SCREENING OF SALINE TOLERANT MAIZE (Zea mays L.) INBRED LINES 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 November, 2017. Here, twenty maize inbred lines were screened to investigate them against different levels of salt stress on germination and seedling morphological characteristics. The salt stress conditions were created in laboratory conditions using three different levels of NaCl concentration with a control such as 0, 5, 10, and 15 dSm-1 . The experiment was laid out in completely randomized design (CRD) with three replications. Most of the traits were evaluated at 14 days after sowing of seeds on all experimental genotypes. The results of the analysis of variance revealed significant differences among the genotypes and treatments for all the characters studied viz. germination percentage, number of leaves per plant, number of roots per plant, shoot length, root length, shoot fresh weight, root fresh weight, root dry weight, shoot dry weight, root shoot fresh weight ratio except root shoot dry weight ratio. The genotype x treatment interaction was significant for most of the characters except root shoot fresh weight ratio. According to some genetic parameter studied, there was significant variability existed among the genotypes for the all characters. Here, high heritability along with high magnitude of genetic advance in percentage of mean was recorded among most of the traits. Significant correlation was found among most of the characters such germination percentage, number of leaves per plant, shoot length, shoot fresh weight, shoot dry weight, root length, number of roots per plant, shoot dry weight and root dry weight under among them both control and stress condition. This indicated that simultaneous selection of all these characters was important for screening of maize genotype. Considering all the characters for all genotypes when these raised up to seedling stage without any salt stress (T0), it was found that the genotype ML05 stood first position in performance and was closely followed by ML11 and ML19. When these genotypes were exposed under low salt stress (T1), the genotype ML11 showed superior performance among other genotypes in respect of all the traits, which was followed by ML05 and ML28. In case of mild salt stress (T2), the genotype ML28 exhibited greater performance for all studied traits that was followed by ML19, ML10, ML26. When the genotypes exposed to severe stress conditions (T3), it was observed that the genotype ML28 performed best among all the genotypes which was followed by ML05 and ML11 for germination percentage, number of leaves per plant, number of roots per plant, shoot length, root length, shoot fresh weight, root fresh weight, root dry weight, shoot dry weight, root shoot fresh weight ratio and root shoot dry weight ratio. According to the ranking based on all treatments and studied traits, the genotypes ML28, ML19, ML10, ML05, ML26 performed better compared to other genotypes. Again, the results of Salt Tolerant Index (STI) indicated the superiority in the ML28 closely followed by the genotypes ML26, ML24, ML10, ML06, ML11, ML12, ML05, ML19 in highest salinity level (T3). These inbred lines could be designated as salt tolerant from the study. This finding could be confirmed by further in vivo or field condition research as well as marker assisted breeding research. Therefore, ML28, ML19 ML05 ML10, ML11 and ML26 could be helpful to find out salt tolerant gene and to develop salt tolerant variety in near future