Appropriate Concentration of ASA for Regulating Browning and SE of Mature Embryos of Fraxinus mandshurica
Ascorbic acid(ASA)can regulate explant browning and induction rate in somatic embryogenesis(SE)of Fraxinus mandshurica.In order to confirm the optimum ASA treatment concentration,mature cotyledon explants from different stock trees collected at different sites were treated with ASA in further detailed gradient of concentrations based on former research results,and the treatment effects were analyzed.The results showed that low concentrations(5～20 mg/L)and high concentrations(150～200 mg/L)of ASA could inhibit the browning and somatic embryogenesis of the explants,90～120 mg/L ASA could promote the browning and somatic embryogenesis of the explants;110 mg/L ASA was the best treatment concentration for somatic embryogenesis of mature zygotic embryo cotyledon explants of Fraxinus mandshurica,the occurrence rate of somatic embryos was increased by 65.05％,the browning time and the somatic embryo occurence time was shorten 5 and 9 days respectively,compared with the control;Most of the somatic embryos occured on the 3/4 browned explants,which occupied 65.17％of total explants with somatic embryogenesis;only 0.67％somatic embryos occured on the non-browning explants;There were significant differences in somatic embryogenesis among different mother trees in the same and different collecting sites,with a induction rate order of Harbin Forest Farm of Northeast Forestry University＞Qingshan Seed Orchard at Weihe＞Jinshan Seed Orchard at Linjiang;and the highest difference of induction rates of explants from different mother trees at the same collecting site could reach 4.08 fold.Therefore,it could be deduced that the effects of somatic embryogenesis and browning of Fraxinus mandshurica mature cotyledon explants was significantly depended on the concentration of ascorbic acid and mother tree sources;treatments with proper ASA concentrations could effectively increase the induction rate and shorten the occurence time of somatic embryos at the same time of increasing browning rate and shorten browning time of the explants of Fraxinus mandshurica.
NETL
NSTL
万方数据
维普
