Establishment Of Callus Regeneration System Of Millet Seeds And Preliminary Study On Physiological Mechanism Of Herbicide Resistant

In this experiment,the seeds of different varieties of mature millet were used as explants.The effects of different plant hormone types and concentration ratios on callus induction and plant regeneration of mature millet seeds were studied in order to establish a stable and efficient millet seed regeneration system.The further application of engineering technology in the millet and the development of the related breeding of millet.At the same time,two kinds of millet seeds,Jingu 21 and Zhangzagu 10,were used as materials to study the effects of different concentrations of sethoxydim on the seed germination,the callus induction and the physiological indexes of SOD,POD,MDA and CAT activities.The physiological mechanism of herbicide resistance to millet seed callus was preliminarily studied,which laid a foundation for further in vitro screening of herbicide resistant mutants and breeding of millet herbicide resistant varieties.The specific research results are as follows:1.The mature seeds of Jingu 21 were used as explants to induce the production and differentiation of embryogenic callus.The results showed that the induction of callus was better than the addition of 2,4-D in MS medium,and the addition of a suitable concentration of 6-BA could improve the quality of callus in MS medium.When 2,4-D 2.0 mg/L and 6-BA 0.2 mg/L were added,the callus induction rate was the highest,which was 92.86%.The effect of 6-BA induction of callus differentiation was better than ZT,and it was added to the medium.NAA can increase the rate of callus differentiation.When 6-BA 1.0 mg/L and NAA 0.5 mg/L were added,the callus differentiation rate reached the highest at 25.00%.The millet-differentiated seedlings were transferred to 1/2MS medium.Differentiation of the roots of the seedlings is longer and stronger,and the differentiated seedlings grow well and can be used for transplanting.The optimal medium for inducing callus was MS+2.0mg/L 2,4-D+0.2mg/L 6-BA.The best medium for callus differentiation was MS+1.0mg/L 6-BA+0.5mg/L NAA.2.The mature seeds of 6 millet varieties of Jingu 29,Jingu 61,Zhangzagu 10,Zhangzagu 16,Jigu 39,and Jigu 41 were used as explants to study their induction.The situation in which embryogenic callus is produced and differentiated.The results showed that the establishment of in vitro regeneration system of millet seeds was significantly different among different varieties.The seed germination rate,callus induction rate and callus differentiation rate of different varieties were significantly different.The best screening medium for the induction of callus was: Jingu 29,Jingu 61,Jigu 39,and Jigu 41 were all MS+2.0mg/L2,4-D+0.2 mg/L 6-BA,Zhangzagu 10 and Zhangzagu 16 are MS+1.0mg/L 2,4-D+0.2mg/L 6-BA;the best medium for callus differentiation is: Jingu 29 5 varieties of Jingu 61,Zhangzagu 10,Zhangzagu 16 and Jigu 41 are MS+1.0mg/L 6-BA+0.5 mg/L NAA,and Jigu 39 is MS+2.0 Mg/L 6-BA + 0.5 mg/L NAA.The 6 kinds of millet differentiated seedlings can root on 1/2MS medium,and the roots of the differentiated seedlings are long and strong,and the differentiated seedlings grow well and can be used for transplanting.3.The effects of different concentrations of sethoxydim on seed germination,callus induction and physiological changes were studied by using two types of millet,Jingu 21(no sethoxydim resistance)and Zhangzagu 10(Have sethoxydim resistance).The results showed that increasing the sethoxydim concentration of additional capture in the medium had a significant effect on the germination rate and callus induction rate of millet seeds,and the effect on Jingu 21 was greater than that of Zhangzagu 10.Under the different concentrations of sethoxydim concentration,the contents of SOD,POD,CAT,soluble protein and Pro in Jingu 21 increased first and then decreased.MDA content,cell membrane permeability and O2-content decreased first.The trend of increasing;while the SOD and POD in Zhangzagu 10 showed a trend of increasing,CAT and O2-content both increased first and then decreased,MDA content decreased first and then increased,cell membrane relative permeability,solubility Protein content and Pro content are constantly changing.The results showed that the resistance of the millet callus to herbicides was related to the activity of various protective enzymes and the content of intracellular osmotic adjustment substances.Millet callus can increase the resistance to herbicides by increasing the activity of protective enzymes(SOD,POD,etc.)and regulating the content of osmotic adjustment substances(soluble proteins,etc.).