To study the feature of apoptosis and the change of its ratio induced by HMC toxin in the root cap cells detached from two pair of homokaryon C and N inbred line of maize. Acridine orange( AO) and ethidium bromide( EB) staining methods were used to detach the apoptosis of root cap cells. In the process of induction,root cap cells appeared apoptotic bodies and marginate of chromosome morphology. Living,necrosis and apoptosis cells could be distinguished clearly by AO and EB complex staining. The result showed that the ratio of apoptosis in C cells was sharply higher than thatof N,and the max ratios of apoptosis of B37-C and B37-N stained by AO and EB were 45. 3% and15. 3%,respectively. In contrast,the max ratios of apoptosis of Mo17-C and Mo17-N stained by AO and EB were 63. 7% and 6. 39%,respectively. It is concluded that harmed by HMC toxin,the root cap cells appear apoptosis. The ratio of apoptosis in C cytoplasm was higher than in N cytoplasm. Along with the increase of toxin concentration and treating time,the ratio of apoptosis became higher.HMC toxin induced root cap cells apoptosis,cell nucleus issued a green fluorescent,necrotic nuclei are orange red fluorescence,and loose granular cell nucleus or crescent,apoptotic cells emit yellow or green fluorescence,chromosome becomes pyknotic crescent or granule shape.

AO and EB fluorescent double staining and Hoechst 33258 fluorescent staining methods were used to detach the apoptosis of root cap cells.Detection of apoptosis and the change of its ratio induced by HMC toxin in the root cap cells detached from a pair of homokaryon B37-C and B37-N inbred line of maize.In contrast,the ratios of apoptosis of B37-C were 24.8%,58.2%,70.2%,and B37-N were 11.0%,25.7%,36.6% by AO and EB staining,after HMC-toxin with 50,100,150 μg/mL treated for 7h.The max ratios of apoptosis of B37-C and B37-N stained by AO and EB were 62.3% and 25.8%,respectively,after HMC toxin with 150 μg/mL treated for 4 h.And the ratios of apoptosis of B37-C were 32.5%,58.7%,74.5% and B37-N were 7.5%,22.3%,30.7% by Hoechst 33258 staining, after HMC-toxin with 50,100,150 μg/mL treated for 7 h.The max ratios of apoptosis of B37-C and B37-N stained by Hoechst 33258 were 62.3% and 19.3%,respectively,after HMC toxin with 150 μg/mL treated for 4 h.

Apoptosis in leaves and protoplasts from homokaryon maize Mo17-C and Mo17-N treated by Hel-minthosporium maydis race C ( HMC) toxin were detected by DNA ladder and hoechest 33258 respectively. The DNA ladder result indicates that DNA ladder appeared in both Mo17-C and Mo17-N, and the obvious DNA lad-der in Mo17-C appeared after 12 h induction when the concentration of HMC reached 250 μg/mL, but appeared in Mo17-N when the concentration reached 300 μg/mL. Protoplasts of both Mo17-C and Mo17-N revealed apop-totic features such as apoptotic bodies, ring chromatin or chromatin margination. The apoptosis rate of Mo17-C maize protoplasts were significantly higher than that of Mo17-N in the same treatment, and it increased with the increase of treatment time and concentration. So, it is concluded that Mo17-C was more sensitive than Mo17-N.

The toxin activity of Helminthosporium maydis race C( HMC) was detected by 3 different methods,and their detection effects were compared. The results showed that isolated leaf acupuncture inoculation could be relatively simple to detect the activity of toxins and lesion formation,but was not carried out for qualitative analysis. The method of root cap cells staining could be used for qualitative as well as qualitative analysis. Although free protoplasts staining method for the determination of HMC toxin activity was accurate and reliable,it cost a lot. In contrast,the method of root cap cell staining is a simple,quick,accurate,economical and applicable method for the determination of disease resistance and can quickly screen the resistant individuals,which provide a material basis for accelerating breeding.

Apoptosis in protoplasts from homokaryon maize B37(CB37,NB37) and Mo17(CMo17,NMo17) inbred lines treated by HMC-toxin were studied.Homokaryon maize B37 and Mo17 inbred lines were tested and the protoplasts may be stained by AO and EB.The protoplasts were divided into 4 groups.3 groups were treated by 0,50,100,150 μg/mL of HMC-toxin as the experimental groups,and the induced time were 1,3,6 h to study the feature of apoptotic and the rate of apoptosis.The apoptotic features such as apoptotic bodies,chromatin margination or ring chromatin were found after the treatment.When treated by HMC-toxin with different concentrations,the apoptosis rates of CB37,NB37,CMo17 and NMo17 maize protoplasts were 10.80%,4.90%,21.00%,and 8.83%.According to the above study,a conclusion can be reached as follows: apoptosis in protoplasts from homokaryon maize B37 were the same as that of Mo17;CB37 and CMo17 were more sensitive to HMC-toxin than NB37 and NMo17,respectively;when treated by the same concentration of HMC-toxin,the apoptosis rates of CB37 and CMo17 maize protoplasts were significantly higher than NB37 and NMo17 respectively;the rates of apoptosis were significantly different between C and N,and the former was significantly higher than the latter.In addition,the apoptosis rate increased when the treatment time and the concentration increased.

The sedimentary veins of Tamarix cone is a new method to recovery the ancient environment.On the basis of the positive ion content and the relationship between the content of K+,Na+,Ca2+ and Mg2+ in the layers of the fallen leaves in sedimentary veins of Tamarix cone and environmental change in Lop Nur region,the researched result has been obtained as follows: the average positive ion contents of K+,Na+,Ca2+,and Mg2+ are 3.70 mg/g,40.33 mg/g,13.67 mg/g and 8.08 mg/g respectively,the order of their change range is Ca2+K+Mg2+Na+;The inter-annual changes of the four kinds of metal element content are more obvious,and the variation trend is more consistent,the correlations between each metal element contents are positive correlations with correlation coefficient of 0.653 0-0.813 8;The correlation coefficients between the total positive ion content and the each one are 0.814 4-0.959 9,the correlation coefficient between Na+ content and the total positive ion content is the highest,which indicating that Na+ content or the total positive ion content can reflect the change trends;there are better positive correlation between the content of positive ion and air temperature,and an inverse correlation between the content of positive ion content and annual precipitation and lake water surface area;with the underground water level has been downing,the water quality of underground water has become worse,and the quality of soil water has become worse,the content of positive ion has increased;conversely with the underground water level has been going up,the water quality of underground water has become better,and the quality of soil water has become worse,the content of positive ion has decreased.The change of positive ion content in organic materials of Tamarix fallen leaves has verified the reliability of the dating of sedimentary veins of Tamarix cone,and the feasibility of using sedimentary veins of Tamarix cone to reveal the environmental change in Lop Nur region.

【Objective】 To study the feature of apoptosis and the change of its ratio induced by HMC toxin in the root cap cells detached from a pair of homokaryon Mo17-C and Mo17-N inbred line of maize.【Method】AO and EB staining and Hoechst 33258 staining methods were used to detach the apoptosis of root cap cells.In the process of induction,root cap cells appeared apoptotic bodies and marginate of chromosome morphology.Living,necrosis and apoptosis cells could be distinguished clearly by AO and EB complex staining and Hoechst 33258 staining.【Result】The ratio of apoptosis in Mo17-C cells was sharply higher than that of Mo17-N,and the max ratios of apoptosis of Mo17-C and Mo17-N were 68.7% and 29%.In contrast,the max ratios of apoptosis of Mo17-C and Mo17-N stained by Hoechst 33258 were 57.3% and 27.7%,respectively.After HMC toxin with 150 μg?mL-1 treated for 7 h,the apoptosis rate was the highest.【Conclusion】 Harmed by HMC toxin,the root cap cells appeared apoptosis.The ratio of apoptosis in C cytoplasm was higher than in N cytoplasm.Along with the increase of toxin concentration and treating time,the ratio of apoptosis became higher.In spite of the different staining methods by AO and EB or by Hoechst 33258,the ratio of the cell apoptosis was similar.But the early and late apoptotic cells could be distinguished only by AO and EB complex staining.

Apoptosis in protoplasts and leaves from Homokaryon maize B37 treated by HMC toxin were studied.The apoptotic features such as apoptotic bodies,chromatin margination or ring chromatin were found after the treatment stained by Hoechst33258.When treated by the same concentration of HMC toxin,the apoptosis rate of B37-C maize protoplasts were significantly higher than B37-N.In addition,the apoptosis rate was increased when the treatment time and concentration increasing.For the leaves of maize B37-C,the obvious DNA ladder was appeared with treatment concentration:200 μg/mL;treatment time:6 h.For the leaves of maize B37-N,the obvious DNA ladder was appeared with treatment concentration:200 μg/mL;treatment time:9 h which was longer than leaves of maize B37-C.Apoptosis in protoplasts from Homokaryon maize B37 were same to the leaves.B37-C was more sensitive than B37-N.

The root cap cells of CB37 and NB37 were divided into 4 groups,in which 3 groups were induced by 50 μg/mL,100 μg/mL,150 μg/mL of Helminthosporium maydis C toxin(HMC-toxin) as the experimental group,and one group induced by pH 6.5 PBS as the control group.The inducing time was 1 h,4 h and 7 h.The apoptosis of root cap cell was examined with 3 methods:neutral red and Evans blue staining,AO and EB staining and Hoechst 33258 staining.In the process of induction with HMC toxin,apoptotic bodies appeared in root cap cells and the chromosome morphology became marginate.Living and death cells could be clearly detected after Neutral red and Evans blue staining and the ratio of death in CB37 cells treated with 150 μg/mL HMC-toxin was higher than that of NB37 with the maximum death rates of 99.2% and 95.5%.Living,necrosis and apoptosis cells could be distinguished clearly by AO and EB complex staining and Hoechst 33258 staining.The ratio of apoptosis in cells of CB37 was much higher than that of NB37,the max ratio of apoptosis cells of CB37 and NB37 were 70.2% and 36.7%.In contrast,the max ratio of apoptosis cells of CB37 and NB37 were 74.5% and 30.7% stained by Hoechst 33258 respectively.The max ratio of apoptosis in CB37 and NB37 occurred in 150 μg/mL HMC-toxin treated for 7 h.Therefore,a conclusion can be made as follows:during the process of the harm by HMC-toxin,apoptosis appeared in the root cap cells,the ratio of apoptosis in C cytoplasm was higher than that in N cytoplasm.Along with the increase of the toxin concentration and treating time,the ratio of apoptosis became higher.In spite of the different staining methods by AO and EB or by Hoechst 33258,the ratio of the cell apoptosis was similar.But the early and late apoptotic cells can be distinguished only by AO and EB complex staining.

Apoptosis in detached corn root cap cells under fluorescent microscope was studied.A pair of homokaryon(CB37 and B37)inbred lines in maize was tested and the detached corn root cap cells might be using acridine orange staining.Apoptosis was found under fluorescence microscope treated by filtrated culture fluid of HMC toxin.The sensitivity of HMC toxin to C cytoplasm was greater than N cytoplasm,so that the quantity of the apoptosis was great more in the detached corn root cap cells with C cytoplasm than with N cytoplasm.Besides,apoptosis was not found in the CK.These indicated that special disease response occurred in the course of apoptosis in detached corn root cap cells of C cytoplasm maize led by HMC.

Seven rejuvenation mediums of HMC were used in this paper,and two superior mediums V8-Juice agar medium and corn seedlings-cooked agar medium were obtaind.The strain grew strongly in these two mediums.The mycelium was dense and thick,and the growth rate were 6.46 mm/d and 6.33 mm/d respectively.Sporulation quality were 2.72×106 A/mL and 1.92×106 A/mL respectively.The rejuvenated viral extraction had a specific effect of poisoning on C and N cytoplasm,whith reflected the strain on the rejuvenation had the high degree of effectiveness.