Nitrate levels and stages of growth in hypernodulating mutants pf Lupinus Albus. I. N2 fixation potential
Rev. microbiol
; 30(2): 91-7, abr.-jun. 1999. tab
Article
em Pt, En
| LILACS
| ID: lil-257201
Biblioteca responsável:
BR32.1
ABSTRACT
This work aimed to evaluate physiological parameters, nodulation response and N2 fixation rate in mutants of Lupinus albus in comparison with the standard Multolupa cultivar. Two nitrate levels (0 and 5mM) and two evaluation periods (7 and 10 weeks) were used. Significant differences were observed among genotypes, in relation to fresh nodule weight, nitrate levels and growth stages. The overall average for nitrate level differed between them where 5mM severely inhibieted the number of nodules, reaching a 49.5 (per cent) reduction in relation to treatment without nitrate. There were no behaviour differences among genotypes, nor among evaluation periods. Although the level of nitrate did not influence the production of shoot dry matter in relation to the average among levels applied, the L-135 genotype, being an inefficient mutant, reached very low values. There were no significant differences in electron allocation coefficient (EAC) among nitrate levels, nor among genotypes studied. However , the evaluation periods revealed differences, where the EAC for the seventh week had a higher value than that for the tenth week, when a 5mM aplication was evaluated. The N2 fixation rate (N2FIX) showed the existence of the nitrate interference in fixation, given that the application of 5mM severely reduced. However, there were no differences among the genotypes and it was noted that the fixation rate was much higher in those that received nitrate. The L-88 and L-62 genotypes were the ones that have shown best adaptability in this experiment, thus being able to be recommended for new studies with higher nitrate levels and different evaluation periods. The nitrate (5mM) interferes in the nitrogen fixation rate, given that all the genotypes were affected by the level applied.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Fabaceae
/
Nitratos
/
Fixação de Nitrogênio
Idioma:
En
/
Pt
Revista:
Rev. microbiol
/
Revista de microbiologia
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil