Comprehensive evaluation of grafting compatibility of different stock-scion combinations in mango

【Objective】To determine the growth indicators of stock-scion combinations in mango grafted seedlings and physio-biochemical similarity between rootstocks and to screen stock-scion combinations with good early compatibility，so as to provide references for the rootstock selection of improved mango varieties.【Method】Five mango varieties，Jinghuang（J），Tiannong No.1（T），Kaite（K），Guifei（G）and Renong No.1（R）were used as scions and Zhihua No.3（Z）， Hongxiangya（X），Guangdongtumang（G），Hainantumang（H）and Yingzuimang（Y）were taken as rootstocks to make 25 stock-scion combinations. Some growth indexes of grafted seedlings and physio-biochemical similarity of rootstocks-scions were determined. And grafting compatibility of stock-scion combinations were evaluated through principal component analysis，membership function method and cluster analysis.【Result】ZG combination had the worst survival rate（31.85%）， while the survival rate of other combinations were all above 50.00%. Scion/rootstock diameter ratios of GK and YT combinations were 1.00，that of ZG combination was 0.83，which was the maximum difference from 1. The growth indexes of combinations indicated that grafted seedling of ZT，GT and YT combinations grew vigorously，while ZG and HG combinations had poor growth potential. There were significant differences in physio-biochemical similarity among some combinations（P<0.05）. The least absolute value of soluble protein content difference and soluble sugar content difference was observed in HK and ZT combination，the ZK and YT combinations showed the absolute value of polyphenol oxidase（PPO） and peroxidase（POD）activity difference. Four main related indexes were screened from the 10 indexes by principal component analysis，which were new shoot length，survival rate，the absolute value of soluble sugar content difference and POD activity difference between rootstock and scion. The result of membership function method showed the order of the graft compatibility of combinations. Jinghuang stock-scion combinations from high to low was GJ>YJ>HJ>XJ>ZJ， Tainong No.1 was YT>GT>ZT>XT>HT，Kaite was GK>ZK>XK>YK>HK，Guifei was GG>YG>XG>HG>ZG，and Renong No.1 was GR>XR>HR>ZR>YR. The cluster analysis showed that 25 stock-scion combinations were divided into 4 clusters，including one combination，namely YT combination，in group high compatibility，and twelve combinations in group relatively high compatibility，eleven combinations in group medium compatibility and one combination，namely ZG combination，in group incompatibility.【Conclusion】The new shoot length，survival rate，the absolute value of soluble sugar content difference and POD activity difference between rootstocks and scions are credible indexes for evaluation of early graft compatibility in mango. It is suggested that Tainong No.1 can be grafted with Yingzui；Jinghuang can be with Yingzui and Guangdongtumang，Kaite，Renong No.1 and Guifei can be with Guangdongtumang. Guifei can not be with Zihua No.3.