Effects On Grafting On Fruit And Correlated Agronomic Characters Of Xianlajiao Chili Pepper

The grafting effect of Xianlajiao Chilli pepper was mainly reflected in two aspects:plant growth and development and fruit quality of its.In order to understand and compare the effect of different rootstocks on the growth and development of plantsand quality of fruits in Xianlajiao chili pepper.The grafting experiment was carried out.Two varieties of Xianlajiao chili pepper,Xinxiang No.8 and Duojiao as scion,were grafted onto 4 semi-wild varieties of wild pepper,including Yelimu,Gelafute,Buyeding and Fugenweishi.The seedlings of Xinxiang No.8 and Duojiao were used as CK1 and CK2,and the split grafting method was used in this research.The growth and development of plant were studied from these aspects of plant growth,photosynthetic characteristics,root characteristics and so on,and the quality of fruit was studied from thees aspects of fruit appearance and yield,soluble sugar,soluble protein,vitamin C,proline,capsaicin,dihydrocapsaicin and other nutrients.It is expected to screen appropriate rootstocks for common cultivated varieties of Xianlajiao chili pepper in Guanzhong area of Shaanxi Province,and provide the theoretical basis for optimizing planting situation,improving fruit quality and yield,and breeding new varieties.The results show that:1.In terms of survival rate,the grafting survival rate of the two tested varieties was the highest in Yelimu,followed by Gelafute,Buyeding,and the lowest was Fugenweishi.2.In terms of growth,the rootstocks of Yelimu,Gelafute and Buyeding could promote the plant height and stem diameter of the two kinds of Xianlajiao chilli pepper,and the grafting had more significant effect on the plant height.Compared with the control,the initial flower node of Xinxiang No.8 grafting treatmentsdecreased by one to two nodes,Duojiao was down by three to four nodes.Between two tested Xianlajiao chilli peppers,Duojiao had a relative significant difference.Leaf area and plant size were less affected by grafting.3.In terms of photosynthetic characteristics,grafting promoted the formation of chlorophyll in Xianlajiao chilli pepper to a certain extent.After grafting,the net photosynthetic rate of Xinxiang No.8 was improved,stomatal conductanceand transpiration rate also changed with the same trend,and the intercellular CO₂concentration decreased.Except for Fugenweishi,the treatments of Duojiao showed the same change.4.Compared with ungrafted pepper,the growth of root in grafted pepper was slower.At the late stage of growth,the fresh and dry weight of Yelimu,Gelafute,Buyeding as scion was higher than that of the control,espegially Yelimu significantly promoted the growth of root dry and fresh weight in Xianlajiao chilli.The change of root length and root volume was similar to that of root fresh and dry weight.The number of root tips,branches and cross were lower than that of the control in the early stage,then continuously increase to higher than control with the growth and development of Xianlajiao chilli pepper.5.In terms of fruit shape,two varieties of Xianlajiao pepper was grafted onto Yelimu,Gelafute,Buyeding,the fruits showed growing trend,the fruit length and fruit diameter increased,the fruit shape index were different because of different rootstocks and scions,and so does pulp thickness and fetal width.The effect of Xinxiang No.8/Buyeding on fruit was the most obvious,and the effect of Duojiao and Yelimu on the fruit was the most obvious.6.In terms of nutritional quality,Yelimu,Gelafute,Buyeding as rootstocks promoted the synthesis of dry matter and soluble sugar in Xianlajiao chilli pepper.The content of fruit soluble protein increased in two tested Xianlajiao chilli pepper with Gelafute as rootstock.Yelimu as rootstock significantly promote the increase of soluble protein in two tested Xianlajiao chilli pepper,and vitamin C slightly increased.7.In terms of capsaicin content,in the four tested rootstocks,the content of capsaicin showed increasing trend when two tested varieties Xianlajiao chilli pepperwas grafted onto Yelimu,but the trend not reach a significant level.Capsaicin content in the other grafting treatments decreased,and decreased to a significant level in two varieties Xianlajiao chilli pepperwith Gelafute and Buyeding as rootstocks.8.In terms of fruit yield,Yelimu,Gelafute and Buyeding all promoted the increase of fruit yield of Xianlajiao chilli pepper.Among them,Xinxiang No.8 grafted onto Gelafute had a remarkable effect on yield increase,and Duojiao graftedonto Yelimu,Gelafute had a better yield but did not reach a significant level.