不同浓度的萘嵌戊烷和秋水仙素对‘黔通2号’果实农艺性状的影响研究

本文通过探究喷施不同浓度萘嵌戊烷和秋水仙素对白木通优良品种‘黔通2号’果实农艺性状的影响,为生产中筛选提高‘黔通2号’可食性的化学诱变剂提供参考。本研究分别采用不同浓度的秋水仙素(0.1%、0.15%、0.2%)和萘嵌戊烷(0.1%、0.15%、0.2%、0.25%)喷施6年树龄的‘黔通2号’盛花期花序,分析成熟期果实农艺指标变化。研究结果表明,0.2%秋水仙素处理较对照果皮百分率显著降低7%,单果重、果实横径、单果果肉鲜重和可食率分别显著增加9%、10%、23%和11%,可食率增加至39.67%;0.25%萘嵌戊烷处理综合表现最优,与对照相比果实纵径显著减小10%,可食率显著提高22%,提高至42.66%;果皮百分率、单果含籽率和种子数分别显著降低11%、15%和24%。通过实验得知,喷施适宜浓度萘嵌戊烷可显著提高‘黔通2号’的果实可食性,在确保食用安全的前提下可在生产中推广。

Impact of dissolved humic acid on the bioavailability of acenaphthene and chrysene assessed by membrane-based passive samplers

Dissolved organic carbon (DOC) is known to reduce the bioavailability of hydrophobic organic compounds (HOCs) in aqueous environments. This reduction occurs as a result of adsorption to DOC, apparently reducing the freely dissolved concentration of HOCs. In the present study, triolein-embedded cellulose acetate membrane (TECAM) and Japanese medaka (Oryzias latipes) were used to measure the uptake of acenaphthene and chrysene in the presence of commercial humic acid (HA) at different concentrations (0―15 mg C·L-1) under controlled laboratory conditions. Apparent uptake rate constants for PAHs in TECAM and medaka were compared and DOC-water partition coefficients (KDOCs) of two PAHs were calculated with different sampling methods by model fit. Results showed that HA present in water significantly reduced the uptake of PAHs in TECAM and medaka. The obtained values of log KDOC of acenaphthene and chrysene measured by TECAM were 4.63 and 5.83, respectively, whereas biologically determined values were 4.52 and 5.76, respectively. These log KDOC values were comparable to earlier published KDOCs toward commercial HA, thereby indicating that TECAM accumulated only the freely dissolved fraction of chemicals and uptake PAHs in a manner similar to that of fish. All these results suggested that the TECAM method can provide a good means for assessing the impact of DOC on bioavailability of PAHs in the aqueous environment.