Identification of genetic factors governing drought tolerance in wild and domesticated tetraploid wheat

Identification of stripe rust resistance loci in Gansu wheat landraces using genome-wide association analysis

Genomics-Assisted Breeding for Drought Tolerance in Wheat (Triticum aestivum L.): Recent Advances and Future Prospects

Overall, transcription factors from the DREB, NAC, MYB, and WRKY families are still considered the primary regulatory targets, but CRISPR/Cas-based gene editing is now able to provide precise, multiplex gene modifications in polyploid wheat.

Genetic Dissection and Fine-Mapping of QTL for Salinity Tolerance at the Reproductive Stage on Chromosome 2 of Rice Variety Nona Bokra

Soil salinity is a major constraint limiting rice productivity, particularly at the reproductive stage. To elucidate the genetic basis of reproductive stage salinity tolerance, this study validated and fine-mapped quantitative trait loci (QTL) for yield-related traits using a salinity-tolerant line SL506, identified through screening of Nona Bokra–CSSLs in a Koshihikari background. In 2016, the F2 population derived from SL506/Koshihikari was evaluated under long-term salt stress; three QTLs associated with plant dry weight, panicle number, and grain weight were detected on chromosome 2. In 2023, validation analysis using F3 individuals confirmed the presence of these QTLs. Subsequent fine-mapping using F4 near-isogenic lines (NILs) delimited the QTL to a 1.7 Mb interval and high-resolution mapping using an F5 recombinant population progressively refined it to a 473 kb genomic region containing 69 annotated genes. Variant Effect Predictor analysis identified 15 deleterious nonsynonymous variants (SIFT < 0.05) in six candidate genes. Based on annotated gene functions, predicted variant effects, and their membership in stress-related gene families, OsPP2C24, OsFbox102, and OsWAK14 were suggested as the most promising candidate genes underlying qPDW2. These findings provide insights into the genetic basis of reproductive-stage salinity tolerance from valuable resources for the future improvement of salt tolerance and yield stability in rice.

Association of SSR Markers on 2D Chromosome of Bread Wheat with Drought Tolerance

Exploring the Diversity of Blast Resistance Genes in Rice Lines Using PCR-Based Functional STS Markers

Rice blast, caused by Pyricularia oryzae (syn. Magnaporthe oryzae), remains one of the most destructive diseases of rice worldwide. Developing resistant varieties is a sustainable strategy for disease management, and information on the diversity of blast resistance genes is important for selecting breeding parents. This study evaluated the effectiveness of functional sequence-tagged site (STS) markers for resolving genetic diversity among advanced rice lines derived from multiple-cross populations. A total of 104 genotypes, comprising 100 advanced lines and four parental varieties (Ciherang, Inpari 13, Inpari 10, and Situ Bagendit), were analyzed using eight gene-specific STS markers associated with four blast resistance genes (Pii, Pia, Pikp, and Pita). Polymorphism information content (PIC) values ranged from 0.80 to 0.96, with a mean of 0.89. UPGMA cluster analysis separated the genotypes into two major groups at a similarity coefficient of 0.90, although most lines occurred in one group and lines with the same parental background were distributed among different subgroups. Observed heterozygosity was low (Ho = 0.09), indicating limited resolution for distinguishing closely related lines despite the high PIC values. Functional STS markers were informative for detecting allelic variation but were insufficient for resolving fine-scale relationships within this genetically narrow breeding population. Combining marker analysis with phenotypic evaluation and higher-resolution markers is therefore recommended to improve selection for blast resistance.

Phenotypic variation in drought response for a double-haploid population of bread wheat (Triticum aestivum)