Evaluation of common bean advanced lines to the water deficit during seedling stage

Abstract

The common bean (Phaseolus vulgaris L.) is the most  important  food  legume  in  Latin  America but it is often sowed to unfavorable conditions. The objective of this research was to evaluate advanced lines of common bean to drought stress during the seedling phase. The seeds of nineteen common bean lines were placed to germinate on filter paper moistened, subjected to water stress with different concentrations of polyethylene glycol (PEG) and located in a dark chamber at 25ºC, under laboratory conditions. Four proportions of 0 (control) were used; 10; 15 and 20% of PEG 8000 diluted in a Hoagland solution. Fifteen days after sowing were evaluated the germination, the presence  of  hypocotyls,  epicotyls,  true  leaves, and length of root, stem, and number of lateral roots. Common bean advanced lines showed a differential response to PEG 8000 concentrations in the seedling stage. With the increase of the concentrations of PEG 8000 there was an increase in the percentage of inhibition of the germination and a decrease in the length, fresh weight of the stem and root. The % inhibition of the germination of lines 1, 3, 4, 5, 7, 9, 10 and 15 was less affected by the higher concentration of PEG 8000. The % inhibition of lines 8, 12, 13 was not affected to 10 and 15% of PEG 8000, the latter being considered as moderately tolerant and the former as tolerant to water deficit.