Optimization of extraction of phenolics from leaves of Ficus virens

In this research,the conditions for extraction of phenolics from leaves of Ficus virens were optimized using response surface methodology(RSM).The extraction abilities of phenolics(EAP) and flavonoids(EAF),the 2,2-diphenyl-1-pierylhydrazyl(DPPH) free-radical scavenging potential,and the ferric reducing/antioxidant power(FRAP) were used as quality indicators.The results of single-factor experiments showed that temperature,ethanol concentration,extraction time,and the number of extraction cycles were the main influencing variables,and these provided key information for the central composite design.The results of RSM fitted well to a second degree polynomial model and more than 98% of the variability was explained.The ideal extraction conditions for EAP,EAF,DPPH free-radical scavenging potential,and FRAP were obtained.Considering the four quality indicators overall,the ideal extraction conditions were 58% ethanol at 57 °C for 37 min with three extraction cycles.At the ideal extraction conditions,the values of EAP,EAF,DPPH free-radical scavenging potential,and FRAP were 5.72%,3.09%,58.88 mg ascorbic acid equivalent(AAE)/g dry weight(DW),and 15.86 mg AAE/g DW,respectively.In addition,linear correlations were observed between EAP,EAF,and antioxidant potential.

三种常用道路绿化植物根系生长状况研究

以黄葛树(Ficus virens var.sublanceolata)、小叶榕(Ficus microcarpa L.)和春鹃(Rhododendron pulchrum Sweet)为试验对象,通过挖取南向1 m×1 m×1 m的土壤剖面观察其根系的分布状况,发现在距树干南向1 m处,黄葛树88.1%及以上的根系主要分布于0~60 cm深的土层中,小叶榕92.0%及以上的根系主要分布于0~60 cm深的土层中,春鹃43.4%及以上的根系主要分布于0~30 cm深的土层中;3种植物的须根在石骨子碎块和砖块缝隙中可发育成扁平状或云片状,其根系结构特点更适合重庆市园林绿化土壤的现状。

Seed and Wasp Production in the Mutualism of Figs and Fig Wasps

Figs (Moracea: Ficus) and fig wasps (Hymenoptera: Chlocloids: Agaonideae) depend on each other to complete their reproduction. Monoecious fig species and their pollinating wasps are in conflict over the use of fig ovaries which can either produce one seed or one wasp. From observation on Ficus virens Ait., we showed that female flowers with outer layer of ovaries (near to the wall of syconium) had no significant difference from that with inner and interval layer of ovaries (near to the syconium cavity), in which most seeds and wasps were produced. This meant that fig tree provided the same potential resource for seed and wasps production. Observation indicated that there was usually only one foundress in syconium at female flower phase and no com- petition pollinators. Measurement of the style length of female flowers and the ovipositor of pollinators indicated that most ovaries could be reached by pollinator’s ovipositor. However, at the male flower phase, production of seeds was significantly more than that of wasps including non-pollinating wasps but there was no significant difference between seed and pollinating wasp production when without non-pollinating wasps produced. This result indicated that non-pollinating wasps competed ovaries not with seeds but with pollinating wasps for ovipositing. Bagged experiment showed that the sampling fig species was not self-sterile which was important for figs and wasps to survive bad season. Seed production in self-pollinated figs was not significantly different from total wasps in- cluding non-pollinating ones. This might be related with the weaker competition among wasps since bagged figs were not easy to reach by wasps from outside.