Project description:The transfer of herbicide resistance genes by pollen is a major concern in cross-pollinated species such as annual ryegrass (Lolium rigidum). A two-year study was conducted in the greenhouse, under favorable conditions for pollination, to generate information on potential maximum cross-pollination. This maximum cross-pollination rate was 56.1%. A three-year field trial was also conducted to study the cross-pollination rates in terms of distance and orientation to an herbicide-resistant pollen source. Under field conditions, cross-pollination rates varied from 5.5% to 11.6% in plants adjacent to the pollen source and decreased with increasing distances (1.5 to 8.9% at 15 m distance and up to 4.1% at 25 m in the downwind direction). Environmental conditions influenced the cross-pollination both under greenhouse and field conditions. Data were fit to an exponential decay model to predict gene flow at increasing distances. This model predicted an average gene flow of 7.1% when the pollen donor and recipient plants were at 0 m distance from each other. Pollen-mediated gene flow declined by 50% at 16.7 m from the pollen source, yet under downwind conditions gene flow of 5.2% was predicted at 25 m, the farthest distance studied. Knowledge of cross-pollination rates will be useful for assessing the spread of herbicide resistance genes in L. rigidum and in developing appropriate strategies for its mitigation.
| S-EPMC4918886 | biostudies-literature
Project description:RNA sequencing of Lolium rigidum
Project description:Heavy metal cadmium (Cd) affects seriously crop growth, quality and yield, and has potential threats to human safety. We found the difference of two ryegrasses (Lolium multiflorum Lam.), a high-Cd tolerance (LmHC) and a low-Cd tolerance (LmLC) cultivars , in response to cadmium stress. The germination rate, plant growth, and fresh weight of LmHC were much better than that of LmLC. So we use RNA sequencing to investigate the differentially expressed genes(DEGs) about cadmium response between LmHC and LmLC. Real-time quantitative PCR analysis showed that the same DEGs of LmLC and LmHC had obviously difference expression level under Cd treatment. It was suggestion that differential expression of DEGs might be involved in regulating Cd tolerance, accumulation and translocation.These results will be helpful for understanding the underlying molecular mechanism in Cd toxicity and provide references for improving the ecological environment through genetic improvement.