Studies On Dedifferentiation Of Mature Wheat Embryos And Plant Regeneation

Wheat is one of the most important food crops in China, using bio-technology andgenetic engineering methods for improvement of wheat has attracted great attention and it isbecoming one of the more effective assistance ways for developing new wheatvarieties.Currently, immature embryos as explants are targets in wheat transformation. butimmature embryos obtained subject to seasonal restrictions, and difficult to control theconsistency of the state of development, so that the genetic transformation of wheat work hardto expand the scale; whereas mature embryos have a lot of advantages, such as it has subjectto no-seasonal restrictions, developmental status agreement. However, there is the ability toinduce regeneration of mature embryos and tissue culture is low, it is difficult to meet in anefficient genetic transformation of wheat requirements. Therefore, to further improvement andthe establishment of a stable and efficient genetic transformation system of the mature embryohas important practical significance.2excellent winter wheat (Xinong979and Zhoumai27) in south of Huanghuai wheatplanting area were used as materials in this study. One objective of our study is to optimizeand establish highly efficient regeneration system of mature embryos. In this paper, matureembryos of two wheat varieties as explants were in vitro cultured in different embryo-isolatedmethods, different concentrations of2,4-D of induction medium,2mg·L–12,4-D and differentKT concentration of differentiation medium. Through joins certain density of PEG6000andNaCl in the culture medium, the man-power simulates the outside drought and salt osmoticstress condition, carrying on processing to two wheat varieties. The results show that there arethe highest plant regeneration frequency and the lowest direct seedling/root frequency usingembryo survival method; when2,4-D concentration is2mg·L–1in the induction medium, thecallus induction frequency is highest in both of varieties. There is the highest plantregeneration frequency under MS+2mg·L–12,4-D+2mg·L–1KT of differentiation medium.Root length and survive efficient of regenerated seedlings were much better on1/2MSculture medium without auxin.Under the condition of osmotic stress, two kind of genetypewheat variety displays difference on drought-resistance and anti-salty, and appropriate hormone which has a proper density has a promoter function to growth of the wheat.