Growth, yield, genetic parameters and random amplified polymorphic DNA (RAPD) of five rice varieties treated with sodium azide and sown under different saline conditions

Abstract

BackgroundRice is probably one of the most indispensable grain diets for the greater part of the world. It can be grown successfully under a wide range of climatic conditions; however, yields can be significantly diminished under moderate saline levels. Therefore, the employment of plant breeding techniques in enhancing plant survival and performance capacities under saline conditions becomes imperative. Mutation perhaps is one of the ultimate sources from which heritable variations could be selected from and hence are a useful tool to create raw materials for genetic improvement of rice. The effects of sodium azide (NaN3), as a chemical mutagen, on the growth, yield, genetic parameters, and RAPD profile of five rice varieties, FARO-44, FARO-52, FARO-57, NERICA L-34, and NERICA L-47, sown in soils maintained at a conductivity range of 4000 to 6000 μs/cm using sodium chloride solutions were investigated. The planting materials were treated with 0% NaN3 at pH 7 (control) and a concentration range of 0 to 0.032% NaN3 at pH 3 for 6 h.ResultsSodium azide treatment significantly reversed the negative effects associated with plant development under saline conditions. Consequently, NaN3 treatment significantly improved growth, yield, and genetic parameters of the rice varieties under high salinity compared with the controls. High heritability values were recorded for number of tillers per plant (78.06%), number of panicles per plant (78.74%), and 100-grain weight (98.15%) indicating the possibility of evolving higher yield variants through selection. Chlorophyll mutations observed were albino, viridis, and striata. The RAPD analyses with primers OPR 02 (5′–CAC AGC TGC C-3′), OPC 04 (5′-CCG CAT CTA C-3′), and OPC 05 (5′–GAT GAC CGC C-3′) revealed different DNA banding patterns between controls and NaN3-treated plants.ConclusionsThe study indicates that sodium azide is a potent mutagen, evident from information on genetic variability expressed by the DNA profiles of the rice varieties and their mutant counterparts as well as in the yield performances. The study thus indicated that the source of NaN3 induced variants among the treated progenies were genetic in nature and hence heritable. However, further screening on promising mutant plants from this research should be done through successive generations to identify stable traits and variant that can perform optimally under saline conditions.