GENETICAL AND MOLECULAR STUDIES ON SALINITY AND DROUGHT TOLERANCE IN RICE (ORYZA SATIVA L.)

Document Type : Original Article

Abstract

The field experiments were conducted during 2013 and 2014 growingseasons at Kafrelsheikh University and Rice Research and Training Center(RRTC), Sakha, Kafrelsheikh, Egypt, facilities at El-Sirw Agriculture ResearchStation experimental farm, Damietta governorate, Egypt. Eight-parental halfdiallel cross and eight SSR molecular markers were used to determinecombining ability of some common rice genotypes grown under normal,drought and salinity conditions. Analyses of variance were highly significantfor days to heading, plant height, total chlorophyll content, proline content,sodium content, potassium content, Na+/K+ ratio and panicles plant-1, filledgrains panicle
 -1 and grain yield plant-1 indicated highly significant differencesamong the studied genotypes for this traits. The estimates of GCA effectsindicated that three rice genotypes i.e. Giza178, A22 and WAB56-125 werethe best general combiners for total chlorophyll content, proline content,sodium content, potassium content, Na+/K+ ratio, panicles plant-1, filled grainspanicle
 -1 and grain yield plant-1 under normal, salinity and drought conditions.The estimates of SCA effects indicated that the most desirable hybrids wereSakha105 x A22, Sakha102 x A22 and Sakha104 x Giza178 for totalchlorophyll content, panicles plant 
-1 and grain yield plant-1; Giza178 x WAB56-125 for filled grains panicle
 -1; Sakha102 x Sakha104 for days to heading;Sakha104 x Sakha105 for plant height. The genetic distance, measured usingSSR markers, differed from 0.00 to 0.79 among the eight genotypes.Microsatellite markers were effective in predicting the mean and the varianceof SCA in various cultivar combinations. In addition, RM223 marker elucidated
the possibility to use it in MAS for salinity and drought tolerance in the studiedrice genotypes according to different alleles.