Sathee, L. | bioRxiv Science

bioRxiv2025

Identification of donor landraces for early vegetative stage salinity tolerance in wheat by employing multivariate selection indices

Soil salinity (EC of [≥]4 dS m-1) is a major abiotic stress leading to decreased crop production due to osmotic, ionic, and cellular ionic imbalance balance. The current study aims to identify salinity-tolerant wheat landraces by investigating morpho-physiological traits. Three hundred fifty wheat landraces and check lines were evaluated for salt stress (15 dS m-1) tolerance in a hydroponic set-up. The clustering analysis categorized 350 genotypes into four control and 15 dS m-1 conditions clusters. Across the multi-trait genotype-ideotype distance index (MGIDI), Smith Hazel Index (SHI), and Stress Susceptibility Index (SSI), seven genotypes were consistently identified as tolerant among the top 150. In comparison, 12 genotypes were consistently classified as least tolerant. These identified tolerant landraces serves as important resources and novel salt tolerance donors for wheat. The tolerant*sensitive, tolerant* tolerant check, crosses can be used for generating RIL populations to delineate genetic basis of salt tolerance of newly identified lines.

physiology↗

bioRxiv2025

Association of haplotypes of AAP family amino acid transporters with nitrogen response and nitrogen use efficiency in rice grown under hydroponics and field conditions

The low nitrogen use efficiency (NUE) of staple food crops like rice has both economic and environmental impact. Amino acids taken up from soil or synthesized in source tissues and transported to sink tissues influence plant development and NUE. Amino acid permeases (AAPs) mediate amino acid uptake and transport and influence plant development, yield and NUE. NUE is a complex trait critical for improving rice productivity under variable N supply. Amino acid permeases such as OsAAP3, OsAAP5, and OsAAP11 have been shown to function as negative regulators of NUE in Japonica rice, yet their roles in Indica rice remain to be fully elucidated. In this study, we evaluated selected Indica genotypes under contrasting N regimes--seedlings were tested under high nitrate (HN), high ammonium (HA), and low N (LN) conditions, and field performance was assessed under N120 (optimum N) and N0 (low N). Our aim was to relate performance differences to the SNP status in these three genes, thereby clarifying their influence on N uptake, assimilation, yield potential, and N stress adaptation. ARC 10799 had non-synonymous SNP in OsAAP3, OsAAP5 and OsAAP11. Rice accessions like "Local," "NCS901," and "Bhainsa Mundariya," showed superior biomass accumulation relative to MTU1010. Interestingly, the trend observed in the NUE calculated in seedling stage was similar to those proven in field evaluation and this proves that in general, genotypes with non-synonymous mutation in AAP3, AAP5 and AAP11 in comparison to Japonica showed better growth and N content. Data suggests an N induced regulation of physiological parameters and the changes in NUE parameters was at least in part, related to variation in biomass, plant height, photosynthesis and pigment content related parameters. The comparatively dissimilar trends in shown by different AAP haplotypes indicates the possibility of high or low correlation trait-wise, offering an opportunity to identify significant contrasts in a divergent set of AAP haplotypes. The previous reports and current findings opens new avenues and insights for improving rice yield, quality and NUE by changes in AAP haplotypes that occur naturally or created by precise genome editing.

plant biology↗