Hybrid rice parental lines with better combining abilities provide an efficient tool to increase rice production. In the current study, twenty hybrid combinations were generated from five aromatic cytoplasmic male sterile (CMS) lines and four restorer lines (three of them aromatic) using a line × tester mating design. The hybrids and their parental lines were evaluated under two water regimes: normal irrigation and water-stress. Ten yield-component traits were studied over a period of 2 years, and the significant differences between the parents and hybrids are reported in this investigation. Overall, all yield component traits were significantly affected by the water deficit and were governed by both additive and non-additive gene actions. More specifically, the grain yield (GY) was mainly controlled by non-additive gene action under both normal and water-stress conditions. The contribution of the additive variance (σ2 A) was more prominent in the genetic components of traits as compared to the dominance variance (σ2 D). The aromatic parental line CMS IR58025A and the restorer line PR2 were recorded as the best combiners for the GY and good combiners for many other characteristics under both growth conditions. The cross combinations Pusa12A/IR25571-31R and Pusa12A/Giza-Basmati-201 revealed significantly positive specific combining ability (SCA) effects for the GY under both normal and water-stress conditions. The inconsistent correlation between the general combining ability (GCA) and SCA manifested complex interactions among the positive and negative alleles of the genes controlling the yield traits. Generally, the findings of this investigation demonstrated the importance of the GCA and SCA for understanding the genetic components and gene actions of the yield characteristics in new aromatic hybrid rice parental lines. Therefore, we recommend considering these findings in the selection of elite parents for developing superior aromatic hybrid rice varieties under water-stress conditions.

Combining ability and genetic parameters analysis for agronomic, yield and its component characters were carried out in rice through line x tester analysis of 20 hybrid rice combinations developed by crossing four Photo-Thermosensitive Genic Male Sterility (PTGMS) lines (females) with five male lines / varieties along with parents and check. The 20 hybrids with nine parents were grown in a randomized complete block design with three replications. The experiments were conducted at RRTC in 2010 and 2011growing seasons. Data analysis of variance for combining ability revealed a significant differences among PTGMS lines for plant height, panicle length, panicle weight and filled grains panicle-1 , indicating the importance of additive genetic variance in the inheritance of these characters. The mean squares due to female PTGMS lines were found non-significant for days to heading, tillers plant-1 , spikelet fertility%, 100-grain weight and grain yield characters, indicating the prevalence of non-additive genetic variance and suggesting the importance of heterosis breeding for improvement of rice. An overall appraised of GCA effects revealed that among females; PTGMS-80 and PTGMS-51 had a good general combiners for most characters. Among PTGMS and the tester lines, PTGMS-80 and the tester line JRL-252 had favorable genes for grain yield and the most of desirable characters under study. The hybrid combinations PTGMS-80 x JRL-252 followed by PTGMS-51 x Giza 177 were the best specific hybrid combinations which have significant values for grain yield with desirable characters.

Photoperiod and thermosensitive genetic male sterile (PTGMS) lines have become one of the main sources of global rice production increasing. This study was conducted to evaluate the fertility alteration and validate the male sterility genes using validation markers in novel Egyptian Indica and Japonica PTGMS lines under natural conditions. The study revealed that the new genetic male sterile lines belong to the type of photo–thermosensitive genetic male sterility (PTGMS). The fertility alteration of these lines has influenced by photoperiod and temperature interaction. The new PTGMS lines have three sensitive periods of fertility alteration; transformation, sterility, and fertility period. Furthermore, the sensitive stage of fertility transformation might be from secondary branch primordial to pollen mother cells (PMC) meiosis. Under the natural Sakha condition, the new PTGMS lines were stable sterile under the condition of day length upper 13,75 h and temperature over 25 °C, while its convert to fertile under day length under 13 h, and temperature lower than 24 °C. The co-dominant markers identified the pms3 and tms5 genes in the new PTGMS lines, indicated that the fertility alteration in these lines controlled by photoperiod and thermosensitive stages.

This study was conducted to determine the impact of sun light, UV and magnetized water on Dura Sorghum sp. variety plants the Sudanese main stable food. The morphological changes of the Sorghum plants in terms of plant height, color of leaves, growth and development was monitored. The impact of light stress on plants was done by isolating he plant from light for a period of time. The result showed that light stress resulted in retarding growth, yellowing of the leaves and finally plant death after a very short period time. Second the impact of UV on plants along different periods of time showed negatively effect. The effect of magnetized water on the plant indicated that magnetized water has a positive effect on Dura plant growth and development. Though light stress has a significantly negative impact on plant growth and could lead to its death.

Studies of heterosis and combining ability of six photo /thermo-sensitive testers were estimated using line x tester analysis for some agronomic characters and yield and its components to get useful information for two-line system in hybrid rice breeding in Egypt .The outstanding hybrid combinations for grain yield plant -1 were PTGMS-5/Dular (45.26%) with significant standard heterosis for ,panicle length (28.22%) productive tillers plant -1 (24.19%) ,panicle weight (26.93%) ,filled grains panicle -1 (25.89%),spikelets panicle -1 (14.19%) ,spikelet fertility % (10.20% ) and 100-grain weight (35.62% ) .In the mean time ,PTGMS-14/Norin PL9,PTGM-7/Dular ,PTGMS-14/Giza178 and PTGMS-5/Giza 178 were considered as promising hybrids.Among the six PTGMS lines,PTGMS-5 and PTGMS-14 were the best general combiners for grain yield and all studies characters.The testers , Dular , Giza178,M202 and Pecos were the best general combiners among testers for grain yield and most studies characters.