Catalase deficiency reduces survival and pleiotropically affects agronomicperformance in field-grown barley progeny

Field-grown plants of the catalase-deficient mutant RPr79/4 show necrotic l esions in leaves and preferentially die. Initially, necrotic lesions exhibi ted by RPr79/4 were used to indirectly assess the role of distinct levels o f catalase on the survival and agronomic performance of field-grown barley progeny. The segregation of three control traits was also analyzed to elimi nate the influence of any obvious meiotic disturbance in case a reduction o f plant survival was observed. The RPr79/4 necrotic phenotype had recessive expression in field-grown Fl plants. F2 progeny studies performed in the g reenhouse revealed that the inheritance of necrotic lesions was monofactori al, and that the control traits segregated as expected. Progeny rest analys es of field-grown F2 plants demonstrated that necrotic homozygous plants di ed preferentially. While the few surviving necrotic homozygous families wer e catalase-deficient, healthy homozygous families had normal levels of cata lase. Progeny test analyses of the control trails confirmed the inheritance calculated in F2. Taken together, these findings indicate that abnormal se gregation of necrotic lesions cannot be attributed to any obvious abnormal meiotic behavior but to the incapacity of catalase-deficient plants to over come field stress conditions. Thus, catalase deficiency in barley reduced s urvival and pleiotropically affected the agronomic performance by diminishi ng seed weight and yield. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.