The taxonomic status of Papilio maackii and P.syfanius has long been disputed.We conducted a molecular phylogenetic study to evaluate the taxonomic status of P.maackii and P.syfanius.A total of twenty-four P.maackii i...The taxonomic status of Papilio maackii and P.syfanius has long been disputed.We conducted a molecular phylogenetic study to evaluate the taxonomic status of P.maackii and P.syfanius.A total of twenty-four P.maackii individuals from six localities and sixteen P.syfanius individuals from two localities were analyzed.We sequenced the partial region of the CO-I gene（about 579 bp） and partial CO-II gene sequence（about 655bp） of the two species.The Kimura-2-Parameter distances among P.maackii and P.syfanius ranged from 0 to 0.6%.Fifteen haplotypes were obtained based on the combined data set.The results strongly supported that all P.maackii individuals and all P.syfanius individuals formed a large clade,and could not be divided into separated clades.This research indicated that the two species have only very recently undergone speciation.展开更多
Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of a...Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.展开更多
基金National Natural Science Foundation of China (30870359)Anhui Scholar Special Fund in Science and Technology (KJ2009B015)
文摘The taxonomic status of Papilio maackii and P.syfanius has long been disputed.We conducted a molecular phylogenetic study to evaluate the taxonomic status of P.maackii and P.syfanius.A total of twenty-four P.maackii individuals from six localities and sixteen P.syfanius individuals from two localities were analyzed.We sequenced the partial region of the CO-I gene（about 579 bp） and partial CO-II gene sequence（about 655bp） of the two species.The Kimura-2-Parameter distances among P.maackii and P.syfanius ranged from 0 to 0.6%.Fifteen haplotypes were obtained based on the combined data set.The results strongly supported that all P.maackii individuals and all P.syfanius individuals formed a large clade,and could not be divided into separated clades.This research indicated that the two species have only very recently undergone speciation.
文摘Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.
