Differential response of three Phaseolus vulgaris L. cultivars to in vitro water stress induced by PEG-6000

Abstract

The growth and agricultural yield of common beans (Phaseolus vulgaris L.) is affected, among other factors, by limitations in the availability of water. For this reason, there are working on the search for cultivars tolerant to that abiotic stress. The objective of the research was to determine the effect of different concentrations of PEG-6000 on the in vitro seeds germination of three cultivars of common bean (ʹIca Pijaoʹ, ʹBAT-93ʹ and ʹTío Canela-75ʹ) with different responses to water stress. PEG-6000 was used as an in vitro stress-inducing agent at 10, 12 and 14% (m / v) in the liquid culture medium. Deionized water was used as a control. Seeds of each cultivar were placed on a filter paper located in the shape of an M inside the test tube containing the corresponding solution. After three days of culture, the number of germinated seeds was quantified and the percentage of germination was calculated. Subsequently, at seven days the length of the root, hypocotyl and epicotyl, respectively, was measured. In the three cultivars, water stress affected the in vitro germination of the seeds in each of the treatments. There was a significant decrease in the values of the variables evaluated with respect to the control. Specifically, the growth of epicotyl was inhibited. The response to water stress in vitro induced with PEG 600 in each cultivar was specific and differential. The results contribute to the development of early selection strategies in the genetic improvement program of this crop.

Keywords

• abiotic stress
• common bean
• epicotyl
• germination
• hypocotyl
• root