Research On The Photosynthetic Characteristics Of Cerasus Humilis Introduced In Chengdu

Cerasus humilis has highly valued and highly adaptable.Based on the local situation in Chengdu,from the Yuncheng city of Shanxi Province introduced the ‘Nongda number4’and the ‘Nongda number 5’excellent varieties,and conducted pilot experiments in Chengdu area.This experiment on the Cerasus humilis in the Chengdu area of phenology,winter,the summer,disease-resistant ability,observation statistics and analysis,the LI-6400 portable photosynthetic apparatus to determine the physiological and ecological indexes,studied the Cerasus humilis introduction to Chengdu region in different seasons of photosynthetic physiological characteristics and situation of seasonal change of chlorophyll content and so on,then make evaluation to introduction adaptability.Statistics and analysis of relevant data,the main results are as follows.(1)The phenology period of the two imported Cerasus humilis varieties in Chengdu area was earlier than that of the origin.Both varieties have budding in early March,and leaf in late March,flowering around March 20,fruit ripening in the middle and late July,and deciduous period from the end of October to the beginning of November.The flowering phenology of ‘Nongda number 4’and the‘Nongda number 5’was almost simultaneous.The leaf phase of the‘Nongda number’is a few days later than that of the ‘Nongda number5’;The fruiting phase of the ‘Nongda number 4’is earlier than that of the ‘Nongda number5’.(2)Compared with ‘Nongda number 4’,‘Nongda number 5’is slightly more ornamental.The ‘Nongda number 5’plant has a more compact shape,with a higer plant height,base diameter,flowers,and leaf leaf area than ‘Nongda number 4’.The leaves of‘Nongda number 5’are oblong,and ‘Nongda number 4’is long and narrow.The fruit shape index of ‘Nongda number 5’was 0.98,while that of ‘Nongda number 4’was 0.82,It can be seen that the of ‘Nongda number 5’was nearly spherical,while the fruit of ‘Nongda number4’ was oblong.(3)The introduced two Cerasus humilis varieties can safely pass winter and summer in Chengdu and have strong resistance to pests and diseases.(4)The photosynthetic of characteristics of different varieties t in the same month were differen,and the photosynthetic characteristics of the same variety in different months were different.In different months,the Pn of the‘Nongda number 5’has a double peak curve in different months,In May,the second peak was higher than the first peak.In July and September,the first peak was higher than the second peak.There were also differences in the photosynthetic characteristics of different varieties on the same day.And Pn of‘Nongda number 5’ is larger than ‘Nongda number 4’ on the same day.The change trends of Tr,Gs and Pn were similar,which was roughly opposite to that of Ci,indicating that the factors affecting photosynthetic rate were mainly stomatal factors.In May,WUE showed a single peak curve.In July and September,the WUE and net photosynthetic rate changed similarly and presented a double peak curve.(5)Difference in light response characteristic parameters of two Cerasus humilis varieties between different months.In September,AQY was higher than other months,indicating that the use of Cerasus humilis in September has the highest efficiency.In may,the efficiency of the light energy utilization was higher than that of the ‘Nongda number 4’,which was less than that of the ‘Nongda number 4’in July and September.The characteristic parameters of CO2 response were also different in different months.In July,CE was higher than other months,indicating higher photosynthetic rate at lower CO2 concentration in July.The‘Nongda number 5’is higher than the ‘Nongda number 4’,which indicates that the ‘Nongda number 5’has higher photosynthetic rate at lower CO2 concentration.(6)Changes in chlorophyll content were consistent with Pn in different months.In July,Chl(a+b)was higher than other months,and Chl(a/b)was smaller than other months,indicating that li had a strong utilization rate of light energy in July.The high content of Chl(a+b)and low Chl(a/b)in the‘Nongda number 5’show that the‘Nongda number 5’ is more efficient than the ‘Nongda number 4’.