Studies On Factors Influencing Embryogenesis Of Isolated Microspores Of Xinjiang Turnips

The Turnip(Brassica rapa L.),(2n = 20), contains the AA genome it’s most difficult of brassica species in vitro regeneration, under the condition of in vitro microspore development with asynchronism and several development paths, and regeneration difficulty roots crops,particularly difficult isolated microspore culture in vitro regeneration. five kinds of Xinjiang turnip peculiar strain are used for experiment material, to explore the relationship between flower organ morphology and the development period of microspore; and to study the adding phytohormone high temperature pretreatment and low temperature pretreatment on the influence of the microspore embryoid occurred. The results are as follows:(1) Pollen microspore development has a direct influence on frequency embryoid, selecting the optimum development period, namely the mononuclear pollen material pull over period of pollen isolated microspore culture is one of the key factors of success.the suitable bud morphological index reference standards of Xinjiang turnip pollen microspore culture: the appropriate diameter of buds range from 1.9366 to 2.1537 mm and the bud aspect ratio range from 1.4194 to 1.646 mm, the petal length range from 1.3536 to 1.9323 mm, the ratio of flower length and anther length range from 1.2713 to-1.8923.(2) Genotype is the main factors which determine the happening of microspore embryoid.different xinjiang turnips genotype significant differences in the cultivation of microspore embryoid and three materials obtain embryoid.(3) After relatively high temperature pretreatment, the beneficial high temperature pretreatment temperature is 33 ℃,the beneficial time is 24 h.(4) After relatively low temperature gradient test, the beneficial low temperature time of Xinjiang turnip microspore culture for helping microspore induce embryo is 24 h.(5) Adding phytohormone ZT and NAA in the medium can improve the embryoid induction frequency. Adding phytohormone or not and the variety and proportion of phytohormone have different effect for different test materials.comprehensive comparison for xinjiang turnips ratio of isolated microspore culture of exogenous hormone concentration is 0.05 mg/ L ZT + 0.1 mg/ L NAA.