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PHYSIOLOGY OF SEED GERMINATION OF Dalbergia nigra(Vell.) Allemão ex Benth. UNDER DIFFERENT TEMPERATURES AND EXPOSURE TIMES

The seeds germination depends on abiotic factors, the temperature being one of the most important, whose influence, in extreme conditions, causes damage to the seeds. The present study aimed to investigate the effect of different temperatures during germination of Dalbergia nigra and its implications in the physiology of the seeds. We evaluated the percentage of germination, germination speed index (GSI) and integrity of cell membranes by electrical conductivity test of seeds at different times of exposure to temperatures of 5, 15, 25 (control), 35 and 45 ºC. The temperature of 25 ºC was the ideal temperature for germination. At temperatures of 5 and 45 ºC germination was null. There was a reduction of germination of D. nigra seeds with the increase of the exposure time of the seeds at temperatures of 5, 15, 35 and 45 ºC. Unlike other temperatures, the semipermeability of the membrane is not recovered at temperatures from 5 to 45 ºC. Electrical conductivity is an efficient technique to evaluate the physiological quality of the seeds at different temperatures.

Physiology; Jacarandá-da-bahia; Cell membranes


Sociedade de Investigações Florestais Universidade Federal de Viçosa, CEP: 36570-900 - Viçosa - Minas Gerais - Brazil, Tel: (55 31) 3612-3959 - Viçosa - MG - Brazil
E-mail: rarvore@sif.org.br