Development of High Regeneration Frequency Mutagenic Lines Using Various Explants and Screening For Yield and Drought Tolerant Trait in Wheat (Triticum Aestivum L.)

Abstract

Being a main staple crop of India wheat has a major role in country daily needs for people needs. There are several methods exists to improve wheat crop. Among them plant tissue culture and mutagenic tools are gaining momentum in current scenario because of their innovativeness. The objective of the current study was to create drought tolerant lines via developing an efficient in vitro regeneration protocol. The impact of plant growth hormones (PGR) on callus induction response and regeneration frequency has been evaluated in the present investigation. Three wheat genotypes of different background and diversity in their gene pool exist were selected. Mature embryos were selected due to their availability all the time. MS media was used as a culture media in the present study. In comparison to the other genotypes HD3059 and UP2338, the C 306 genotypes attained the good callus induction no premature germination at the fourth week of observation. Among all three genotypes used, genotype UP2338 showed good regeneration. Sodium NitroPrusside (SNP) was used in the present study to check it synergistic effect with other PGRs which were standardized earlier, on callusing and regeneration in all the three selected genotype. 20μM SNP concentration was found suitable to enhance the callus induction and 10μM concentration enhances the regeneration. Further, upon treating explants (wheat seeds) with different doses of mutagens (EMS, UV and Gamma), the explants of genotype HD3059 responded well to callus induction. The most suitable EMS concentration T3E0 (0.5mM EMS, 0% PEG for 0.5 hours) followed by highest regeneration (71.10%) when subjected to 10% water stress by adding PEG in the media and gave 2.33 shoots per callus as explants. Similarly, 2h exposure of wheat seeds of genotype HD 3059 with UV light found very effective and recorded the highest regeneration (66.61%) when inducing drought stress to the culture media. The three genotypes HD 3059, C 306, and UP 2338, however, demonstrated the highest regeneration to occur when exposed with gamma ray (20Gy) irradiation in the current study. The biochemical evaluation of the mutagenized lines that had survived drought stress involved proline estimation and confirmed the results. In order to determine whether treatment of mutagens (EMS, gamma and UV radiation) resulted in any changes in wheat regeneration, molecular analysis was conducted. The mutant plants were regenerated for this purpose, and ISSR primers were employed to examine the normal and mutant plants. The ISSR markers UBC 810, UBC 876, and UBC 848 were determined to have the high rate of mutation, as seen by their banding patterns. PIC values range from 0.34 (UBC 810) to 0.67 (UBC 826) with an average of 0.49 in ISSR analysis. The current study may be helpful in creating transgenic lines in future with improved desired traits in wheat.