Study On Tissue Culture And Artificial Seeds Of Sweet Potato

Sweet potato is the crop that reproduce generation through it's root, so the study of artificial seeds of sweet potato is more important than the other crops'. Now the frequency of somatic embryogenesis of the most sweet potato species is low. Which restrict the development of sweet potato artificial seeds. The test has studied the somatic embryo induction and plant regeneration of "138" and "yiwohong".l.The induction and growth of callus Culture stems of the tow species on MS media added sucrose , agar, pH value in different consistency. The result show that media containing 25g/L sucrose, 0.8% agar, pH5~6 is good for callus to grow. Culture leaves, stems, petiols of "138" and "yiwohong" on MS media supplemented different plant growth regulator. Calli' productions and qualities are very different. Calli induced from three types of explants on MS media added Img/L 2,4-D and KT are light yellow, crisp. But 2,4-d in high consistency is not good for callus growth. Added NAA instead of 2,4-D, the callus is hard and light green, "yiwohong" is better than "138" in growth vigor. Among the three sorts of explants, the leaf is the easiest to be induced.2. Embryogenic callus and nonembryogenic callus Calli induced from different explants are divided into three types(type NE,E and G). NE callus is pale, soft and lose. It grows quickly. The shape of it's cells are irregular. Type E callus is slight yellow and crisp. It grows relatively slow. It's cell is small and round, and containing reach cell matri. Type G callus is smooth and hard. Img/L 2,4-D is good for induction of type E callus. Continue culture can rise the rate of type callus.3.Organ differentiation Culture calli induced from different explants to differentiate organ. Root differentiation is easier than bud's. It's differentiation rate can arrive to 100%. Bud's highest differentiation rate is 33.3%. Among the three sorts of explants, stem and leaf are easier than petiol in differentiation.4.Cell suspension culture Having cultured the embryogenic callus of "yiwohong" in liquid MS with 0,0.5,l,2,4mg/L 2,4-D, It show that the liquid media with no 2,4-D is good for somatic embryogenesis.5.Studies on artificial seeds of sweet potato Stems with auxiliary buds in different length are encapsulated with 4-6% sodium alginate and 2% calcium chloride to make artificial seeds. Artificial seeds are put into different germination matter to test it's ability of germination. The germination rate is positive correlate with the length of auxiliary bud. The desirable consistency of sodium alginate is 4%. Addition of MS and 0.1% carbendazin can rise the germination rate of artificial seeds.