Tolerance of rice germplasm to salinity and other soil chemical stresses in tidal wetlands uri icon

abstract

  • The results of screening trials conducted over the past 25 years for tolerance of rice to tidal wetland conditions have been incorporated in a Problem Soils Germplasm Database. The database is used to assess the extent of salinity tolerance in the rice germplasm and relationships between tolerances to salinity and other soil chemical stresses common in tidal wetlands: alkalinity, P deficiency, Zn deficiency, Fe toxicity and peat soils. Tolerances to salinity and alkalinity were positively associated, saline-tolerant germplasm often being tolerant of alkalinity and vice versa. Tolerances to salinity and Zn deficiency were also positively associated. However, tolerances to salinity and P deficiency were negatively associated for scores from greenhouse screening in which only the internal P efficiency of the plants was assessed, and not associated for scores from field screening. Tolerance for salinity and Fe toxicity was negatively associated. Salinity and peat soils were positively associated, probably because of tolerance to Zn deficiency, which is common to both. It is concluded that multiple tolerance for some combinations of stresses exists. But unless selected in breeding programs, tolerances may be lost over time. To preserve tolerance to combinations of stresses, ready means of identifying tolerances to the individual stresses are required. (C) 2002 Elsevier Science B.V. All rights reserved.

publication date

  • 2002
  • 2002