The Comparative Study Of Adaptive Character Of "Liangyoupeijiu" And Its Parents Under Chilling Temperature And Strong Light Stress Conditions

The paper included two parts.In the first part, ,the chlorophyll fluorescence parameters , memberance lipid perxiodation and the key indexs of active oxygen metabolism were measured using the seeding leaves of "liangyoupeijiu" and its parents as materials under chilling temperature and strong light stress conditions.Results shows that both the decrement of contents of chiorophyll and protein were all in the middle of his parents.Liangyoupeijiu have some marked heterbeltiosis in net photosynthetic,PSâ…¡primary photochemical efficiency(Fv/Fm) and photochemical quenching coefficient(qP).The activity of antioxidase and the active oxygen O2â”°,MDA,H2O2 accumulated are very complicated:The content of MDA are higher,but the contents of O2â”°and H2O2 were in the middle of his parents;The activity of POD are higher,but the activities of SOD and CAT were in the middle of his parents. It was demonstrated that chilling temperature photoocidation in "liangyoupejiu" was not better than its parents. In the second part,the full expanding flag leaves(the forth leaves)were studied.Based on the data collected from the super-hibrid rice "liangyoupeijiu" and its female parent Pei'64S and its male parent Indica rice 9311,their chlorophyll fluorescence parameters,memberance lipid perxiodation and the key indexs of active oxygen metabolism were measured under chilling temperature and strong light stress conditions.Meanwhile the D1 protein contents and xanthopyll cycle contents were studied as well.The results are stated as follows.Having the second a chlorophyll for miscellaneously handing over paddy rice "liangyoupejiu"with its close origin comparing, both the decrement of contents of chiorophyll and protein and PSâ…¡ primary photochemical efficiency(Fv/Fm)as well as photochemical quenching coefficient(qP) and the increment of non-photochemical quenching coefficient(qN) in "liangyoupejiu" were very small.These suggest that most light energy absorbed by super-hibrid rice "liangyoupejiu"was converted into chemical energy and little was dissipated in the form of thermal energy.Under chilling temperature and strong light stress conditions,the active oxygen O2â”°,MDA,H2O2 accumulated little in "liangyoupejiu",meanwhile it had a positive inductive acivation of scavenging active oxygen enzymens,such as SOD,POD,CAT,which in turn helped to clear up endogenous active oxygen could be scanveged efficiently and thus limited the membrance-lipid preoxidation,compared with its parents.As a result,it was demonstrated that "liangyoupejiu"had outgrown its parentsin photosynthetic physiology and possessed the advantage of tolerance for chilling temperature photooxidation.D1 protein contents of PSâ…¡ in photosynthetic apparatus droped small in "liangyoupejiu",the generation of antheraxathin9(A) and zeaxanthin(Z) of xanthophylls cycle were inhibited partly small in "liangyoupejiu".As a result, it was demonstrated that chilling temperature photoocidation in "liangyoupejiu" was lighter than its parents. As a conclusion,the high yielding of "liangyoupejiu"owed toa lot to its tolerance for photoinhibiton/photooxidation under chilling temperatureand high light stress conditions.This research provides essential physiological biochemical evidence for the selection and breeding of high yield rice...