AUTHOR=Kumar Kathiresan Pravin , Pushpam Ramamoorthy , Manonmani Swaminathan , Raveendran Muthurajan , Santhiya Subramanian , Senthil Alagarsamy 

TITLE=Enhancing stress resilience in rice (Oryza sativa L.) through profiling early-stage morpho-physiological and molecular responses to multiple abiotic stress tolerance

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 15 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1342441

DOI=10.3389/fpls.2024.1342441

ISSN=1664-462X

ABSTRACT=Under changing climatic conditions, crop plants are more adversely affected by a combination of various abiotic stresses rather than being impacted by a single abiotic stress. Therefore, it is essential to identify potential donors to multiple abiotic stresses for developing climate-resilient crop varieties. Hence, the present study was undertaken with forty-one germplasm accessions comprising native landraces of Tamil Nadu, pre-release lines and cultivars were screened independently for drought, salinity and submergence at the seedling stage during Kharif and Rabi 2022-2023. Stress was imposed separately for these three abiotic stresses on twenty-one-day-old seedlings and was maintained for ten days. The studied genotypes showed significant reduction in plant biomass (PB), relative growth index (RGI), relative water content (RWC), leaf photosynthesis, chlorophyll fluorescence, Chlorophyll Concentration Index (CCI) under drought followed by salinity and submergence. Stress tolerant indices for drought, salinity and submergence revealed significant variation for plant biomass. Further, a set of 30 SSR markers linked to drought, salinity and submergence QTLs have been used to characterize 41 rice germplasm accessions. Our analysis suggests, a significantly high polymorphism with 28 polymorphic marker had 93.40 percentage in 76 loci. The mean value of Polymorphic information content (PIC), heterozygosity index (HI), Marker index (MI) and resolving power (RP) were 0.369, 0.433, 1.140 and 2.877 respectively. Jaccard clustering grouped all the genotypes into two major and six sub-clusters. According to STRUCTURE analysis, all genotypes were grouped into two major clusters which is concurrent with a very broad genetic base (K = 2). Statistically significant marker-trait associations for biomass were observed for five polymorphic markers viz., RM211, RM212 (drought), RM10694 (salinity), RM219, RM21 (submergence). Similarly, significant markers for relative shoot length were observed for RM551 (drought), RM10694 (salinity) and ART5 (submergence). Notably, the genotypes Mattaikar, Varigarudansamba, Arupatham samba and APD19002 were identified to be the potential donors for multiple abiotic stress tolerance.Thus, identifying the genetic potential of germplasm could be useful for enhancing stress resilience in rice.