African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12365

Full Length Research Paper

Differential responses of Chiltepin (Capsicum annuum var. glabriusculum) and Poblano (Capsicum annuum var. annuum) hot peppers to salinity at the plantlet stage

Raúl López-Aguilar, Diana Medina-Hernández, Felipe Ascencio-Valle, EnriqueTroyo-Dieguez, Alejandra Nieto-Garibay, Mario Arce-Montoya, Juan A. Larrinaga-Mayoral and Gracia A. Gómez-Anduro*    
Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Mar Bermejo 195, Col. Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico.    
Email: [email protected]

  •  Accepted: 31 October 2011
  •  Published: 07 February 2012

Abstract

Poblano (Capsicum annuum var. annuum) and Chiltepin pepper (Capsicum annuumvar. glabriusculum) are considered closely related parent species. Poblano pepper is a cultivated species that has lost stress tolerance attributes, and Chiltepin is a wild species adapted to adverse environmental conditions, such as salinity stress. Differential physiological responses between the wild and cultivated species were compared in order to study the physiological and biochemical mechanisms of Chiltepin’s salinity tolerance. Salt stress treatments were applied to Chiltepin and Poblano and their growth, chlorophyll content, transpiration rate, and concentrations of anions and cations in leaves, stem and roots were measured. Dry weight and relative growth index decreased significantly with salt stress in Poblano, chlorophyll-a decreased significantly in both peppers and transpiration decreased in Chiltepin, with no significant changes evidenced by Poblano. Concentrations of Na+ and Clincreased in stems and roots, but K+ declined in stems for both peppers, evidencing changes proportionally associated to the salt treatments. The accumulation of Na+increased and the ratios K+/Na+, Ca2+/Na+, and Mg2+/Na+ decreased at all concentrations of NaCl. Sulfate, nitrate and phosphorus did not show significant differences in both species. We confirm that Chiltepin possessed salinity tolerance and also was physiologically more tolerant to salinity than Poblano.

 

Key words: Salt stress, Capsicum, physiological traits, ion uptake, peppers.