| Wild vegetables mainly distribute in natural conditions withoutmuch pollution, known as "pollution-free green foods". Cryptotaenia japonica Hassk is aperennial wild vegetable, belonging to the family Umbelliferae, native to eastern Asiaand temperate North America. Cryptotaenia japonica has very high value of health care. In the present paper,its climate adaptation range, genetic diversity, cultivation conditions, volatile oil and the influences of heavy metals on its growth and content of corresponding elements were studied. The main results are as follows:(1) Based on the geographical distribution data of C. japonica in China and 12 climate factors, the potential and suitable distribution range of C. japonica in relation to climate were predicted by using Max Ent model and Arc Gis 9.3. The results show that, Cryptotaenia japonica has highest climate adaptation index in Zhejiang(54.53), followed by Hunan(50.47),Jiangxi(48.96). The indices for Hebei, Hainan, Liaoning, Inner Mongolia, Beijing, Jilin, Tianjin, Xinjiang,Qinghai,Heilongjiang vary from 9.01 to 9.23, significantly lowerthan those of Zhejiang, Hunan and Jiangxi. The main factorson influencing the distribution of Cryptotaenia japonica Hassk are average rainfall of the hottest and coldest quarter,the quarterly average temperature, average temperature of dry wet quarter, the temperature difference between day and night temperature,and seasonal temperature variation.(2) To study the genetic diversity of Cryptotaenia japonica Hassk, six populations including 70 individuals were collected from Mt. Beishan(Jinhua, Zhejiang), Mt. Qinliangfeng(Linan, Zhejiang), Mt. Dapanshan(Panan, Zhejiang), Chuanghua(Linan, Zhejiang) and Fengxian(Shanghai, a cultivated population). Nine inter-simple sequence repeat(ISSR) primers were selected from 95 primers by our pre-experiment. A total of 149 Loci were amplified, which could be applied to analyze the diversity of the species. Among the 149 Loci, 136 are polymorphic, accounting for 91.28% of the total. Analyses shows that Nei’sgene diversity index(H), Shannon’s information index(I)were 0.1971 and 0.3086, respectively. The Nei Gst is 0.5993 for the six populations, showing that 59.93 % genetic differentiation existed among different populations,while 40.07% within the populations. The observed number of alleles is 1.9128, the effective number of alleles is 1.3258. The gene flow among the six populations is relatively low, being 0.3343. That is to say, a weak genetic differentiation has occurred among Cryptotaenia japonica populations. The cluster analysis and ordination based on ISSR data by using Bary-Curtis coefficients clearly showed geographical differentiation existed, which corresponds with genetic differentiation.(3) The difference in volatile oil between fresh and dried Cryptotaenia japonica samples wascompared. It was found that the composition of volatile oil content from the fresh material is similar to that of dry material, but the content of the former is higher than the latter, though not reaching statistical different level. Meanwhile,the content of volatile oil of C. japonicaextracted by using Soxhlet extractionmethod was higher than by using rotary evaporation method,but the composition by the former method is smaller than by the latter method, because a low concentration of volatile oil ingredients were determined from the recycled diethyl ether after extraction by using rotary evaporation method. The results showed that the application of rotary evaporation method to extract volatile oil of Cryptotaenia japonica is not an ideal method. The influences of different solvent extraction on volatile oil content of Cryptotaenia japonicawere determined. Results show that the main components of volatile oil are eicosanoid with petroleum ether as extraction solvent, and the content of alkanes was lower, and the component is less than that by using ether as solvent. Experiments showed tha the main components of volatile oil of C. japonica are Stigmast-5-en-3-ol(14.66%, relative content), oxide II(13.81%), pinane(8.64%), seventeen alkyl(1.94%), 3,7,11,15-Tetramethyl-2-hex(3.94%), palmitic acid(3.87%), eighteen alkyl(2.42%), eighteen alkyl(2.42%),Hexadecane(2.24%) etc..(4) The Fv/Fm, light quick response cuve, initial slope and half saturation light intensity of C. japonica treated with iron salt at different concentrations, cultivated on different strates and under aquatic cultivation condition were determined. Our results showed that additional iron salt was able to promote C. japonica grow. When treated with Fe at 5, 15 and 45 mg.kg-1,the quantum efficiency of Cryptotaenia japonica increased by 20%,and Fv/Fm also increased by 44%. With the increase of the ratio of peat soil in culture medium,the Fv/Fm of Cryptotaenia japonica also increased(p < 0.05),the value increased by 3%. Whenthe ratio of Peat soil in the medium exceeded 100%, the value decreased. Analyses based on the data oflight energy utilization,the quantum efficiency of C. japonica would increase by 60% when the plants cultived in the environments added disinfected fowl dung at a content of 10kg/m2. Therefore,thefowl dung at a certain content would promote the growth of C. japonica. The study based on the tests of exogenous iron experinment showed that the leaves and stems of C. japonica had highest absorption capacity for iron.(5) The chlorophyll fluorescence characteristics(including Fv/Fm, the initial slop and half saturation light intensity), the content of Pb and Cd of C. japonica were determined, which were under stress conditions resulted from Pb and Cd. The quantum efficiency decreased by 17% when its plants were treated with Pb at 2000 mg.kg-1, compared with the control. The photosynthesis were completely inhibited when they were treated with Pb at 200 mg.kg-1 together with Cd at 1.2 mg.kg-1。With the increase of the content of Cd and Pb in environments, both the leaf length and individual height decreased. While treated with Cd at lower content, these indices increased, by 7% for individual height. When beyond a content threshold of Cd, the individual height decreased, up to by 14%.(6) Pb absorption content of C. japonica treated with Pb at 0, 200, 500, 1000 and 2000 mg.kg-1were measured. With the increase of Pb in cultivated environemts, the content of Pb in the plants of C. japonica increased, being 86 times as the control for its roots, 7 time for its stem, and 24 for its leaves;The average content of Pb in C. japonica material collected from Beishan Mt., Jinha, Zhejiang is 1403 mg.kg-1, much higher than that under cultivated condition, the latter being about 80 mg.kg-1. Our determination showed that the content of Pb is distinctly higher in roots than in leaves, while lowest in stems. The Pb content of C. japonica treated with Pb at 12 mg.kg-1 was four times of the control for roots and stems,and three times for leaves. The case is similar for Cd, whose content was highest in the roots of C. japonica, then in leaves, and lowest in stems. Under experimental content of Cd, though the content of Cd is highest in root, but not reaching its saturation point, while with the increase of Cd, the content of Cd in leaves and stems reduced, revealing a low endurance of leaves and stems of C.japonica. We speculated that its leaves and stems were injured. |
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