Study On Changes Of Physiology And Biochemistry During Its Leafcolour Transformation Of Photinia×Frasery 'Red Robin'

Changes of leaf pigment content,soluble sugar content,enzyme(PAL,SOD,POD) activity and photosynthesis characters in leaf of Photinia×frasery'Red Robin'were searched of five different shading treatments(100%,80%,50%,25%,10%transmission rate).The seasonal variation of leaf color and stability of anthocyanin were studied in this paper.Purpose of the research is to master the Physiological characters during leaf color transformation of Photinia×frasery'Red Robin',and provide evidences to promote introduction cultivation and the application under different garden environment of them.The main findings are summarized as follows.1.The contents of chl a,chl b,chl a+b and carbohydrate was increasing gradually with transmission rate lower,the max content of chlorophyll were under 25%and 10% transmission rate,the chang range was the largest,and the min at 100%;The change tendency of the anthocyanin and chlorophyll was opposite.The content of anthocyanin under 25%and 10%transmission rate significant lower than other transmission rate(P＜0.05),and the chang range was the lowest.Correlate analysis also show that there were highly significant positive correlation among the photosynthetic pigment,but highly significant negative correlation with anthocyanin.2.The PAL activity under full light was significant higher than other transmission rate(P＜0.05),the minimum activity of PAL was under 25%and 10%transmission rate,and the chang range was the lowest.The PAL activity was highly significant positive correlation with anthocyanin,but highly significant negative correlation with photosynthetic pigment.3.The soluble sugar content under 80%transmission rate significant higher than other transmission rate(P＜0.05),and under 25%transmission rate it significant lower than other transmission rate(P＜0.05).Correlate analysis show that there were significant negative correlation between soluble sugar and photosynthetic pigment,but significant positive correlation with anthocyanin.4.The SOD activity under full light were significant higher than other shading treatment(P＜0.05),and they were all degreased with transmission rate lower;The POD activity under 80%and 50%transmission rate was significant higher than full lignt(P＜0.05),the lowest activity of SOD and POD all presented under 10%transmission rate.Correlate analysis show that photosynthetic pigment was highly significant negative correlation with SOD activity,but there was no significant correlation with POD activity; The anthocyanin was highly significant positive correlation with SOD activity,but highly significant negative correlation with POD activity.5.The light compensate and saturated points were 29μmol/(m~2·s)and 1250μmol/(m~2·s) respectively,it liked light very much and was beneficial to express the leaf color when it was planted in light-enough place.The curves diurnal variation of net photosynthetic rate of Photinia×frasery'Red Robin'with 100%and 80%transmission rate presented two peaks,and appeared remarkable "noon-drop'phenomenon,high point appeard about 10:00 AM,about 16:00 appeard secondary peak in the afternoon;The curves diurnal variation of net photosynthetic with 50%,25%,10%transmission rate presented single peak,and the peak occurred about 10:00 AM.The max net photosynthetic rate and average net photosynthetic rate presented at 80%transmission rate,but the minimum presented at 10%transmission rate.6.The seasonal variation of the content of chlorophyll and carbohydrate in Photinia×frasery'Red Robin'leaves was consistent,showed decrease-increase-decrease curve,the max presented on July and August respectively.The seasonal variation of the content of anthocyanin and the PAL activity in Photinia×frasery'Red Robin'leaves was consistent,showed increase-decrease-increase-decrease curve,the max presented on June and October,the min presented on November.The seasonal variation of the content of soluble sugar leaves showed decrease-increase-decrease curve,the max presented on October,the min presented on June and November.7.The anthocyanins investigation into stability indicated that,sun shining can speed up the pigment degeneration,but roomlight has littlr effect on it;Low temperature can slow down the pigment degeneration,and is beneficial to anthocyanin preservation;The anthocyanin is stable in low pH,and has hyperchromic effect,high pH can speed up it fading and discoloration.Through different comparison the optimum extraction conditions of crude anthocyanins from the materials showed that,1.0%HCL-MOH was the best extractant,and expiration was relatively pure and highly concentrated.