Chemical Inducers Of Acquired Resistance Induced Effect On Several Crops

Up to date, it has been proved that BTH can effectively induce SAR in plants to pathogens. In this research, the investigated results are as follows: 0.125 ig/gBTH had no significant effect on germination of conidia and mycelium growth of Cladosporium cucumerinum ,so the reason why the rate of disease plants and leaves reduced was mainly because of the BTH-induced resistance. BTH at different concentrations used in the experiment can induce some degree of resistance to C.cucumeirinum, and the effect of induced resistance was. increased with the increase of BTH concentrations, but the optimum concentration was lii g 1g. After being pretreated by I ii g IgBTH,the average effect of induced resistance in Changchunmici, Jinyan7 and Jinchun3 was 91.17%, 80.9% and 97.07%,respectively. 0.125 igIgBTH-induced resistance to C.cucumeirinum reduced gradually with the time development, for example, the observed data at the 1 st,2nd,3rd and 4th time was 100.00%, 94.36%, 94.50% and 75.83%,respectively. I i g/gBTH-induced resistance in cucumber seedlings was far stronger than that of 0.l%Salicylic Acid,0.l%Phenol and 0.l%KC1-induced,the average effect of BTH-treated resistance in Changchunmici seedlings was 83.90%,but after being treated by Salicylic Acid, Phenol and KC1, the average effect was only 17.1 7%,32.42% and 33 .24%,respectively. All peroxidase(POD),polyphenoloxidase(PPO) and phenylanine ammo- nialyase(PAL) activities in cucumber and wheat were increased differently after being treated by BTH or inoculation with pathogens, but BTH-treated enzyme activities were increased quickly and highly than those pathogen-inoculated. The isozyme patterns of POD on polyacrylainde gels showed that there was 2 novel isozymes induced by either BTH or C.cucutnerinutn in cucumber,in wheat, 3 novel isozymes induced, what's more, the BTH-induced or pathogens-inoculated isozyme colour was more darker than that of neither BTH-treated nor pathogen-inoculated. 10-460 ii gIgBTH gave weak protection to susceptible variety of wheat- Mingxianl69 against Puccinia f.sp.tritici,l60 ig/gBTH-treated disease severity was reduced from 33.3 3% in the controls to 11 .42%,disease index was reduced from 51.25% in the controls to 3 2.22%. ft Treatment of susceptible variety of wheat-Longjian 46 by 10-460 g/gBTH also had some degree of effect on infection of Blutneria f.sp.fritici, eg., pretreatment by 10 or 160 t g/gBTH ,the rate of disease leaves was reduced from 34.87% in the controls to 26.25% and 5.2 l%,the rate of disease leaves was reduced from 100.00% in the controls to 93.75% and 77.22%,respectively.