水稻茄丝核菌SRAP引物筛选与体系优化

为了应用新型的SRAP分子标记技术分析水稻茄丝核菌基因多态性和探究基因多态性与采集来源及水稻品种之间的关系,以吉林省不同地理位置的3株水稻丝核菌为材料,从100对SRAP引物中筛出较理想的引物16对,并对影响SRAP反应的Mg²⁺、dNTPs、引物、Taq DNA聚合酶、模板DNA浓度及两次退火温度等条件进行了优化,建立了适宜于该菌的SRAP反应体系,25 μL的反应体系包含2.5 mmol/L Mg²⁺、0.15 mmol/L dNTPs、0.8 μmol/L引物、1.5 U Taq DNA聚合酶和80 ng模板DNA。利用24株水稻丝核菌对优化后的SRAP反应体系进行了验证,结果表明该反应体系稳定可靠,能够有效地用于水稻茄丝核菌的遗传多样性分析。     

Biotransformation of clomazone in rice (Oryza sativa) and early watergrass (Echinochloa oryzoides)

Rice (Oryza sativa), a relatively tolerant species, and early watergrass (Echinochloa oryzoides; EWG), a relatively susceptible species, were exposed to ¹⁴C-labeled clomazone to determine accumulation, biotransformation, and mass balance. On a total mass basis, rice absorbed more clomazone than EWG (p < 0.05), but on a nmol/g basis, there was no significant difference between the two species (p > 0.05). Rice contained more extractable ¹⁴C residues (7.7 ± 0.5 vs. 4.8 ± 0.5 nmol in rice vs. EWG, respectively; p < 0.5), but the concentration in EWG was significantly higher (4.2 ± 0.5 vs. 1.8 ± 0.1 nmol/g in EWG vs. rice, respectively; p < 0.01). More metabolized residue was measured in EWG compared to rice (84.1% vs. 67.9%; p < 0.01). Both species produced hydroxylated forms, β-d-glucoside conjugates, and several other unidentified polar metabolites, but EWG generally produced higher metabolite concentrations. The concentration of the suspected active metabolite, 5-ketoclomazone, was significantly higher in EWG vs. rice (21 ± 2 vs. 5.7 ± 0.5 pmol/g, respectively; p < 0.01). Differences in sensitivity to clomazone between rice and EWG appear to be due to differential metabolism, but in this case the more susceptible EWG qualitatively and quantitatively metabolized more clomazone than the more tolerant rice. This is consistent with the action of a metabolically activated herbicide. This metabolic difference could be exploited to develop herbicide safeners for use with clomazone.