Tolerance of rice germplasm to zinc deficiency

A database is described containing the results of screening trials for tolerance to zinc (Zn) deficiency and other soil stresses made by IRRI and collaborators over the past 25 years. The data are scores based on visual symptoms in field and greenhouse screenings and yield data from field trials. The database: includes search and retrieval functions. It can be downloaded from ftp://ftp.cgiar.org/icis. The data are used to explore differences in tolerance and relations with other plant and environmental variables. It is concluded that there is useful variation in tolerance to Zn deficiency in the rice germplasm that could be exploited in breeding programs. There appears to be no yield cost associated with tolerance, and tolerant genotypes often also have tolerance to salinity and P deficiency for reasons that are not apparent. Tolerance can be identified satisfactorily by scoring for visual symptoms in early growth stages in well-managed Zn-deficient soils. This simple procedure lends itself to large-scale screening, for example of populations for gene mapping. (C) 2002 Elsevier Science B.V All rights reserved.