The Amur Grape (Vitis amurensis Rupr.) cultivars ’shuangFeng’ and ‘ZuoShanyi’ were grown in shelter greenhouse under natural sunlight and subjected to drought. Sap flow rate, net photosynthetic rate (P _N), and chlorophyll (Chl) fluorescence were measured on Amur Grape leaves subjected to different drought treatments. Significant decreases in P _N were associated with increasing intercellular CO₂ concentration (C _i), suggesting that the reduction in P _N was caused by nonstomatal limitation. Analysis of OJIP transients according to the JIP-test protocol revealed that specific (per PSII reaction center) energy fluxes for light absorption, excitation energy trapping and electron transport have significantly changed. The appearance of a pronounced K-step and J-step in polyphasic rise of fluorescence transient suggested the oxygen-evolving complex and electron transport were inhibited. Drought stress has relatively little effect on the parameter maximal quantum yield of PSII photochemistry (F_v/F_m), but the performance index (PIABS) is more sensitive in different drought treatment. There are cultivar differences in the response of PSII activity to drought, the photosynthetic apparatus of ‘ZuoShanyi’ cultivar is more resistant to drought than that of ‘ShuangFeng’, and JIP-test could be a useful indicator for evaluation and selection to drought tolerance.

Pathogen isolation and identification were performed on Actinidia arguta ‘Longcheng No. 2’ occurring bacterial canker from Liaoning Province, China. The pathogenic bacteria were identified as Pseudomonas syringae pv. actinidiae (Psa) by the analysis of morphology,16S rRNA and gyrB sequence, which were identified as Psa biovar 2 by Psa-specific primer sequence analysis. The pathogenicity tests were carried out with the isolate ‘R12’ and type strain ‘M228’ (biovar 3) as a control; the results showed that the phloem of green stems in A. arguta ‘Kuilv’ could be infect rapidly by R12, and milky mucus flowed from wounds, then the phloem turned black-brown, but it had strong resistance to Psa M228. In order to evaluate the resistance on Psa R12, 54 A. arguta germplasm resources were infected by artificial inoculation of stems, with A. deliciosa cv. ‘Hongyang’ and A. chinensis cv. ‘Xuxiang’, as control plant material, and their resistance levels were classified according to the disease index. The 54 tested materials exhibited differences in resistance to Psa R12, but no immune materials were found. In general, the germplasms were divided into five disease resistance categories, including 2 accessions with high resistance ‘Jianfengkuilv’ and ‘TL20013’, accounted for 3.70% of all the inoculated accessions; there were 11 resistant accessions, 15 tolerant accessions, 21 susceptible accessions, 5 highly susceptible accessions among them, accounted for 20.37%, 27.78%, 38.89% and 9.26%, respectively. In this study, the screening of disease-resistant germplasms could lay a foundation for further research on gene mapping, resistance mechanisms and breeding-resistant varieties of A. arguta to Psa.