| Among several kinds of prevention and. treatment of heavy metals at present, phytoremediation technology has more advantages with, environment-friendly and low-cost, Ramie (Boehmeria nivea (L) Gaud.), also named "China grass", belongs to Urticaceae Boehmeria, is a perennial fiber crop. Ramie not only has the characteristics of barren resistance, large roots, strong reproductive ability, but also has a strong tolerance and enrichment of heavy metals, which makes it an ideal plant to renovate heavy metals from contaminated soil.This paper mainly has worked on three aspects as follows.1) the study of ramie tolerance of Cd; 2) the study of ramie for its enrichment of Cd; 3) the study of anthocyanin response mode in ramie under Cd stress.The main results were as follows:This result suggested that ramie can tolerate a concentration to 153 mg/kg Cd stress. Under the stress of high concentration of Cd (153 mg/kg), "Lengshuijiang wild ramie" showed the characteristics of the strong tolerance and enrichment of Cd, which was compared with "Tushun qingma", "Xiangzhu III" and "Liuyang wild ramie". "Lengshuijiang wild ramie ’"s tolerance index was 0.7, the enrichment coefficient was 0.55; While "Fushun qingma", "Xiangzhu III" and "Liuyang wild ramie’"s tolerance index were 0.6; the enrichment coefficient was 0.49,0.40 and 0.23 respectively. We obtained a new germplasm with high tolerance and high enrichment to heavy metal "Cd", which is called "Lengshuijiang wild ramie"There were two cultivated ramie varieties and two wild ramie germplasm, the variation of Cd transport coefficient of Plant aboveground was 0.26-2.07. Under the stress of two concentration of Cd (54mg/kg and 153 mg/kg), the Cd transport coefficient of "Liuyang wild ramie" were both less than 1.Under the stress of concentration of Cd 54mg/kg, the Cd transport coefficient of "Lengshuijiang wild ramie" was less than 1, while the stress of concentration of Cd 153mg/kg, the Cd transport coefficient of "Lengshuijiang wild ramie" was more than 1. Under the stress of two concentration of Cd (54mg/kg and 153 mg/kg), the Cd transport coefficient of "Fushun qingma"and "Xiangzhu III"were both more than 1.Under the pot expriment condition of soil culture, with the stress of concentration of Cd 54mg/kg, "Fushun qingma" showed stronger tolerance than "Xiangzhu Ⅲ", "Fushun qingma’"s tolerance index was 0.9, while "Xiangzhu Ⅲ"s tolerance index was 0.7; with the stress of concentration of Cd 54mg/kg, "Xiangzhu III" showed stronger tolerance than’Tushun qingma", "Fushun qingma"’enrichment index was 0.51, while "Xiangzhu Ⅲ’"s enrichment index was 0.7; with the stress of concentration of Cd 153mg/kg,both "Fushun qingma’"s and"Xiangzhu Ⅲ"’s tolerance index were 0.6, "Fushun qingma"’enrichment index was 0.49, while "Xiangzhu Ⅲ’"s enrichment index was 0.4, "Fushun qingma" showed stronger enrichment than "Xiangzhu III"Under hydroponic conditions, in the five Cd stress environment(0mg/L、22mg/L、 125mg/L、175mg/L and 250mg/L), except the stress of concentration of Cd 125mg/L,the tolerance index of "Fushun qingma" was greater than the tolerance indes of Xiangzhu III";under the other the stress of Cd, the tolerance index of Xiangzhu III" was greater than "Fushun qingma". Except the stress of concentration of Cd 22mg/L, the enrichment index of "Fushun qingma" was less than "Xiangzhu III"; under the other stresses of Cd, the enrichment index of "Fushun qingma" was greater than "Xiangzhu III".No matter under the condition of soil culture or under hydroponic conditions, the tolerance index of Xiangzhu III" was greater than "Fushun qingma". Under the stress of low concentration of Cd (125 mg/L), the enrichment index of Xiangzhu III" was greater than "Fushun qingma", but when the the stress of concentration of Cd achieved the specific concentration; the enrichment index of "Fushun qingma" was greater than "Xiangzhu III" Under the condition of soil culture or under hydroponic conditions, this result was the same, which proved to identify the cadmium tolerance and enrichment of ramie varieties under hydroponic conditions was feasible.The content of anthocyanin in ramie varies with the stress level and ramie varieties. With the increase of concentration of Cd stress, anthocyanin response mode in ramie can be divided into two categories:① Under Cd stress, the change of anthocyanin content was first increased and then decreased, but the change amplitude was not significantly, it includes"Fushun qingma", "Xiangzhu III", "Zhongzhu I"② Under Cd stress, the change of anthocyanin content was first increased and then decreased, but the change amplitude was very significantly, it includes"Red ramie I"and"Red ramie II", "Dahongpi II" and "Hongxuan I". |
PDF Full Text Request