Inheritance of Resistance to SMV3 and Identification of RAPD Marker Linked to the Resistant Gene in Soybean

One SMV resistant soybean line (95-5383) was crossed with four susceptible soybean varieties/ line (HB1, Tiefeng21, Amsoy, Williams) and one resistant introduced line PI486355. Their F, and F2 individuals were identified for SMV resistance by inoculation with SMV3. The results showed that in the four crosses of resistant X susceptible, F1 were susceptible and the ratio of F2 populations was 1 resistant : 3 susceptible (mosaic and necrosis), indicating that 95-5383 carries one recessive gene that confer resistance to SMV3. There is segregation of susceptibility in F2 progenies from the cross of 95-5383 X PI486355, indicating that the SMV3 resistant gene in 95-5383 is located at different locus from PI486355. By bulked segregating analysis (BSA) in F2 populations of 95-5383 X HB1, one codominant RAPD marker OPN11980/1070 closely linked to SMV3 resistance gene amplified with RAPD primer OPN11 was identified. The DNA fragment OPNll980 was amplified in resistant parent 95-5383 and resistant bulk, and OPN111070 was amplified in susceptible parent HB1 and susceptible bulk. OPNll980/1070 was amplified in F,. Identification of the markers in F2 plants showed that the codominant marker OPNll980/1070 is closely linked to the SMV resistance locus in 95-5383, with genetic distance of 2.1cM.

Analyses of gene effects and inheritance of resistance to bacterial blight in rice

We analyzed the resistant inheritance of ajaponica variety,Jia23,to two bacterial blightpathogen strains,KS-6-6 and Zhe 173,rep-resenting respectively the two predominantpathogenic types(Ⅱ and Ⅳ)in the rice crop-ping area along the Yangtze River Valley.Jia23 was crossed with susceptible vari-eties,Ewan8 and 7416.Fplants were back-

Inheritance of resistance to bacterial streak and bacterial blight in rice

Bacterial streak (BS) caused by Xanthomonascampestris pv. oryzicola has become one of themajor diseases in southern rice areas. Up todate, there are few reports on the inheritanceof resistance to BS and its relationship with theresistance to bacterial blight (BB). Therefore,we analyzed the inheritance of resistant to BSin three resistant rice cultivars and the geneticrelationship of resistance between BS and BB.

Verification test on an innovated method for the studies on inheritance of resistance to rice sheath blight

We have recently developed a systematic method for the study on the inheritance of resistance to sheath blight. The key of the system is an innovated method of inoculation and investigation along with the employment of the permanent population. This paper reported the procedure of the system and the result of its verification.

Genetics and Molecular Marker Identification of a Resistance to Glomerella Leaf Spot in Apple

Apple Glomerella leaf spot(GLS) is a destructive fungal disease that damages apple leaves during the summer in China.Breeding new diseaseresistant varieties is considered to be the best way of controlling GLS.A genetic study of resistance to Glomerella leaf spot(GLS) in apple was conducted by using four F_1 hybrid groups(‘Fuji' בGolden Delicious',‘Golden Delicious' בFuji',‘Gala' בFuji',and ‘Fuji' בQF-2') generated from two highly resistant varieties or selections,‘Fuji' and ‘QF-2',and two highly susceptible varieties,‘Golden Delicious' and ‘Gala'.The results showed that the separation ratios of resistant plants to the susceptible ones in the four F_1 hybrid groups were statistically consistent with the theoretical ratios of 1:1,1:1,0:1,and 1:0.Comprehensive analysis enabled us to generate the following conclusions:GLS resistance in apple may be controlled by a single recessive gene.The genotype of the resistant plants was rr,whereas the genotypes of the susceptible ones were RR and Rr.By using ‘Golden Delicious' בFuji' F_1 hybrid groups and the bulked segregation analysis(BSA) method,the marker S0506206-243 bp associated with disease resistance character to GLS was identified through screening 500 SSR primers encompassing the entire apple genome with even coverage,and the genetic distance between the marker and the GLS resistance gene was 9.8 cM.