In order to develop a high yielding rice cultivar with optimum cooking quality, a cross was conducted between two rice cultivars Khazar, high yielding and resistant to blast disease and Daylamani Tarom, with good cooking quality in 1990. Forty pure lines were selected and compared for high grain yield in 1996. Ten selected lines together with two check cultivars Dasht and Onda were tested in advanced yield trails in Amol, Chalous and Tonekabon for three years. Overall, mean yield comparison suggested that line No. 5 produced the highest yield (6.5 to 7 tha-1) and showed a good stability over the years and locations. Based on the results on agronomic trails, row spacing of 10×30cm, 110 kg pure nitrogen and planting date of 25 May can be recommended for the new line. The new line is resistant to rice blast, tolerant to stem borer and moderately susceptible to sheath blight disease. This line, has some important characteristic such as moderate amylose content (23.5%), suitable plant height (106 cm), long panicle length (27cm), high weight of 1000 grains (26g), early maturity (124 days) and high yield (6.5-7t/ha). The new line was officially registered as a new rice cultivar in Iran with the name of Shiroudi in 2007.
)
