No abstract

2 Chlorophyll meter (SPAD) readings can play an important role in selecting promising lines for wheat breeding. Twenty five durum wheat (Triticum turgidum L. var. durum) genotypes were grown under irrigated and rainfed conditions at two locations in Diyarbakir, Turkey during 2005 and2006. The aim of this study was to evaluate the genetic variation in SPAD readings, and to determine relationships among SPAD readings, grain yield, grain quality and yield parameters. SPAD readings were taken at heading and grain middle milky stages. SPAD readings exhibited greater genotypic variance compared with grain yield and protein content. Genotype by environment interaction variance did not associate with SPAD readings and, grain yield. At both measuring stages there were positive correlations between SPAD and grain yield. Correlation analysis revealed that grain yield under both rainfed and irrigated conditions was mostly determined by grain number. These results suggest that SPAD readings can be used as selection criteria to select durum wheat genotypes that are high yielding but without any decrease in grain protein content.