High sensitivity of rice coleoptile elongation length to exogenous gibberellin is a beneficial trait to utilize superior rice cultivars that could not be used originally under water direct-seeded conditions. In the present study, we mined favorable alleles for the trait by combining the phenotypic data of 358 rice accessions with their genotype data of 262 simple sequence repeat (SSR) markers via genome wide association mapping method. Totally, 17 SSR marker loci significantly associated with gibberellin sensitivity index (GSI) of coleoptile elongation length under 10 cm depth of water, were detected by general linear model and mixed linear model across two years, with percent phenotypic variation explained larger than 10%. Twenty nine favorable alleles for GSI on the 17 loci were discovered with phenotypic effect value (PEV) larger than 0.1 cm/cm and RM6869-110 bp showed the largest PEV (0.27 cm/cm). Based on PEV of marker-alleles having positive effects on GSI, seven parental combinations were predicted to improve GSI. In addition, 7 loci for GSI were co-located with loci associated with coleoptile elongation length per se, and one locus (RM1182 on chromosome 5) was co-located with that associated with coleoptile elongation length after gibberellin-soaked seed, under germination condition of 10 cm depth of water. These favorable allele(s) could be used to improve two target traits simultaneously.

Rice (Oryza sativa L.) has an impressive range of phenotypic and genetic diversity, making it an important crop for global food security. Since rice phenotypic and genetic diversity are essential for enhancing the sustainability of rice production, an understanding of these variations is crucial for breeding efforts. Numerous factors, such as plant height, panicle number, grain properties, etc., exhibit phenotypic diversity in rice. Moreover, genetic diversity is essential for breeding and enhancing rice in multiple manners. This research investigates the phenotypic diversity of thirteen promising lines relative to their parents. Since the genetic effect reflects the plant’s phenotype, forty SSR markers were used to investigate the genotypic diversity. Generally, six promising genotypes produced much better grain yields than their parents. Across two years, the number of filled grains panicle⁻¹ and the number of unfilled grains panicle⁻¹ had the highest phenotypic and genotypic coefficients of variability percentage. The challenges towards novel variety with distinct characteristics were met in several promising lines under examination, which showed a significant and positive association between the grain yield and the number of panicles per plant, the number of filled grains per panicle, and the 1000-grain weight. Furthermore, five SSR markers were discovered to be polymorphic during the genetic diversity investigation, and the genotypes were classified into five clusters based on SSR marker data. The findings, together with further details, can be used to release novel and unique varieties.

Background Quinclorac- main herbicide targeting to barnyard grass, has been used for decades in rice fields. Echinochloa species have been reported evolving into quinclorac resistance.Objective: Quinclorac resistance and its mechanism remain undisclosed in Echinochloa oryzoides (Ard.) Fritsch that needs to be uncovered. Methods Dose-response assays were performed, followed by ethylene synthesis, and related enzyme activities along with gene transcription were studied. β-CAS activity and its molecular docking were investigated. Results E. oryzoides evolved into 21 times resistance to quinclorac [...] Abstract Background Quinclorac- main herbicide targeting to barnyard grass, has been used for decades in rice fields. Echinochloa species have been reported evolving into quinclorac resistance.Objective: Quinclorac resistance and its mechanism remain undisclosed in Echinochloa oryzoides (Ard.) Fritsch that needs to be uncovered. Methods Dose-response assays were performed, followed by ethylene synthesis, and related enzyme activities along with gene transcription were studied. β-CAS activity and its molecular docking were investigated. Results E. oryzoides evolved into 21 times resistance to quinclorac