://doi.org/10.4257/oeco.2007.1103.0...
) and in regeneration areas (Sampaio et al., 2010Sampaio, E.; Gasson, P.; Baracat, A.; Cutler, D.; Pareyn, F.; Lima, K. C. Tree biomass estimation in regenerating areas of tropical dry vegetation in northeast Brazil. Forest Ecology and Management, v.259, p.1135-1140. 2010. https://doi.org/10.1016/j.foreco.2009.12.028
https://doi.org/10.1016/j.foreco.2009.12...
). As occurs for the other species of the Caatinga, there is little agronomic information on M. ophthalmocentra, especially regarding its propagation (Lima et al., 2006Lima, J. D.; Almeida, C. C.; Dantas, V. A. V.; Silva, B. M. S.; Moraes, W. Efeito da temperatura e dos substratos na germinação de sementes de Caesalpinia ferrea Mart. ex. Tul. (Leguminosae). Revista Árvore, v.30, p.513-518, 2006. https://doi.org/10.1590/S0100-67622006000400003
https://doi.org/10.1590/S0100-6762200600...
). Among the factors responsible for limiting its propagation in semiarid regions, soil salinity and high temperatures stand out, responsible for reducing germination and plant development (Sá et al., 2013Sá, F. V. S.; Araújo, J. L.; Novais, M. C.; Silva, A. P.; Pereira, F. H. F.; Lopes, K. P. Crescimento inicial de arbóreas nativas em solo salinosódico do Nordeste brasileiro tratado com acondicionadores. Revista Ceres, v.60, p.388-396, 2013. https://doi.org/10.1590/S0034-737X2013000300012
https://doi.org/10.1590/S0034-737X201300...
; Souza, 2013Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado).

Among the methods to determine plant tolerance to salt stress, the evaluation of germination and initial growth in saline substrate is one of the most widespread (Lima & Torres, 2009Lima, B. G.; Torres, S. B. Estresses hídrico e salino na germinação de sementes de Zizyphus joazeiro Mart. (Rhamnaceae). Revista Caatinga, v.22, p.93-99, 2009.). Good germination indices under salt stress conditions is an indication of tolerance to the stress (Sá et al., 2016Sá, F. V. S.; Paiva, E. P.; Torres, S. B.; Brito, M. E. B.; Nogueira, N. W.; Frade, L. J. G.; Freitas, R. M. O. Seed germination and vigor of different cowpea cultivars under salt stress. Comunicata Scientiae, v.7, p.450-455, 2016. https://doi.org/10.14295/cs.v7i4.1541
https://doi.org/10.14295/cs.v7i4.1541...
). Temperature variations affect germination speed, percentage and uniformity (Marcos Filho, 2015Marcos Filho, J. Fisiologia de sementes de plantas cultivadas. Londrina: ABRATES, 2015. 659p.), and optimal temperature is the one at which the combination of these variables is most efficient.

Some studies have been carried out to investigate the tolerance to salt stress as a function of temperature variations, such as Galindo (2010)Galindo, E. A. Tecnologia de sementes de Crataeva tapia L. Areia: Centro de Ciências Agrárias/Universidade Federal da Paraíba, 2010. 92p. Dissertação Mestrado, with Crataeva tapia; Guedes et al. (2011)Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
https://doi.org/10.1590/S0101-3122201100...
, with Chorisia glaziovii and Souza (2013)Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado, with Swetenia macrophylla and Enterolobium contortisiliquum. Effects of salinity have also been observed by Lima & Torres (2009)Lima, B. G.; Torres, S. B. Estresses hídrico e salino na germinação de sementes de Zizyphus joazeiro Mart. (Rhamnaceae). Revista Caatinga, v.22, p.93-99, 2009., on Zizyphus joazeiro; Barreto et al. (2010)Barreto, H. B. F.; Freitas, R. M. O.; Oliveira, L. A. A.; Araújo, J. A. M.; Costa, E. M. Efeito da irrigação com água salina na germinação de sementes de sábia (Mimosa caesalpiniifolia Benth). Revista Verde de Agroecologia e Desenvolvimento Sustentável, v.5, p.125-130, 2010., on Mimosa caesalpiniifolia; Freitas et al. (2010)Freitas, R. M. O.; Nogueira, N. W.; Oliveira, F. N.; Costa, E. M.; Ribeiro, M. C. C. Efeito da irrigação com água salina na emergência e crescimento inicial de plântulas de Jucá. Revista Caatinga, v.23, p.54-58, 2010., on Caesalpinia ferrea; Nogueira et al. (2012)Nogueira, N. W.; Lima, J. S. S.; Freitas, R. M. O.; Ribeiro, M. C. C.; Leal, C. C. P.; Pinto, J. R. S. Efeito da salinidade na emergência e crescimento inicial de plântulas de flamboyant. Revista Brasileira de Sementes, v.34, p.466-472, 2012. https://doi.org/10.1590/S0101-31222012000300014
https://doi.org/10.1590/S0101-3122201200...
, on Delonix regia; Guimarães et al. (2013)Guimarães, I. P.; Oliveira, F. N.; Vieira, F. E. R.; Torres, S. B. Efeito da salinidade da água de irrigação na emergência e crescimento inicial de plântulas de mulungu. Revista Brasileira de Ciências Agrárias, v.8, p.137-142, 2013. https://doi.org/10.5039/agraria.v8i1a2360
https://doi.org/10.5039/agraria.v8i1a236...
, on Erythrina vellutina and Lima et al. (2015)Lima, M. F. P.; Porto, M. A. F.; Torres, S. B.; Freitas, R. M. O.; Nogueira, N. W.; Carvalho, D. R. Emergência e crescimento inicial de plântulas de albízia submetidas à irrigação com água salina. Revista Brasileira de Engenharia Agrícola e Ambiental, v.19, p.3-8, 2015. https://doi.org/10.1590/1807-1929/agriambi.v19n2p106-112
https://doi.org/10.1590/1807-1929/agriam...
, on Albizia lebbeck, in which increasing salinity negatively affected germination and initial development of seedlings.

In this context, the objective was to evaluate the effects of salinity on germination and initial development of M. ophthalmocentra seedlings at different temperatures.

Material and Methods

‘Jurema-de-embira’ seeds were obtained from ripe fruits (pods) of 25 plants located in the municipality of Mossoró, RN (5o 11' 15' S; 37o 20' 39'' W; 16 m). After collection, the seeds were manually removed, cleaned and dried in the shade. Then, they were fumigated, placed in cans and maintained in cold and dry chamber (15 °C and 50% of ambient RH) until the evaluations.

The statistical design was completely randomized, in 4 x 8 factorial scheme (temperatures x salinity levels), and each treatment was composed of four replicates of 25 seeds.

Because these seeds have integumentary dormancy, their tips were cut using scissors on the end opposite to the hilum and planted on Germitest paper towel sheets moistened with saline solutions, in volume equivalent to 2.5 times the dry paper weight, produced with the addition of sodium chloride in distilled water until obtaining the preestablished salinity levels of 0, 4, 8, 12, 16, 20, 24 and 28 dS m-1, measured using a digital conductivity meter.

Germination tests were carried out in Biochemical Oxygen Demand (BOD) germinators, regulated at constant temperatures of 25, 30 and 35 °C, and alternated temperature of 20-30 ºC (8/16 h), with 8-h photoperiod. Seeds were daily evaluated until 7 days after sowing and were considered as germinated when they produced the primary root and healthy seedling shoots (Brasil, 2009Brasil. Ministério da Agricultura, Pecuária e Abastecimento. Regras para análise de sementes. Ministério da Agricultura, Pecuária e Abastecimento. Secretaria de Defesa Agropecuária. Brasília: MAPA/ACS, 2009. 399p.).

The variables analyzed were: a) germination percentage - expressed in percentage of normal seedlings; b) germination speed index - measured simultaneously to the germination test, in which seedlings were daily evaluated from the beginning of germination to 7 days after sowing, and the index was calculated according to the equation proposed by Maguire (1962)Maguire, J. D. Speed of germination-aid in selection and evaluation for seedling emergence and vigor. Crop Science, v.2, p.176-177, 1962. https://doi.org/10.2135/cropsci1962.0011183X000200020033x
https://doi.org/10.2135/cropsci1962.0011...
; c) shoot and root lengths - after the germination test, all normal seedlings of the experimental unit were measured for root length (plant base to root tip) and shoot (plant base to insertion of cotyledons) using a ruler graduated in centimeters; d) dry matter of shoots, roots and total - all normal seedlings of the experimental unit were separated into roots and shoots, dried in a forced-air oven at 65 ºC until constant weight (48 h) and weighed on precision analytical scale (0.001 g). Total dry matter was obtained by the sum of root dry matter and shoot dry matter.

The results were subjected to analysis of variance by F test at 0.05 probability level, using the statistical program SISVAR® (Ferreira, 2014Ferreira, D. F. Sisvar: A guide for its bootstrap procedures in multiple comparisons. Ciência e Agrotecnologia, v.38, p.109-112, 2014. https://doi.org/10.1590/S1413-70542014000200001
https://doi.org/10.1590/S1413-7054201400...
). In case of significance, the data were subjected to regression analysis using the software SigmaPlot®. The model was selected based on the biological explanation and significance of the regression mean square.

Results and Discussion

The interaction between salt concentrations and temperatures had significant influence (p < 0.05) on all variables studied, except root dry matter, which was significantly influenced by the isolated factors (Table 1 and Figures 1, 2, 3). Increment in salinity reduced the germination of ‘juremade-embira’ seeds, and the salinity level causing reduction in germination decreased as temperature increased, being equal to 20.0, 16.0, 12.0 and 8.0 dS m-1 for the temperatures of 20-30, 25, 30 and 35 ºC, respectively. Salt stress intensely affected the germination of ‘jurema-de-embira’ seeds at temperature of 35 ºC (Figure 1A), leading to null germination at the highest salinity level (28 dS m-1). This result occurs because high temperatures accelerate respiration and, consequently, increase water requirement, which is reduced due to the low osmotic potential of the substrate, thus resulting in seed deterioration (Guedes et al., 2011Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
https://doi.org/10.1590/S0101-3122201100...
), inducing the reduction in germination and/or increase in the formation of abnormal seedlings and dead seeds.

Table 1
Means of root dry matter (RDM) of ‘jurema-deembira’ seedlings subjected to different temperatures

Figure 1
Percentage of normal seedlings (A) and germination speed index - GSI (B) of ‘jurema-de-embira’ seeds, subjected to salt stress at different temperatures

Figure 2
Shoot length - SL (A) and root length - RL (B) of ‘jurema-de-embira’ seedlings subjected to salt stress at different temperatures

Figure 3
Root dry matter - RDM (A), shoot dry matter - SDM (B) and total dry matter - TDM (C) of ‘jurema-de-embira’ seedlings subjected to salt stress at different temperatures

The temperatures of 20-30 and 25 ºC caused less drastic effects, and the reduction in germination percentage (formation of normal seedlings) occurred from 20 and 16 dS m-1, but the most harmful effects occurred from the salinity level of 24 dS m-1, with reductions of 40.25 and 57.45%, respectively (Figure 1A). Hence, seeds subjected to the lowest temperatures (20- 30 and 25°C) showed lower respiration rate and lower water requirement, reducing the effects of the osmotic potential.

Under saline conditions, temperature variation has different effects on germination according to the species. Some seeds maintain their germination capacity after exposure to salinity (Khan & Ungar, 1997Khan, M. A.; Ungar, I. A. Effect of light, salinity, and thermoperiod on the seed germination of halophytes. Canadian Journal of Botany, v.75, p.835-841, 1997. https://doi.org/10.1139/b97-093
https://doi.org/10.1139/b97-093...
). Thus, the interaction between temperature and salinity during germination plays an important role in determining the response to this process and a successful establishment in saline habitats (Ungar, 1995Ungar, I. A. Seed germination and seed-bank ecology of halophytes. In: Kiegel, J.; Galili, G. (org.). Seed development and germination. New York: Marcel and Dekker Inc., 1995. Chap.23, p.599-628.).

Greater reduction in the germination percentage of seeds subjected to salt stress at temperature of 35 ºC has also been observed by Galindo (2010)Galindo, E. A. Tecnologia de sementes de Crataeva tapia L. Areia: Centro de Ciências Agrárias/Universidade Federal da Paraíba, 2010. 92p. Dissertação Mestrado, in C. tapia; Guedes et al. (2011)Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
https://doi.org/10.1590/S0101-3122201100...
, in C. glaziovii and Souza (2013)Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado, in S. macrophylla and E. contortisiliquum. According to Guedes et al. (2011)Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
https://doi.org/10.1590/S0101-3122201100...
, higher temperature (35 °C) can cause disintegration of protein structures and, along with the toxic effect and physiological drought caused by the levels of salts, led to reduction in seed germination.

The increase in salinity reduced germination speed, but in different ways for the temperatures studied (Figure 1B). Highest and lowest germination speeds were found in seeds maintained at temperature of 35 ºC, at salinity levels of 0 and 28 dS m-1, respectively. It demonstrates that, although high temperatures accelerate metabolic processes in stressful situations (water deficit induced by the excess of salts), they tend to intensify the effects of salt stress on seed germination (Figure 1B).

At high temperatures, the speed of metabolic processes increases, shortening the duration of phase II in the soaking process. According to Nascimento (2005)Nascimento, W. M. Condicionamento osmótico de sementes de hortaliças visando a germinação em condições de temperaturas baixas. Horticultura Brasileira, v.23, p.211-214, 2005. https://doi.org/10.1590/S0102-05362005000200010
https://doi.org/10.1590/S0102-0536200500...
, very low or very high temperatures can alter both speed and final percentage of germination. Usually, low temperatures reduce germination speed, while high temperatures increase it. Reductions in GSI with the increment in salinity have also been observed by Galindo (2010)Galindo, E. A. Tecnologia de sementes de Crataeva tapia L. Areia: Centro de Ciências Agrárias/Universidade Federal da Paraíba, 2010. 92p. Dissertação Mestrado, in C. tapia; Guedes et al. (2011)Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
https://doi.org/10.1590/S0101-3122201100...
, in C. glaziovii and Souza (2013)Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado in S. macrophylla and E. contortisiliquum.

Increased water salinity severely affected shoot length and root length in ‘jurema-de-embira’ seedlings. The reduction in the shoots was more noticeable at temperatures of 35 and 20-30 ºC from the salinity level of 8.0 dS m-1 and, for root length, at temperatures of 25 and 30 ºC from 4.0 dS m-1 (Figures 2A and B). It can be pointed out that, at temperatures of 25 and 30 ºC, plants invest more in shoot growth and, consequently, this part develops more than the root system. This is an important mechanism of plant tolerance to salinity, which aims to reduce root surface and, therefore, decrease the entry of water and ions in the plant, increasing the selectivity and reducing the risk of toxicity by specific ions (Esteves & Suzuki, 2008Esteves, B. S.; Suzuki, M. S. Efeito da salinidade sobre as plantas. Oecologia Brasiliensis, v.12, p.662-679, 2008. https://doi.org/10.4257/oeco.2008.1204.06
https://doi.org/10.4257/oeco.2008.1204.0...
; Muns & Tester, 2008Munns, R.; Tester, M. Mechanism of salinity tolerance. Annual Review of Plant Biology, v.59, p.651-681, 2008. https://doi.org/10.1146/annurev.arplant.59.032607.092911
https://doi.org/10.1146/annurev.arplant....
; Sá et al., 2016Sá, F. V. S.; Paiva, E. P.; Torres, S. B.; Brito, M. E. B.; Nogueira, N. W.; Frade, L. J. G.; Freitas, R. M. O. Seed germination and vigor of different cowpea cultivars under salt stress. Comunicata Scientiae, v.7, p.450-455, 2016. https://doi.org/10.14295/cs.v7i4.1541
https://doi.org/10.14295/cs.v7i4.1541...
). On the other hand, seeds germinated at temperature of 35 ºC obtained greater root development compared with the shoots, which denotes that plants under water deficit conditions induced by saline and thermal stress use their energy in the development of the root system in the search for water. In general, shoots tend to grow until water absorption by roots becomes limiting to growth; conversely, roots tend to grow until the demand for photosynthates, from the shoots, exceeds the supply (Taiz & Zeiger, 2013Taiz, L.; Zeiger, E. Fisiologia vegetal. 5.ed. Porto Alegre: Artmed, 2013. 954p).

Likewise, Guedes et al. (2011)Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
https://doi.org/10.1590/S0101-3122201100...
and Galindo (2010)Galindo, E. A. Tecnologia de sementes de Crataeva tapia L. Areia: Centro de Ciências Agrárias/Universidade Federal da Paraíba, 2010. 92p. Dissertação Mestrado found that the length of C. glaziovii and C. tapia L. seedlings, respectively, was affected as salinity levels increased, regardless of temperature. In contrast, Souza (2013)Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado observed that the growth of S. macrophylla and E. contortisiliquum seedlings was not sensitive to salinity.

For root dry matter, a decreasing linear response was found, with linear reductions of 0.0273 g for each unit increment in water salinity, regardless of the temperature at which seeds were germinated (Figure 3A). This reduction comprehends a total value of 67% comparing the results obtained at the lowest (0 dS m-1) and highest (28.0 dS m-1) levels of water electrical conductivity. For the temperatures, the dry matter accumulation in the roots of seedlings subjected to temperature of 35 ºC was lower than that of seedlings subjected to 25, 30 and 20-30 ºC (Table 1), thus denoting that the temperature of 35 ºC causes thermal stress on the germination of ‘juremade- embira’ seeds, and their optimal temperature is within the range from 20 to 30 ºC.

Under hydration with saline water at temperature of 20-30 °C, no expressive reductions were found in shoot dry matter and total dry matter until the salinity level of 28 dS m-1 (Figures 3B and C). At temperatures of 25 and 30 °C, these variables linearly decreased by 30 and 36% between the lowest (0 dS m-1) and highest (28.0 dS m-1) salinity levels. At temperature of 35 °C, shoot dry matter and total dry matter decreased after the estimated levels of 6.80 and 8.24 dS m-1, respectively. From these points on, drastic reductions occurred, with null dry matter accumulation at salinity of 28 dS m-1 (Figures 3B and C). Shoot dry matter and total dry matter curves are similar because roots represent a very small fraction of the total dry matter (less than 20%). Hence, the shoots determined the behavior of the curves.

A similar reduction in dry matter was observed by Galindo et al. (2010)Galindo, E. A. Tecnologia de sementes de Crataeva tapia L. Areia: Centro de Ciências Agrárias/Universidade Federal da Paraíba, 2010. 92p. Dissertação Mestrado in C. tapia seedlings, and total dry matter decreased as salinity increased. The greatest reduction was caused by the temperature of 35 ºC, while at 25 ºC there was almost no reduction in the total dry matter of the seedlings. Non-significant reductions in seedling dry matter as salinity increased were also observed by Souza (2013)Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado, in S. macrophylla and E. contortisiliquum.

Conclusions

  1. Temperature variation influences the response of ‘juremade-embira’ seeds to salinity, and the salt stress is intensified by its increase.

  2. ‘Jurema-de-embira’ is tolerant to salt stress in the germination stage, showing satisfactory germination until the salinity level of 16 dS m-1, at temperatures below 30 °C.

  3. The initial growth of ‘jurema-de-embira’ seedlings is satisfactory up to the salinity of 12 dS m-1, at temperatures below 30 °C.

Literature Cited

  • Barreto, H. B. F.; Freitas, R. M. O.; Oliveira, L. A. A.; Araújo, J. A. M.; Costa, E. M. Efeito da irrigação com água salina na germinação de sementes de sábia (Mimosa caesalpiniifolia Benth). Revista Verde de Agroecologia e Desenvolvimento Sustentável, v.5, p.125-130, 2010.
  • Brasil. Ministério da Agricultura, Pecuária e Abastecimento. Regras para análise de sementes. Ministério da Agricultura, Pecuária e Abastecimento. Secretaria de Defesa Agropecuária. Brasília: MAPA/ACS, 2009. 399p.
  • Cavalcanti, A. D. C.; Rodal, M. J. N.; Sampaio, E. V. S. B.; Costa, K. C. C. Mudanças florísticas e estruturais, após cinco anos, em uma comunidade de caatinga no estado de Pernambuco, Brasil. Acta Botânica Brasílica, v.23, p.1210-1212, 2009. https://doi.org/10.1590/S0102-33062009000400032
    » https://doi.org/10.1590/S0102-33062009000400032
  • Esteves, B. S.; Suzuki, M. S. Efeito da salinidade sobre as plantas. Oecologia Brasiliensis, v.12, p.662-679, 2008. https://doi.org/10.4257/oeco.2008.1204.06
    » https://doi.org/10.4257/oeco.2008.1204.06
  • Ferreira, D. F. Sisvar: A guide for its bootstrap procedures in multiple comparisons. Ciência e Agrotecnologia, v.38, p.109-112, 2014. https://doi.org/10.1590/S1413-70542014000200001
    » https://doi.org/10.1590/S1413-70542014000200001
  • Figueirôa, J. M.; Pareyn, F. G. C.; Drumond, M.; Araújo, E. L. Madeireiras. In: Sampaio, E. V. S. B (ed.). Espécies da flora nordestina de importância econômica potencial. Recife: Associação Plantas do Nordeste (APNE), 2005. Cap.6, p.101-133.
  • Freitas, R. M. O.; Nogueira, N. W.; Oliveira, F. N.; Costa, E. M.; Ribeiro, M. C. C. Efeito da irrigação com água salina na emergência e crescimento inicial de plântulas de Jucá. Revista Caatinga, v.23, p.54-58, 2010.
  • Galindo, E. A. Tecnologia de sementes de Crataeva tapia L. Areia: Centro de Ciências Agrárias/Universidade Federal da Paraíba, 2010. 92p. Dissertação Mestrado
  • Guedes, R. S.; Alves, E. U.; Galindo, E. A.; Barrozo, L. M. Estresse salino e temperaturas na germinação e vigor de sementes de Chorisia glaziovii O. Kuntze. Revista Brasileira de Sementes, v.33, p.279-288, 2011. https://doi.org/10.1590/S0101-31222011000200010
    » https://doi.org/10.1590/S0101-31222011000200010
  • Guimarães, I. P.; Oliveira, F. N.; Vieira, F. E. R.; Torres, S. B. Efeito da salinidade da água de irrigação na emergência e crescimento inicial de plântulas de mulungu. Revista Brasileira de Ciências Agrárias, v.8, p.137-142, 2013. https://doi.org/10.5039/agraria.v8i1a2360
    » https://doi.org/10.5039/agraria.v8i1a2360
  • Khan, M. A.; Ungar, I. A. Effect of light, salinity, and thermoperiod on the seed germination of halophytes. Canadian Journal of Botany, v.75, p.835-841, 1997. https://doi.org/10.1139/b97-093
    » https://doi.org/10.1139/b97-093
  • Lacerda, A. V.; Barbosa, F. M.; Barbosa, M. R. V. Estudo do componente arbustivo-arbóreo de matas ciliares da bacia do rio Taperoá, semiárido paraibano: Uma perspectiva para a sustentabilidade dos recursos naturais. Oecologia Brasiliensis, v.11, p.331-340, 2007. https://doi.org/10.4257/oeco.2007.1103.03
    » https://doi.org/10.4257/oeco.2007.1103.03
  • Lima, B. G.; Torres, S. B. Estresses hídrico e salino na germinação de sementes de Zizyphus joazeiro Mart. (Rhamnaceae). Revista Caatinga, v.22, p.93-99, 2009.
  • Lima, J. D.; Almeida, C. C.; Dantas, V. A. V.; Silva, B. M. S.; Moraes, W. Efeito da temperatura e dos substratos na germinação de sementes de Caesalpinia ferrea Mart. ex. Tul. (Leguminosae). Revista Árvore, v.30, p.513-518, 2006. https://doi.org/10.1590/S0100-67622006000400003
    » https://doi.org/10.1590/S0100-67622006000400003
  • Lima, M. F. P.; Porto, M. A. F.; Torres, S. B.; Freitas, R. M. O.; Nogueira, N. W.; Carvalho, D. R. Emergência e crescimento inicial de plântulas de albízia submetidas à irrigação com água salina. Revista Brasileira de Engenharia Agrícola e Ambiental, v.19, p.3-8, 2015. https://doi.org/10.1590/1807-1929/agriambi.v19n2p106-112
    » https://doi.org/10.1590/1807-1929/agriambi.v19n2p106-112
  • Maguire, J. D. Speed of germination-aid in selection and evaluation for seedling emergence and vigor. Crop Science, v.2, p.176-177, 1962. https://doi.org/10.2135/cropsci1962.0011183X000200020033x
    » https://doi.org/10.2135/cropsci1962.0011183X000200020033x
  • Marcos Filho, J. Fisiologia de sementes de plantas cultivadas. Londrina: ABRATES, 2015. 659p.
  • Munns, R.; Tester, M. Mechanism of salinity tolerance. Annual Review of Plant Biology, v.59, p.651-681, 2008. https://doi.org/10.1146/annurev.arplant.59.032607.092911
    » https://doi.org/10.1146/annurev.arplant.59.032607.092911
  • Nascimento, W. M. Condicionamento osmótico de sementes de hortaliças visando a germinação em condições de temperaturas baixas. Horticultura Brasileira, v.23, p.211-214, 2005. https://doi.org/10.1590/S0102-05362005000200010
    » https://doi.org/10.1590/S0102-05362005000200010
  • Nogueira, N. W.; Lima, J. S. S.; Freitas, R. M. O.; Ribeiro, M. C. C.; Leal, C. C. P.; Pinto, J. R. S. Efeito da salinidade na emergência e crescimento inicial de plântulas de flamboyant. Revista Brasileira de Sementes, v.34, p.466-472, 2012. https://doi.org/10.1590/S0101-31222012000300014
    » https://doi.org/10.1590/S0101-31222012000300014
  • Sá, F. V. S.; Araújo, J. L.; Novais, M. C.; Silva, A. P.; Pereira, F. H. F.; Lopes, K. P. Crescimento inicial de arbóreas nativas em solo salinosódico do Nordeste brasileiro tratado com acondicionadores. Revista Ceres, v.60, p.388-396, 2013. https://doi.org/10.1590/S0034-737X2013000300012
    » https://doi.org/10.1590/S0034-737X2013000300012
  • Sá, F. V. S.; Paiva, E. P.; Torres, S. B.; Brito, M. E. B.; Nogueira, N. W.; Frade, L. J. G.; Freitas, R. M. O. Seed germination and vigor of different cowpea cultivars under salt stress. Comunicata Scientiae, v.7, p.450-455, 2016. https://doi.org/10.14295/cs.v7i4.1541
    » https://doi.org/10.14295/cs.v7i4.1541
  • Sampaio, E.; Gasson, P.; Baracat, A.; Cutler, D.; Pareyn, F.; Lima, K. C. Tree biomass estimation in regenerating areas of tropical dry vegetation in northeast Brazil. Forest Ecology and Management, v.259, p.1135-1140. 2010. https://doi.org/10.1016/j.foreco.2009.12.028
    » https://doi.org/10.1016/j.foreco.2009.12.028
  • Souza, R. S. Potencial de espécies florestais nativas na fitoextração de sais. Cuiabá: Universidade Federal do Mato Grosso, 2013. 63p. Dissertação Mestrado
  • Taiz, L.; Zeiger, E. Fisiologia vegetal. 5.ed. Porto Alegre: Artmed, 2013. 954p
  • Ungar, I. A. Seed germination and seed-bank ecology of halophytes. In: Kiegel, J.; Galili, G. (org.). Seed development and germination. New York: Marcel and Dekker Inc., 1995. Chap.23, p.599-628.

Publication Dates

  • Publication in this collection
    Apr 2018

History

  • Received
    01 July 2017
  • Accepted
    22 Nov 2017
Departamento de Engenharia Agrícola - UFCG Unidade Acadêmica de Engenharia Agrícola, UFCG, Av. Aprígio Veloso 882, Bodocongó, Bloco CM, 1º andar, CEP 58429-140, Campina Grande, PB, Brasil, Tel. +55 83 2101 1056 - Campina Grande - PB - Brazil
E-mail: revistagriambi@gmail.com