CALLUS INDUCTION AND ROOT DIFFERENTIATION FROM ALTENANTHERA PHILOXEROIDES

With the development of modern industry and agriculture, a major problem faced by the modern world:environmental pollution. The lack of affordable,effective approaches to environmental remediation has created a major need for development of novel approaches. Plant have many endogenous genetic, biochemical,and physiological properties that make them ideal agents for soil and water remediation. Significant progress has been made in recent years in developing native or genetically modified plants for the remediation of environment contaminants. Improvement of plants by genetic engineering open up new possibilities for phytoremediation. Tissue culture is prerequisite to plant genetic engineering. Alternanthera philoxeroides may be useful in remediation of environmental pollutants by transgenic engineering. But there is no report on tissue culture of Alternanthera philoxeroides. Alternanthera philoxeroides is dicotyledon. It was collected from the suburb of YangZhou in JiangSu Province. In this paper, it were studied that effect of NaClO、AgNO3 and HgCl2 solution to sterilization of A. philoxeroides. Contamination rate were from 40% to 50% and germination rate were below 10% after stems with axillary bud of A. philoxeroides. were sterilized with 20% NaClO solution for 10—20 minutes. It was applicable to stems with axillary bud of A. philoxeroides to sterile with 1% AgNO3 solution for 20—25 minutes. contamination rate of A. philoxeroides were from 11.1% to 0 and germination rate were from 55 6% to 50% or to sterile with 0.1% HgCl2 solution for 3—5 minutes, contamination rate were from 25% to 0 and germination rate were from 58.3% to 44.4%.The results showed that the necessary time for killing bacteria contaminated in the tested material with 1% AgNO3 was 20—25 minutes of with 0.1% HgCl2 was 3—5 minutes. This study examined the effects of explants、media and exogenous phytohormone on tissue culture of Alternanthera philoxeroides . The stems,leaves and roots were used as the explants to study tissue cultue. Different basic mediaMS、1/2MS、 MS(1/2)、B5,0—0.5mg/L of indoleacetic acid(LAA),0—0.2mg/L of naphthyl acetic acid(NAA),0.5—5.0mg/L of 6-benzylaminopurine(6-BA) and 0.5—4.0mg/L of Zeatin (ZT)as additional compositions were used for inducing, differentiating and rooting tests.Induced results showed that 1/2 MS was more suitable for calli to grow and divide than B5、MS(1/2)and MS. The stem and leaf of Alternanthera philoxeroides were suitable organs for tissue culture. Stem>leaf was observed on growth rate. The combinations of NAA and BA or IAA and ZT can induce calli of the stem and leaf of Alternanthera philoxeroides, and the rate of calli induction increases with the increase of BA concentration. The higher rate of NAA/BA,the more roots from the calli format. It was thought that the results of this study could provide an useful basis for genetic transformation of Alternanthera philoxeroides.