SCREENING OF SALINE TOLERANT RICE GENOTYPES (Oryza sativa L.) AT JUVENILE STAGE

Abstract

An experiment was conducted at the Department of Genetics and Plant Breeding Laboratory of Hajee Mohammad Danesh Science and Technology University, Dinajpur during Boro season of 2017. Twenty four rice genotypes including 20 land races were screened to investigate the germination and seedling morphological characteristics against different levels of salt stress. The saline conditions were created in laboratory using five different treatments of NaCl i.e., 0, 4 dS/m, 8 dS/m, 12dS/m and 16 dS/m. The experiment was laid out in completely randomized design (CRD) with three replications. Several parameters such as germination percentage, number of root, shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight, chlorophyll content and proline content of rice seedlings were studied. Most of the traits were evaluated at 14 days after sowing of seeds on all experimental genotypes. The genotypes differed significantly for all traits. Furthermore, the treatment effects were also significant for all studied traits. It was revealed that with increase of salt stress germination percentage, germination rate, seedling vigor index, number of roots, shoot length, root length, total length of the plant, shoot fresh weight, root fresh weight, total fresh weight, root dry weight, shoot dry weight and total dry weight were decreased in most of the genotypes. Phenotypic coefficient of variation was higher than the genotypic coefficients of variation indicating environmental influence on the traits. High heritability coupled with high to moderate genetic advance as percent of mean was observed for all the traits except number of leaves and root dry weight. These characters can be further used for selection of superior genotypes. In this study, the interrelationship between studied traits and its contributing characters were determined by correlation matrix. The result of the correlation co-efficient among measured traits under control and saline conditions showed that the traits had a significantly positive correlation with corresponding traits. According to the experimental result based on different traits the superior genotype was Pokkali 8948 followed by FL-478, Chota lona kuchi and Bara lona kuchi among the 24 genotypes. These landraces could be designated as salt tolerant from studying it. This finding could be confirmed by further in vivo or field condition research as well as marker assisted breeding research. Therefore, Pokkali 8948, FL-478 and Chota lona kuchi could be helpful to find out salt tolerant gene and to develop salt tolerant variety