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PHYSIOLOGIC AND SANITARY QUALITY OF Senna macranthera (DC. ex Collad.) H.S.Irwin & Barneby WHEN SUBJECTED TO METHODS TO OVERCOME DORMANCY

ABSTRACT

Senna macranthera, better known as manduirana, belongs to the family of Caesalpiniaceae and occurs naturally in the region from the states of Paraná to Rio Grande do Norte. It is a pioneer species, characteristic of secondary education. The objective of this study to determine the health and physiological quality of Senna macranthera seeds when subjected to methods of overcoming dormancy. The seeds were submitted to break dormancy by: acid scarification for 10, 15, 20 and 25 minutes; immersion in hot water with temperature of 70, 80 and 90 °C by cooling for 24 hours; immersion in gibberellic acid (GA3) at a concentration of 250 and 500 mg.L-1, 24 and 48 hours; immersion in potassium nitrate (KNO3) at a concentration of 0,2% for 24 and 48 hours. Then they were made the health tests, germination and tetrazolium. The experimental design was completely randomized with four replications of 25 seeds per treatment. The comparison of means between the different treatments to overcome seed dormancy was conducted by the Tukey test at level 5% significance. The main genera of fungi found associated with the seeds were Penicillium sp. and Aspergillus sp. The Senna macranthera seeds had higher germination rate when subjected to acid scarification for 15 and 20 minutes, hot water at 70°C; soaking in GA3 250 mg.L-1 for 48 hours and KNO3 for 48 hours. The use of rapid tests, such as the tetrazolium test, proved inefficient, since there was an overestimation of seed vigor.

Keywords:
manduirana; germination; tetrazolium test; fungi

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