| In this experiment,the waxy hulless barley variety Gan Ken 5 and the non-waxy hulless barley cultivar Beiqing 6 and Kunlun 12 were used as experimental materials.The two-wavelength spectrophotometric method was used to determine Ganken 5,Beiqing 6 and Kunlun 12.The dynamic changes of amylose and amylopectin content in grain filling stage of three highland barley varieties were studied by logistic analysis of starch accumulation in grain filling period,and the synthesis rate of total starch,amylose and amylopectin was obtained.The changes of key enzyme activities of starch metabolism were studied by measuring the enzyme activity.The regulation mechanism of the key genes of starch metabolism in transcription level was studied by real-time Polymerase Chain Reaction technique,and the relationship between them was analyzed.The results showed that:1.The content of amylopectin and the content of total starch in the three kinds of waxy hulless barley cultivars GanKen 5 and non-waxy hulless barley cultivars Beiqing 6 and Kunlun 12 increased gradually with the grain filling stage,and the content of amylose in Beiqing 6 and Kunlun 12 is also with the grain filling period and gradually increased.The accumulation rate of amylopectin in Beiqing 6 and Kunlun 12 was faster than that in the late stage,and the ratio of amylopectin and amylose gradually decreased,and it was about 15 days after anthesis.The ratio has no difference.The average rate of total starch,amylose and amylopectin increased gradually after 20 days after anthesis,and reached the peak at about 20 days after anthesis,and decreased gradually after 20 days.The maximum accumulation rates of the three highland barley varieties were about 21 days after anthesis,and the maximum accumulation rate and average accumulation rate during grain filling were determined by the final accumulation of amylose and amylopectin.2.The results showed that the activities of AGPP,SSS,GBSS and SBE were the highest in the process of grain fermentation during the grain filling process of beiqing 6 and Kunlun 12,and the results showed that the activities of starch synthase AGPP,SSS,GBSS and SBE were the single peak.The activity of AGPP in Kunlun 12 and the activity of GBSS in Beiqing 6 reached the peak at 25 days after anthesis,and the activities of AGPP,SSS and SBE in Ganken 5 and SSS,GBSS and SBE in Beiqing 6 and the AGPP,SSS and SBE in Kunlun 12 reached the peak at about 20 days after anthesis.In the process of grain filling,the ?-amylase showed the trend of rising-down-rising-down at about 10 days after anthesis,there is the first peak,and after the drop to the lowest about 20 days after anthesis,about 25 days after anthesis,once again peak,and then began to decline,and ?-amylase is basically the first decline after the trend,the minimum activity of the amount of ?-amylase reached the bottom at the 20 days after anthesis.3.The results of correlation analysis showed that amylopectin accumulation rate was significantly positively correlated with the activities of AGPP,SSS,GBSS and SBE in Beqing 6 during the grain filling stage.The rate of amylopectin and total starch accumulation was significantly or positively correlated with the activity AGPP,GBSS,SSS and SBE in Beiqing 6 and Kunlun 12.There was no significant positive correlation between the accumulation rate of amylopectin and total starch of Ganken 5 and the activities of AGPP and SSS during the grain filling stage.The accumulation rate of amylose,amylopectin and total starch was negatively correlated with the activity of ?-amylase in Beiqing 6 and Kunlun 12 during the grain filling stage.The accumulation rate of amylopectin and total starch in Ganken 5 was negatively correlated with ?-amylase during the grain filling stage.4.The key enzymes for controlling starch metabolism were AGPP,GBSS,SSS,SBE,?-amylase and ?-amylase: AGPP-L and AGPP-S genes were large subunits and small subunits in encoding AGPP;GBSSI and GBSSII were the coding genes of GBSS;SSSI,SSSII and SSSIII were the coding genes of SSS;SBEI,SBEIIa and SBEIIb were the coding genes of SBE;AMY1,AMY2,AMY3 and AMY4 were the5.coding genes of ?-amylase;BAM1,BAM2,BAM3,BAM4,BAM5,BAM6 and BAM7 were the coding gene of ?-amylase.Real-time Polymerase Chain Reaction method was used to study the real-time expression of starch metabolizing genes in different stages during grain filling stage.The results showed that the expression pattern of the three hulless barley Varieties was similar,which could be divided into two kinds of curve patterns.The results showed that the expression patterns of starch metabolizing enzyme genes in different stages during grain filling were observed by real-time Polymerase Chain Reaction method.low-high-low single-peak curves and high-low-high-low bimodal.GBSSI was expressed less in the waxy Ganken 5,but it showed a single peak curve in the non-waxy material Beqing 6 and Kunlun 12.SSSII remained stable during the whole grouting process.AGPP,GBSSI,SSSIII and SBEI were highly expressed in the synthesis of endosperm starch during the early stage of the synthesis of seed germination.The expression of AGPP,SSSIII and SBEI was high in the early stage of the synthesis of seed germination;GBSSII expression at late flowering stage,but in the whole grouting process are low expression.AMY1,AMY2 and AMY3 were all expressed in the early flowering stage,and the expression level of AMY4 mRNA was relatively low in the middle flowering stage,while the expression of AMY4 mRNA was higher than that of the three barley cultivars.Stable,flowering late expression gradually increased trend.The expression levels of BAM1 and BAM2 were higher in the early stage of flowering,while BAM6 and BAM7 had higher expression levels in the later stages of flowering.BAM4 and BAM5 were expressed in the whole filling process. |
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