Protoplast Culture And Somatic Variation Of Ginger (Zingiber Officinale Rosc.)

Ginger (Zingiber officinale Rose.) is a cultivar producing rhizomes of the family Zingiberaceae. It is mostly distributed in the Asian tropical and subtropics region. And South Africa, North America and Australia also plant gingers. Gingers are rich in volatile oils and widely used as a condiments, dyes, beverage, medicine and vegetable. Gingers annually propagate themselves by rhizomes with low proliferation rate. They are heavily attacked by soil-born pathogens. And the quality of rhizomes degenerates for the long-term agamic propagation. Gingers seldom flowers and have seeds, so it is difficult to cultivate new variety through crossbreeding. In this paper, in vitro tissue culture techniques were carried out including somatic and embyogenic callus induction, embryogenic susppension culture and protoplast culture.1 Somatic embryogenic calli of 4 ginger genotypes were produced. Somatic embryogenic callus was induced from ginger shoot tips on MS medium supplemented with 1.0 mg/ L 2,4-D and 0.2mg·L-1 KT. The callus (about 1.5cm in diameter) were transformed into the MS+ 0.2mg·L-12,4-D+5.0mg·L-1 BA +3%sucrose+0.7%agar, and shoots and roots were formed. And shoots developed into complete plantlets with rhizomes on solid MS medium supplemented with 3.0mg·L-1 BA and 0.1mg·L-1NAA and 6% sucrose. The effect of phytohormones on embryogenic callus formation and redifferenciation was discussed. The effect of sucrose on rhizome formation was researched.2 Somatic embryogenic suspension cultures of 4 ginger genotypes were established. From which, regenerated plantlets were obtained. The relationship between the dry weight (DW) of suspension cultures and pH changes in medium was also discussed. The effects of inoculation and AgNO3on the growth of embryogenic suspensions were also discussed. The optimum concentration of inoculation and level of AgNO3 were 1.0% and 6.0 mg · L-1, respectively.3 Protoplasts were isolated from embryogenic suspensions incubating in enzyme solution containing 4.0% cellulose Onozuka R10, 1.0% maceroyme R10,0.1%PectolyaseY-23,0.5% CaCl2, 0.1% MES and 11% mannitol. The enzyme mixture were kept in a stationary position for 6 h and shaken (60 rpm) for 6 h at 27℃:. The yield and viability were 6.27 × 106g-1 and 90.7%, respectively. Purifying protoplasts were cultured initially in shallow liquid layers.4 The chromosome numbers of embryogenic callus-derived plants, embyogenic suspension-derived plants and protoplast-derived plants were 22, equal to their parent plants. There were differences of morphological characters between in vitro plants and parent plants such as leaf thick, leaf color and leaf index. The RAPD analysis of regenerated plants indicated relatively somatic variation. The chromosome number determination and RAPD analysis of embyogenic callus and embryoenic suspension-derived and protoplast-derived callus showed greater somatic variation than those of regenerated plants. Somatic variation frequency of in vitro plants was increased with the increasing subculture time.