Germinação e vigor de 10 genótipos de arroz (Oryza sativa L.) submetidos a 5 níveis de NaC1 e água salina de açude.

Abstract

With the objective of studying the effect of two types of salts (saline water of dam and NaCl) and five salinity levels (0,0; 2,5; 5,0; 7,5 and 10,0 dS.m-1) in the germination and vigor of 10 genotipos of rice (Oryza sativa L.), she behaved an experiment, in conditions controlled in the Laboratory of Processing and Storage of Agricultural Products of UFPB, Campina Grande, Paraiba, in the period of March to December of 1998. For the experiment it was used as substratum paper Germitest, in a delineamento entirely casualizado in outline fatorial 1 0 x 2 x 5 , with four repetitions, each one contends 50 seeds for the standard test of germination (TPG), which was accomplished with readings done at the 5, 10, 15 and 20 days after the semeadura, the emergency speed was analyzed (VE), index of emergency speed (IVE) and I weigh of the dry matter of the plantulas. There was influence of the salinity on the germination and the vigor of the plantulas. The genotipos of rice showed behavior differentiated in relation to the acting germinativo for the different established salinity levels for the saline water of dam and NaCl. The increase of the salinity produced a decrescimo of the germination, index of emergency speed (IVE) and I weigh of the dry matter of the plantulas. For all the genotipos under the effect of the salinity, the best acting germinativo is obtained at the level of 2,5 dS.m-1. THE effect of the salinity on the germination and the vigor of the plantulas, was severe starting from 5,0 dS.m-1. The genotipos PR-349, CNA-7979, Beautiful Rio and CT-8452 didn't germinate (0,0%) when submitted the electric conductivity of 2,5 dS.m-1, promoted by NaCl. The genotipos CT-8452, Beautiful Rio, PR-306 and PR-349 were the ones that they presented larger viability in the standard test of germination (TPG) when submitted to the saline stress simulated by NaCl and saline water of dam. In the relative reduction for the saline water of dam the worst acting was revealed by the genotipos Diamond, Metica 1, CNA-7979, CT- 8452 and CNA-7222 and for NaCl the genotipos CNA-7979, Beautiful Rio and CT-8452. The medium time requested for a satisfactory evaluation of the germination in a little saline, in comparison to the established by the Rules for Analysis of Seeds (RAS) it is more of 10 days the in relation to first contagem and 6 days for the second reading. Among the used tests IVE and VE they can be prescribed as the most efficient to evaluate the vigor of the seeds of rice in a little saline of 2,5 dS.m-1 and 5,0 dS.m-1 and the dry matter of plantulas when the stress is promoted by NaCl.