Graphical abstract

Commercial exploitation of hybrid vigor is one of the most important applications of genetics in agriculture. It has not only contributed to food security, but has also benefited the environment, the hybrid rice Produced by crossing between two parents and the productivity increased by 20-30% than the inbred high yielding variety. The systematic of hybrid rice included three line system, two line system and One line system. The PCR technique can be used as one of the indicator for predicting the genetic purity of CMS lines, based on polymorphism among parental lines, this characteristic has been used in China to perform preliminary evaluation of the purity of hybrid rice seeds. Hybrid rice research was initiated in Egypt in 1982, to determine natural fertility restoration of Egyptian varieties on some Chinese CMS lines, evaluate certain CMS lines, test productivity of some hybrid varieties and to estimate yield and determination of seed setting percentage of some CMS lines under Egyptian conditions, but, the first Egyptian hybrid was released during 2004. For the two line system, discovery and successful utilization of environmental genic male sterility (EGMS) led to development new promising hybrids of the two lines system in hybrid rice breeding program, compared with the three-line system. EGMS trait is governed by major genes could be transferred to any genetic background and no need to use restorer genes in the male parents of two line hybrids. Finally, this system is ideal for developing indica / japonica hybrids because most japonica lines do not possess restorer genes. Molecular studies is concerning on selecting populations which can be used as the new reverse-thermo sensitive genic male sterile (rTGMS) lines to produce Japonica hybrids under Egyptian condition by using one specific SSR primer RM222.

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seasons, selection was performed in M2, M3, M4, M5 and M6 generation. Sixteen homogeneous and stabile lines were grown during 2013 season under different conditions in three locations (Sakha, Gemmiza as normal soil and EL-Sirw as saline soil stations). The experimental design was a split plot design with four replications. The main plots were devoted to irrigation intervals, while, sub plots were devoted to induced mutants under different conditions in three stations. During 2014 and 2015 seasons, all the induced mutants were evaluated in RCB design with four replications under conditions of Sakha Agric. Res. Station. Data were recorded on days to maturity (day), 1000-grain weight, grain yield (t/ha) and yield reduction %. Data were recorded on days to maturity (day), 1000-grain weight, grain yield (t/ha) and yield reduction %. The desirable values of early maturity, grain yield (t/ha) and grain yield reduction were recorded for Giza 178 M8-4, Sakha 104 M8-4,101 M8-4, and Giza 177 M8-4under different irrigation intervals 3, 6 and 9 days in different research stations (Sakha, Gemmiza and El-Sirw) during 2013 season. Also, these mutants of Sixteen Entries were differed in Sakha Research Station during 2014 and 2015 seasons, whereas, Giza 178M8-4, Sakha 104 M8-4, Sakha 101 M8-4 and Giza 177 M8-4 recorded the desirable values for days to maturity and highest values for 1000 grain weight and grain yield, Sakha 101 M8-4, Giza 177 M8-4, Giza 178M8-4 and Sakha 104 M8-4 could be used as new promising lines tolerant to stress conditions better than their parents.