Screening Of Rice Blast Resistant Germplasm Resources And Evaluation Of High-yield,Disease-resistance With High-quality Of Some Restorer Line Materials

As the main food crop in China,it is important to the national economy.The rice blast,sheath blight and bacterial blight are known as the three major rice diseases in the world,which seriously affect the yield and quality of rice.Therefore,the collection of rice germplasm resources and the selection of high-quality,high-yielding,disease-resistant rice varieties with excellent overall characteristics are the main direction of agricultural research.In this study,based on the analysis of the physiological race composition of rice blast fungus in Chongqing rice area,24 rice blast-resistant single-gene lines,27 Xinong 1B mutants and 17 rice blast-resistant restorer lines were identified and tested for resistance to rice blast seedling blast,leaf blast and panicle neck blast,respectively.Then,the resistance identification of sheath blight and bacterial blight was carried out on 11 rice blast-resistant restorer line resources with a disease resistance frequency greater than 85%of the total rice blast population.The yield characters and rice quality characters of these 11 restorer lines resistant to rice blast were determined.The main results of this study are summarized as follows:1.Screening of rice blast resistant germplasm resources（1）Selection of spikelet standard samples of rice blast54 effective strains were divided into 6 Chinese physiological groups and 14physiological races.The ZB was the dominant race group and ZB₁₅ was the dominant physiological race.The ZC group was an important race group and ZB₁was an important physiological race.（2）Determination of rice blast resistance spectrum of tested materials（1）Among the 24 rice blast resistance monogenic lines,the highest resistance frequency to isolates inoculated was IRBLta2-Pi（Pita2）,reaching to 90.74%.IRBLta2-Pi（Pita2）,IRBLkh-K3（Pikh）and IRBLi-F5（Pii）were resistanced to the ZA physiology group.The resistance frequency to ZB,ZC,ZD,ZE,ZG race groups of IRBLta2-Pi（Pita2）were closer to Tetep and IRBLta2-Pi（Pita2）can be used as a resistance source in Chongqing.（2）The resistance spectrum of Xinong 1B mutants Z47-X,Z47-3,K8005-1 and K6042 were significantly wider than that of the wild type.（3）The resistance frequency to isolates inoculated of J5874 and J5967 were consistent with Tetep.The resistance spectra of J5874,J5967,J5865,J6046,J6071,J5966,J5976,J6032,J6093,J5841 and J6037 were obviously wider than Sichuan resistance source 99-14.It showed that its broad-spectrum resistance was significantly stronger than that of 99-14.（3）Determination of rice blast resistance of tested materials（1）Among the 24 rice blast-resistant monogenic lines,IRBLta2-Pi（Pita2）was high resistance to seeding blast.IRBLz5-CA（Piz5）was high resistance to leaf blast.IRBLta2-Pi（Pita2）,IRBLk-Ka（Pik）,IRBL7-M（Pi7）and IRBL5-M（Pi5）had the resistance to panicle blast.IRBLta2-Pi（Pita2）was a monogenic resource of rice blast resistance with high resistance to seedling blast,leaf blast and panicle neck blast.（2）Among the 27 Xinong 1B mutants,K6104-1 and K6104-2 were high resistance to seedling blast.The leaf blast resistance of K8094 and K6104-2 mutants was significantly stronger than that of wild type.The diseased panicle neck blast rate of five mutants such as K6056、K8178、K8015、K6077 and K6106 were significantly stronger than that of the wild type.（3）Among the 17 blast resistant germplasm resources,J5865,J5874 and J6046were highly resistant to seedling blast.The leaf blast grade of 12 materials including J5841,J5847 and J5865 were highly resistant to leaf blast.14 materials such as J5841,J5847 and J5865 were highly resistant to panicle neck blast.Cluster analysis showed that the four materials J5865,J5874,J6046 and J6093 were clustered with the traditional resistant source Tetep.They were blast resistant quality resources with high resistance to seedling blast,leaf blast and panicle neck blast.2.Evaluation of high-yield,disease-resistance with high-quality of some restorer line materials（1）The four restorer line resources J5865,J5874,J5976 and J6032 had good resistance to sheath blight and could be used as breeding parents for resistance to sheath blight.（2）The six rice restorer line resources J6093,J5966,J5967,J5976,J6046 and J6071 had good resistance to bacterial blight and could be used as breeding parents for resistance to bacterial blight.（3）The combined results of rice blast,sheath blight and bacterial blight showed that J5865,J5976 and J6032 had good resistance to rice blast,sheath blight and bacterial blight.In addition,J5874 was both resistant to rice blast and sheath blight.J6093,J6046,J6071,J5841 and J5966 were both resistant to rice blast and bacterial blight.The preliminary results showed that these multi-resistance rice restorer line resources had great application value in breeding.（4）The three rice restorer line resources J6032,J6046 and J6071 had seed setting rate were over 80%,the grain weight per plant were over 29g,and the yield were range 493.37 to 543.80 Kg/667m².The coefficients of grain weight per plant,yield,effective panicle per plant and thousand-grain weight were larger.（5）The rice quality inspection index of J6046 reaches the level 3 of the agricultural industry standard.The ten rice restorer line resources J5847、J5865、J5874、J5966、J5967、J5976、J6032、J6071、J6093 and J5841 did not meet the standard of high-quality rice,chalky rice rate and chalkiness degree.The coefficients of alkali spreading value,chalkiness degree and chalky rice rate were larger.