Roshan and Shahryar, two new mutant cultivars of rice (Oryza sativa L.) with distinguished agronomic and grain biochemical properties

Although plant breeding has been able to increase rice yield, the quality of cooking and eating quality is still one of the most important economic factors in rice production. In order to better understand the genetic relationships between quantitative and qualitative properties, the most important agronomic traits, physicochemical properties and storage protein characteristics in two new mutant cultivars of rice, their parents and ancestors were evaluated. The results of agronomic traits showed that two mutant cultivars Roshan and Shahriar, have the highest yield (8500 and 8000 kg/ha respectively) accompanied by desirable agronomic characteristics such as lodging resistance, early maturity period, high number of tillers and more panicle length. Evaluation of qualitative properties also showed that these two new mutant cultivars characterized by good cooking and eating properties. As Roshan, show moderate amylose content (AC) and both of them were in terms of gelatinization temperature (GT) and gel consistency (GC) similar to Sangetarom, a quality cultivar. Also, Roshan cultivar, like Sangetarom, was differentiated by the recessive allele of BADH2 gene for fragrance. On the other hand, Shahriar cultivar also showed a significant decrease for prolamin protein. In general, the results show that there is no significant relationship between agronomic characteristics and yield with grain biochemical properties, such as cooking and eating quality, fragrance and storage protein content. These results promise that by identifying and pyramiding desirable alleles, especially alleles involved in starch synthesis, fragrance and prolamin protein can be obtained rice cultivars with higher qualitative properties.