A Preliminary Study On Infertility Mechanism Of Salvia Miltiorrhiza In Sichuan Province

Belonging to Salvia Linn.species of Labiatae family,Salvia miltiorrhiza Bunge has been world-widely used as patent and traditional herbal medicine.The dried root of it was widely used to cure cardiovascular and cerebrovascular diseases.Thus,there is an increasing demand for cultivars of S.miltiorrhiza Bunge due to its important pharmacology functions.However,for its characteristic of sterility,the tubers of S.miltiorrhiza Bunge in Sichuan Province,China,are used in propagation,resulting in fewer medicinal materials available and lower crop yield and quality.Therefore,there is a need to identify factors affecting plant fertility of S.miltiorrhiza Bunge in Sichuan Province,China and optimise production.Here,the differences of plant morphology,pollen ultrastructure and physiology biochemistry characteristics of Salvia miltiorrhiza Bunge from the Sichuan and Shandong Province of China were observed.The report were as follows:1、On the basis of single-factor experiments through the method of pollen germination in vitro,Central Composite Design-response Surface Optimization Methodology was used to optimize the medium components to screen the optimal medium and culture condition for in vitro pollen germination of Salvia miltiorrhiza Bunge from Sichuan and Shandong Province of China.The optimal culture conditions of the response surface were as below.Salvia miltiorrhiza produced in Shandong:BK+temperature 21.87℃+sucrose 151.20 g/L+boric acid 273.83 mg/L,the germination rate was 90.30%under this condition and the actual germination rate was89.65%;Salvia miltiorrhiza produced in Sichuan:BK+temperature 26.28℃+sucrose133.81 g/L+boric acid 237.71 mg/L,the germination rate was 68.19%under this condition and the actual germination rate was 66.31%.It was obvious that the predicted value from an established mathematical model was close to the actual one,with relative deviation of-1.8%and-2.2%respectively.This suggested that the model could be used to optimize the pollen culture conditions.2、Through observation with stereomicroscope and fluorescence microscope,morphological characteristics of S.miltiorrhiza Bunge from Sichuan and Shandong Province of China showed obvious differences.The corollas of the latter were deep blue violet and the stamens appeared shorter but the former exhibited tropical indigo.Additionally,the inflorescence of S.miltiorrhiza Bunge from Sichuan Province was with thicker handles and more densely distributed flowers than that of Shandong Province.We also observed that some of the anthers locules of sterile was not cleaved the appropriate moment.3、With paraffin sectioning,comparative observations were made on the anatomy of anthers in flowers of and Shandong Province of China.Both of the chalazal megaspore developed into a polygonum type sac and had no difference between the two groups,indicating that Salvia miltiorrhiza Bunge from the Sichuan cultivators was not a female sterility.4、Differences of the morphology and anatomy of megaspore in flowers of Salvia miltiorrhiza Bunge from the Sichuan and Shandong Province of China were noticed by paraffin sectioning.The middle layer and the tapetum cells of S.miltiorrhiza Bunge from Sichuan Province were abnormal and showed a long delay to degradation,which resulted in the lack of nutrient absorbed from the middle layer and the tapetum cells at last.A delay in the development of microspore mother cell might also be associated with the pollen abortion of S.miltiorrhiza Bunge from Sichuan Province.5、Through with HPLC（High-performance liquid chromatography）detection,the differences of phytohormones concentrations of zeatin（ZT）,indole 3 acetic acid（IAA）,kinetin（KT）,zeatin riboside（ZR）,abscisic acid（ABA）and gibberellic acid（GA₃）in flowers of Salvia miltiorrhiza Bunge from the Sichuan and Shandong Province of China were detected.Specifically,the phytohormones concentrations of ZT and KT in anthers of Salvia miltiorrhiza Bunge from the Sichuan Province was significantly higher with high fluctuations but the IAA,ZR,ABA,and GA contents were lower than that from Shandong Province during the development of anther.The results indicated that abnormality of phytohormones concentrations in buds of S.miltiorrhiza Bunge from Sichuan Province might be closely related to the sterility.