Rapid Screening for Salt Tolerance In Specialty Peppers

Chile peppers are economically important crops in southern regions in the United States. Limited information is available on irrigation management with low quality water or with salt-affected soils. Although previous studies indicate that peppers are moderately sensitive to salt stress, some cultivars may express more tolerance than others. The threshold of salinity that initiates growth suppression varies with species and other environmental factors. The objective of this study was to rapidly screen the relative salt tolerance of a large number of cultivars and breeding lines. Seeds of selected peppers were germinated and seedlings grown in 1.8 L pots. When plants reached 4 to 6 true leaves, salinity treatments were initiated by irrigating with nutrient solutions (control) or saline solutions at electrical conductivity of 3.0 dS/m for the first week and 6.0 dS/m thereafter. Leaf conductance was measured several times during the course of the experiment. After one month of treatment, shoots were harvested and dry weights were recorded. In experiment 1, 13 cultivars or breeding lines were tested. Among them, ‘Early Jalapeño’, ‘AZ-20’, ‘Joe Parker’, and ‘Sandia’ had smaller reductions in shoot dry weight. In Experiment 2, among the seven cultivars or breeding lines, ‘TAM Hab 1’, ‘TAM Jal 1’, and ‘Jupiter’ had smaller growth reductions. Further studies will be conducted to confirm the relative salt tolerance of these cultivars.