The Copaifera langsdorffii Desf. seedlings, popularly known as “copaiba” or diesel tree, present a natural occurrence in the riparian forests of the Brazilian Cerrado, however, not much is known about their capacity...The Copaifera langsdorffii Desf. seedlings, popularly known as “copaiba” or diesel tree, present a natural occurrence in the riparian forests of the Brazilian Cerrado, however, not much is known about their capacity to recover from flooding, particularly when the focus is on their establishment and use in programs for the recovery of degraded areas near watercourses and subject to flooding. The objective of this study was to evaluate over time the recovery of the efficiency of the photosynthetic apparatus and the antioxidant activity of C. langsdorffii seedlings flooded during different periods. The pots with the seedlings were placed in a plastic tank and submerged with water, and were removed from the flood condition every 21 days (0, 21, 42, 63 and 84 days), and evaluated every 30 days (0, 30, 60, 90 and 120 days). The seedlings tolerated the flooding for up to 42 days, recovering after suspension of this condition. Seedlings flooded for 63 and 84 days showed lower recovery capacity after flooding, independently of the evaluation period. Under these conditions, lower efficiency of the photosynthetic apparatus, gas exchange, photo assimilate production and seedling quality were observed.展开更多
The Campomanesia adamantium is a threatened species from Brazil Savannah which seeds are desiccation-sensitive and do not withstand storage. This study aimed to reduce the sensitivity of Campomanesia adamantium seeds ...The Campomanesia adamantium is a threatened species from Brazil Savannah which seeds are desiccation-sensitive and do not withstand storage. This study aimed to reduce the sensitivity of Campomanesia adamantium seeds to desiccation using polyethylene glycol (PEG) and abscisic acid (ABA). Initially, seeds were subjected to PEG (0, -1.48, and -2.04 MPa) with or without ABA (100 μM) during 120 h, followed fast drying (silica gel) or slow drying (laboratory environment), at 20%, 15%, and 10% moisture content. In the second experiment, the seeds were PEG treated (-1.48 MPa) which provided the best results in the first experiment;the seeds were then subjected to different incubation times in PEG (30, 60, 90, or 120 h) and ABA (0, 10ˉ3, 10ˉ4, and 10ˉ5 μM), following the seeds were fast dried at 15% moisture content. The slow drying should be avoided, even in seeds previously subjected to osmotic conditioning with or without ABA. Seeds submitted to PEG treatment (-1.48 MPa/120h) without ABA and PEG (-1.48 MPa) with 10ˉ3 or 10ˉ4 μM of ABA (90 h), followed by fast drying at 15% moisture content showed reduction of desiccation sensitivity and high germination and vigor when compared to the other treatments.展开更多
Physiological conditioning of seeds has been shown to increase the uniformity of seedlings;thus, it has been useful for propagating native tree species from the Brazilian Cerrado which, otherwise, are difficult to pro...Physiological conditioning of seeds has been shown to increase the uniformity of seedlings;thus, it has been useful for propagating native tree species from the Brazilian Cerrado which, otherwise, are difficult to propagate successfully. The objective of this work was to evaluate the effect of physiological conditioning of Alibertia edulis seeds by soaking for 5 or 10 days in solutions of varying osmotic potential. After conditioning, seeds were dried down to original water content, sown on sheets of germitest paper inside gerbox plastic boxes, and incubated at 25°C. We evaluated the effect of conditioning by studying seed germination and vigor. Seed conditioning by osmotic pretreatment showed positive effects;however, germination and growth of seedlings from seeds conditioned at osmotic potentials of -0.3 to -0.7 MPa were reduced. Osmoconditioning for 10 days at -0.7 MPa resulted in increased percent germination, indicating that the longest imbibition period in the osmotic solution of the lowest osmotic potential (-1.3 MPa) favored the seed germination process. A. edulis seeds did not require conditioning to attain high germination rates;nonetheless, osmotic conditioning reduced average seed-germination time.展开更多
The present work evaluated the conservation of Campomanesia adamantium seeds under different conditions. The fruits used in the study were collected from matrices located in the city of Ponta Porã-MS, Brazil...The present work evaluated the conservation of Campomanesia adamantium seeds under different conditions. The fruits used in the study were collected from matrices located in the city of Ponta Porã-MS, Brazil. After processing, the seeds were slowly dried to different water content levels and subsequently exposed to various environmental conditions: 25°C ± 2°C, 35% relative humidity (laboratory);16°C ± 1°C, 40% relative humidity (cold and dry);8°C ± 1°C, 35% relative humidity (refrigeration);and -18°C ± 1°C, 42% relative humidity (freezing). Each treatment was conducted for 0 (recently processed seeds, with superficial drying of 40 minutes), 30, 60, 90, 120, 150, and 180 days. Seed potential was physiologically evaluated based on radicle protrusion, percentage of normal seedlings, seedling length (primary root, shoot and total), and dry mass of the seedlings. The experimental design was a completely randomized factorial scheme with split-split plots (4 temperatures/environments × 5 water content × 7 storage periods). C. adamantium seeds tolerated a reduction in the water content to 15.3% but did not tolerate the storage period, confirming the recalcitrant behavior of the seeds.展开更多
This study aimed to evaluate the tolerance of Psidium guineense Swartz seeds to air-dry storage and priming. Desiccation tolerance was analyzed for seed moisture content of 15%, 10% and 5%. The longevity of seeds duri...This study aimed to evaluate the tolerance of Psidium guineense Swartz seeds to air-dry storage and priming. Desiccation tolerance was analyzed for seed moisture content of 15%, 10% and 5%. The longevity of seeds during storage was analyzed in seeds with 5% and 10% moisture content maintained in cold and dry chamber (16°C ± 1°C/40% RH), laboratory environment (25°C ± 2°C/60% RH), refrigerator (5°C ± 1°C) and freezer (-18°C ± 1°C) during 90 days, and the priming effect in seeds that were imbibed for 5 or 10 days in polyethylene glycol 6000 at osmotic potentials of -0.3 MPa, -0.5 MPa, -0.7 MPa and -1.3 MPa. The quality of seeds was evaluated after desiccation, storage, and priming by the seeds germination, fresh weight of seedlings, seedlings growth, and germination medium time. The experimental design was completely randomized, with four replications of 25 seeds each one. Although a reduction in seed germination and seedling growth was observed in seeds with 10% and 5% moisture content, drying did not cause complete loss of seed germination and seedling development. Sour guava seeds exhibited an orthodox response to desiccation tolerance and storage. Seed germination and seedling growth were reduced with increased osmotic potential of osmoconditioning. However, conditioning of 10 days increased the seeds germination and optimized the average germination time to 20 days. The seeds of Psidium guineense are able to tolerate desiccation and storage for up to 90 days at a temperature of 5°C ± 1°C and priming for 10 days is a promising technique for propagation of P. guineense.展开更多
文摘The Copaifera langsdorffii Desf. seedlings, popularly known as “copaiba” or diesel tree, present a natural occurrence in the riparian forests of the Brazilian Cerrado, however, not much is known about their capacity to recover from flooding, particularly when the focus is on their establishment and use in programs for the recovery of degraded areas near watercourses and subject to flooding. The objective of this study was to evaluate over time the recovery of the efficiency of the photosynthetic apparatus and the antioxidant activity of C. langsdorffii seedlings flooded during different periods. The pots with the seedlings were placed in a plastic tank and submerged with water, and were removed from the flood condition every 21 days (0, 21, 42, 63 and 84 days), and evaluated every 30 days (0, 30, 60, 90 and 120 days). The seedlings tolerated the flooding for up to 42 days, recovering after suspension of this condition. Seedlings flooded for 63 and 84 days showed lower recovery capacity after flooding, independently of the evaluation period. Under these conditions, lower efficiency of the photosynthetic apparatus, gas exchange, photo assimilate production and seedling quality were observed.
文摘The Campomanesia adamantium is a threatened species from Brazil Savannah which seeds are desiccation-sensitive and do not withstand storage. This study aimed to reduce the sensitivity of Campomanesia adamantium seeds to desiccation using polyethylene glycol (PEG) and abscisic acid (ABA). Initially, seeds were subjected to PEG (0, -1.48, and -2.04 MPa) with or without ABA (100 μM) during 120 h, followed fast drying (silica gel) or slow drying (laboratory environment), at 20%, 15%, and 10% moisture content. In the second experiment, the seeds were PEG treated (-1.48 MPa) which provided the best results in the first experiment;the seeds were then subjected to different incubation times in PEG (30, 60, 90, or 120 h) and ABA (0, 10ˉ3, 10ˉ4, and 10ˉ5 μM), following the seeds were fast dried at 15% moisture content. The slow drying should be avoided, even in seeds previously subjected to osmotic conditioning with or without ABA. Seeds submitted to PEG treatment (-1.48 MPa/120h) without ABA and PEG (-1.48 MPa) with 10ˉ3 or 10ˉ4 μM of ABA (90 h), followed by fast drying at 15% moisture content showed reduction of desiccation sensitivity and high germination and vigor when compared to the other treatments.
文摘Physiological conditioning of seeds has been shown to increase the uniformity of seedlings;thus, it has been useful for propagating native tree species from the Brazilian Cerrado which, otherwise, are difficult to propagate successfully. The objective of this work was to evaluate the effect of physiological conditioning of Alibertia edulis seeds by soaking for 5 or 10 days in solutions of varying osmotic potential. After conditioning, seeds were dried down to original water content, sown on sheets of germitest paper inside gerbox plastic boxes, and incubated at 25°C. We evaluated the effect of conditioning by studying seed germination and vigor. Seed conditioning by osmotic pretreatment showed positive effects;however, germination and growth of seedlings from seeds conditioned at osmotic potentials of -0.3 to -0.7 MPa were reduced. Osmoconditioning for 10 days at -0.7 MPa resulted in increased percent germination, indicating that the longest imbibition period in the osmotic solution of the lowest osmotic potential (-1.3 MPa) favored the seed germination process. A. edulis seeds did not require conditioning to attain high germination rates;nonetheless, osmotic conditioning reduced average seed-germination time.
基金the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior(CAPES),Programa Nacional de Pos-Doutorado(PNPD/CAPES-Projeto 2673/2011).
文摘The present work evaluated the conservation of Campomanesia adamantium seeds under different conditions. The fruits used in the study were collected from matrices located in the city of Ponta Porã-MS, Brazil. After processing, the seeds were slowly dried to different water content levels and subsequently exposed to various environmental conditions: 25°C ± 2°C, 35% relative humidity (laboratory);16°C ± 1°C, 40% relative humidity (cold and dry);8°C ± 1°C, 35% relative humidity (refrigeration);and -18°C ± 1°C, 42% relative humidity (freezing). Each treatment was conducted for 0 (recently processed seeds, with superficial drying of 40 minutes), 30, 60, 90, 120, 150, and 180 days. Seed potential was physiologically evaluated based on radicle protrusion, percentage of normal seedlings, seedling length (primary root, shoot and total), and dry mass of the seedlings. The experimental design was a completely randomized factorial scheme with split-split plots (4 temperatures/environments × 5 water content × 7 storage periods). C. adamantium seeds tolerated a reduction in the water content to 15.3% but did not tolerate the storage period, confirming the recalcitrant behavior of the seeds.
基金the Coordenaca de Aperfeicoamento de Pessoal de Nivel Superior(CAPES),Programa Nacional de Pos-Doutorado(PNPD/CAPES—Projeto 2673/2011).
文摘This study aimed to evaluate the tolerance of Psidium guineense Swartz seeds to air-dry storage and priming. Desiccation tolerance was analyzed for seed moisture content of 15%, 10% and 5%. The longevity of seeds during storage was analyzed in seeds with 5% and 10% moisture content maintained in cold and dry chamber (16°C ± 1°C/40% RH), laboratory environment (25°C ± 2°C/60% RH), refrigerator (5°C ± 1°C) and freezer (-18°C ± 1°C) during 90 days, and the priming effect in seeds that were imbibed for 5 or 10 days in polyethylene glycol 6000 at osmotic potentials of -0.3 MPa, -0.5 MPa, -0.7 MPa and -1.3 MPa. The quality of seeds was evaluated after desiccation, storage, and priming by the seeds germination, fresh weight of seedlings, seedlings growth, and germination medium time. The experimental design was completely randomized, with four replications of 25 seeds each one. Although a reduction in seed germination and seedling growth was observed in seeds with 10% and 5% moisture content, drying did not cause complete loss of seed germination and seedling development. Sour guava seeds exhibited an orthodox response to desiccation tolerance and storage. Seed germination and seedling growth were reduced with increased osmotic potential of osmoconditioning. However, conditioning of 10 days increased the seeds germination and optimized the average germination time to 20 days. The seeds of Psidium guineense are able to tolerate desiccation and storage for up to 90 days at a temperature of 5°C ± 1°C and priming for 10 days is a promising technique for propagation of P. guineense.
