Identification Of Resistance To Magnaporthe Grisea In RiceVarieties And Effect On Callus Tissue From The Rice Mature Embryo Treated By Blast Fungus Crude Extraction

Rice blast, causeed by Magnaporthe grisea, is one of the most important diseasesin rice, which distributes in rice areas in the world. The development of breeding blastresistant varietiess is the best economical and effective measure for blast management.And resistance identification is one of the most principal means as effectivelybreeding blast resistance varietiess.Different methods were used to indentify the blast resistance of 16 rice varietieswith virulent blast isolate, 193(ZB₂₅), and assay of bio-chemical mechanism on the 6representative rice varieties was conducted. Based on above research, the matureembryo of highly two suscepitible varieties treated the crude extrction of the 193 blastsolate was studyied, influenced on the rice callus tissue culture. The trial result was asfollows:1. 16 varieties tested using leaves in vitro and 3-4 leaf age at seedling stageshowed that their R-reactions were accordance rate as same as above 90%. Relativelyspeaking, the leaf in vitro noculation had shorter test time and less room than at 3 to 4leaves stage. Hence, this method could be used in identification of varieties blastresistance.2. The results of study showed that most of the bio-chemical factors of resistantvarieties were significantly different from those of sencitivity varieties. The results w-ere as following: the activities of POD, PPO, PAL in resistant varieties weresignificantly higher than those in suscepitible varieties and the increase of theactivities in resistant varieties was higher than those in suscepitible varieties, all theenzyme activities rose at this and then descended both in resistant varieties andsuscepitible varietiess; the activity of APX in resistant varietiess and suscepitible varieties appeared up first and down later, but the rising rate was higher and the netincrease was bigger in resistant varietiess than in suscepitible varieties;the ASAcontent in resistant varieties was not ignificantly different from its control(un-inoculated seedlings), while the one in suscepitible varieties decreased at this andthen increased;content of soluble protein both in resistant verieties and suscepitiblevarieties decreased and then increased. The greater the increase of the content, and thehigher the net increase, the better the expression the rice blast resistance was.3. The results showed that the crude extraction inhibited the callus inducementand differentiation of the rice mature embryo, the regenerative plant protein contentwas significantly increased.