| Popis: |
Salinity is the main constrain to rice production in Egypt. The high heterosis displayed by hybrid rice might be exploited for the enhancement of rice productivity in the presence of economically-important stresses such as drought and salinity. Three field experiments were conducted during summer seasons of 2010, 2011 and 2012 rice seasons at El- Sirw Agricultural Research Station as saline soil and EL- Gemmiza Agricultural Research Station as normal soil. The salinity levels were 8.2, 8.5 and 8.3 dsm-1 in ,2010, 2011 and 2012 seasons, respectively as saline soil and 1.9 and 1.8 dsm-1 for normal soil. In 2012 season, the best selected genotypes compared with the salt tolerant variety Giza 178 were physiologically evaluated under saline soil. Fifteen rice genotypes, nine hybrids, SK2034H, SK2046H, SK2035H, SK2058H, SK2074H,SK2010H, SK2121H, SK2122H, SK2037H, and six inbreeds rice, Giza 177 (salt sensitive), Giza 178 ( the best salt Egyptian variety), Giza 182 (Sensitive one), Sakha 101 (moderate salt tolerant one), Sakha 102 ( Sensitive one) and Sakha 104 ( moderate salt one) were used in this investigation . Studied genotypes significantly varied in all studied parameters under both saline and normal soils. Under normal soil all tested hybrids significantly surpassed the studied inbreeds but hybrid 8 was less all of inbreeds except Giza 177 and Sakha 102. While, under saline soil conditions, there are only three hybrids; SK2034H, SK2035H and SK2058H markedly exceeded the salt tolerant inbred rice variety Giza178 in large score. The hybrid SK2046H gave the highest number of panicle hill-1 under normal condition, while, SK2058H gave the highest values of panicle number under saline soil for this trait.The ability of SK2034H, SK2055H, SK2058H, Hybrids and Giza 178 to keep high filled grains under saline soil The results obtained indicated that the three hybrids SK2034H, SK2035H and SK2058H could be recommended to be grown under saline soil with yield increase of 16–22 % over Giza178 as inbred salt tolerant one that may be due to their high heterosis. On the other hand, SK2058H markedly surpassed the other two hybrids. It could be concluded that SK2058H gave the highest means in all seedling characteristics, number of white roots, root dry weight of seedling, shoot dry weight, root length, shoot length and number of leaves plant-1 under saline soil during the last seasons without significant differences compared with those produced by hybrid SK2034H. On the other hand, the lowest values of aforementioned traits were recorded by Giza 178 inbred salt tolerant variety. |
