Research On The Regularities Of Distribution Of The Magnaporthe Grisea Physiological Strain In Sanjiang Plain And The Identification Containing Resistance Gene Pigm

Rice blast is one of worldwide fungous diseases which are very popular and harmful, and itacts an important factor that limits rice having a stable and high yield. It almost happens in everyrice area, and when it happens, it can generally make the yield of rice reduce by10%²0%. Whilein epidemic years, it can lead to the decline of rice harvest by40%⁵0%. What’s more, when it isvery serious, it can make the rice production reduce by80%even become sterilized. Thisexperiment mainly does an research on the regularities of distribution of Magnaporthe Grisea andphysiological strain in Sanjiang Plain in Heilongjiang Province. The research identified the maincultivars in Heilongjiang Province and seedling resistance of donor parents Gumei4carrying ofrice blast resistant gene pigm, and detected the Distribution situation of pigm existing in ricegermplasm resources in Heilongjiang Province by using molecular markers.The experiment adopted identification method used by the China Magnaporthe Griseaphysiological strain joint test group in1980. The7uniformed varieties of identification included:Tetep, Zhenlong13, Sifeng43, Dongnong363, Guandong51, Hejiang18, Lijiang Xituan Heigu.Heilongjiang’s main grown varieties are Kongyu131, Kendao12, Longjing20, Longjing21,Longjing25, Longjing26, Longjing29, Longjing24, Longjing27, Kenjiandao6, Songjing12,Beidao3, suijing12, Suijing7, Songjing9, Songjing6.When the seedlings had3⁴leaves, webegan to have it inoculated.7to10d after the inoculation, research was conducted to investigatethe pathogenesis, the host reaction type was R, M, S respectively.Donor parent Gumei4, MP4, as well as the widely grown rice varieties in HeilongjiangProvince and some excellent germplasm resources was used to mark dominant molecular ofMagnaporthe Grisea resistant gene pigm. Take10g of fresh leaves from each variety in theflourishing period of, and use SDS trace extraction method to get DNA. PCR amplification primersusing dominant molecule to mark m26205, which could specifically amplify the correspondingsequences of the resistance allele pigm, the primer could amplify2strips, corresponding to pigm1and pigm3respectively. Observe directly under the UV lamp or scan the recording electrophoresisresults by using the gel scanning imaging system.1. Test was done to monitor the physiological race in2011, in which7groups,19China strainwere detected, they were: ZA₁, ZA₄₉, ZA₅₃, ZA₅₇, ZA₆₁, ZB₁, ZB₅, ZB₁₇, ZB₂₁, ZC₁, ZC₂, ZC₅, ZD₁,ZD₅, ZD₇, ZE₁, ZF₁, ZF₂, ZG₁. Group ZD had the highest flora frequency, followed by group ZB,group ZA, whose frequency of occurrence were respectively39.9%,19.3%,15.6%and they werethe main flora in Sanjiang plain currently. The frequency of occurrence of strain were ZD₅, ZB₁,ZD₁, reaching28.2%,11.6%,10.7%respectively, all of which had advantages in production.Seven China races that could infect rice identification of varieties was detected accounted for aproportion53.34%in all the races that had been detected physiological race. Especially, the ZD₅had the highest occurrence of frequency, and it had a great influence on rice production varieties. 2. The result of the identification on the resistance mainly planted rice in HeilongjiangProvince showed that: Kongyu131, Kendao12, Longjing25, Longjing26, Longjing24, Longjing27, Kenjiandao6, had a poor resistance, especially Kongyu131, Kendao12, Longjing26,Longjing27, which were infected disease by almost all races. Longjing21, suijing12, Suijing7,Songjing9, Sonjing8and Songjing6were resistant to disease moderately; Longjing20, Longjing29, Suijing9, Songjing12, Beidao3could resist disease strongly.3. Gumei4was the gene carrier of pigm’s blast resistance, showing resistance to all the15races that had been detected. ZA₁, ZA₅₃, ZA₅₇, ZA₆₁, ZB₁₇, ZC₂, ZD₁, ZD₇, ZE₁, ZF₁, ZF₂and ZG₁did not cause the infection. Gumei4also showed strong resistance to the infection of ZB₁, ZD₅,and these two varieties were detected with a high frequency in physiological races in2010. ZA₄₉,ZB₅, ZB₂₁, ZC₁, ZC₅could infect Gumei4at a high frequency, but the number of occurrence wasnot very big, meanwhile, Gumei4showed a strong resistance to it, the above results suggested thatGumei4had a wide resistance spectrum to the rice blast sirens and dominant races and importantraces.4. The results of PCR, Gumei4（GM4） and MP4as positive control, in the117rice varieties,only2species （corresponding Suijing4, Ken94437respectively） can be amplified2strips（respectively Pigm1and Pigm3）, showing that rice blast resistant gene pigm existed in the2varieties, but vast majority of varieties didn’t contain pigm.