n.a. bagheri

Identification of suitable restorer lines is one of the main priorities of hybrid rice production technology, followed by the production of local male sterile lines. To study fertility genetic capacity of 14 landraces, improved and foreign rice varieties, a test cross scheme was conducted using Neda-A male sterile line as female parent for the production of F1s in 2018 at Genetic and Agricultural Biotechnology Institute of Tabarestan, Sari Agricultural and Natural Recourses Sciences University, Sari, Iran. At the flowering stage, the sterility and fertility of pollen grains were tested using IKI solution. At the physiological maturity stage of F1s agronomic traits such as days to 50% flowering, days to physiological maturity, plant height, number of fertile tillers, panicle length, number of grain per panicle, grain length, grain width, 100 grain weight, grain length: width ratio, panicle fertility percentage and grain yield were measured and recorded. The results of pollen grain and panicle tests of hybrids showed that the hybrid derived from Shiroodi × Neda-A hybrid had 100% sterility indicating that this variety is a maintainer, in other words, it carries normal cytoplasm and rf-induced nuclear gene. Given the larger cultivated areas of cv. Shiroodi and its earlier maturity than Neda variety, it is concluded that cv. Shiroodi would be more suitable for hybrid rice seed production. Therefore, Shiroodi-A line can be developed through backcrossing. The highest grain number per panicle (217 grain) was obtained from hybrid CB06-550. The highest 100 grain weight belonged to the hybrid Jahesh × Neda-A which is due to its larger grain size. By evaluating pollen and panicle test, Binam, Pardis and PR37181-1-1-2-1-2-1 varieties were identified as poor fertility restorer lines. IR50 and IR67924R lines with more than 96 and 80% fertility, respectively, were identified as strong fertility restorer lines. These sterile lines can be used to produce hybrid rice with higher yield than varieties developed through conventional breeding methods. Other lines developed in this study can be used in the development of hybrid technology in the rice heterotic gene pool.