In-vitro selection of drought tolerant doubled haploid rice lines using polyethylene glycol (PEG)

The present study was conducted to determine the response of 55 double haploid (DH) rice lines developed for drought tolerance from the cross Swarna × IR159B in polyethylene glycol (PEG) induced drought stress under in-vitro conditions (DH lines named as double haploid rice lines-DRL). Drought stress was created using PEG-6000 at different level of external water potential. Analyzed seedling traits of DRLs showed significant differences in response to different PEG concentrations. A decrement in plant growth at seedling stage with the increase in PEG concentration was observed as expected. Among 55DRLs, 14 DRLs were found to be drought tolerant sustaining the stress level till -7.5 bar as of the tolerant checks. Further, Drought linked SSRs were also evaluated in developed rice lines. Out of 8 SSRs, RM55 (R2 value- 13.5%) and RM259 (R2 value- 13.9%) found to be exhibiting significant association with the shoot/root ratio at - 7.5 bar stress level. Out of 14 DRLs, 9 DRLs were found to be showing drought tolerant in phenotypic and genotypic screening. Hence, PEG induced stress screening method used in this study will serve as the baseline for screening of rice lines for drought tolerance at very early stage without exploitation of much resource.