Studies On In Vitro Selection For Fusarium Toxin-resistant Variant Cell Lines And Analysis Of The Resistance To Scab Of Regenerated Plants

Wheat scab is a main effect on wheat production. Larger quantity of toxin produced by Fusarium head blight accumulated in grains may endanger seriously to the health of man and animals. It is more and more concerned by world wild breeders to breed new varieties of wheat with greater tolerance to Fusarium graminearum. It is one of the main breeding targets to improve the wheat scab-resistance. The technique of in vitro selection for toxin-resistant variant cell lines has provided a new way to create and choice multi-gene resistant materials.Effect of sucrose and plant hormone on the formation and growth of immature infloresences someclone in wheat were studied by using induction medium containing sucrose and plant hormone. The result showed that the 2, 4-D promoted the formation and growth of the wheat immature infloresences someclone in the higher concentration but it promoted the formation of the wheat immature infloresences regenerated someclone in the lower concentration. In the lower concentration, the KT promoted the formation and growth of wheat immature infloresences regenerated someclone significantly higher than that of it in the higher concentration. The sucrose promoted the formation of wheat immature infloresences regenerated someclone significantly. Meanwhile, a good regenerated someclone of wheat has been established by the combination of lower concentration KT with 2,4-D and sucrose.Some toxin-resistant variant cell lines have been acquired from Xiaoyan22 and Qianjinzao with many good characters by one-step or by many-step selection procedure, from immature embryoes or from callus, or by the combination of all above the methods. Compared and analysed the efficiences of different selection methods in different concentrations of toxin, and studied the resistance to scab and agronomic traits of regenerated plants Rl and R2 of toxin-resistant variant cell lines. Confimed that it is an efficient way to improve wheat resistance to scab by cell engineering, in which way regenerated plants with higher resistance to Fusarium graminearum and better agronomic traits can be acquired. Selection from immature embryoes and by multi-step in higher concentration of toxin can gain more scab-resistant regenerated plants and higher resistance to scab than from callus and in lower concentration of toxin. And the agronomic traits of the scab-resistant regenerated plants can take changes too, especially the high of the stems and the character of the infloresences .Meanwhile, the resistance to scab of regenerated plants could be passed to next generation from Rl.