To study pre-harvest sprouting resistance, 30 bread wheat cultivars were planted in a randomized complete block design (RCBD) with three replications at the Research Farm of University of Tehran in Karaj in 2000. Days to 50% heading, days to 50% anthesis and Zadoks Growth Stage 92 (ZGS92) were recorded. Spikes were harvested at ZGS92, and grain moisture content measured for all cultivars. Cultivars were evaluated for sprouting resistance by two screening methods, namely, sprouting score and sprouting index. Likewise, seed dormancy, length of after-ripening and falling number were studied under laboratory conditions. Significant genetic variations were detected for all measurements among cultivars. The results of screening methods indicated that most Iranian bread cultivars have low resistance to pre-harvest sprouting. Correlation analysis revealed negative significant correlation between pre-harvest sprouting, seed dormancy and falling number. Also there was a positive significant correlation observed between seed dormancy and falling number. The study of correlation indicated that after-ripening was in most correlation with sprouting score as well as with sprouting index. Cluster analysis indicated that there existed a favorable diversity among cultivars.
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