Inheritance Pattern of Two-line Hybrid Rice Resistance to False Smut

[Objective] The aim of this study was to explore the inheritance pattern of the resistance of two-line hybrid rice to false smut. [Method] A moderate susceptible TGMS line 33S as the female parent, was crossed with 30 susceptible restorer lines and 23 resistant restorer lines. Then false smut resistance of the hybrid F1 and parents were identified. [Result] All F1 of 33S crossed with 30 susceptible re- storer lines were susceptible to rice false smut. The F1 of 33S crossed with 23 re- sistant restorer lines showed dominant, incompletely dominant or recessive inheri- tance. Dominant and incompletely dominant inheritance accounted for 87.0%. The diseased panicle rate, disease index, average diseased grains per panicle, and the highest diseased grains per panicle of F1 shared highly significant positive correla- tions with corresponding indicators of restorer lines. [Conclusion] This study provides references for genetic improvement of two-line hybrid rice.

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.

Inheritance study on the stable herbicide resistance of transgenic rice

The transgene technology showed a potentiali-ty in crop improvement such as disease and in-sect resistance,anti-adversity,and grain qual-ity.The inheritance of bar gene for herbicideBASTA resistance in stable transformed ricelines was studied for an understanding of theforeign gene inheritance pattern. BASTA resistant transgenic rice plantletswere regenerated from the embryos of rice va-rieties JY119 bombarded with bar gene.A sta-ble BASTA resistant TRline was consecutiv-

INHERITANCE OF RESISTANCE TO CYHALOTHRIN IN THE HOUSEFLY(DIPTERA:MUSCIDAE)

The genetic inheritance of resistance to cyhalothrin in housefly, Musca domestica (L) was investigated. Reciprocal crosses between susceptible (S) and resistant (R) strains were used to determine the characteristics of resistance. Analysis of probit line from the F 1 generation and F 2 generation obtained by inbreeding the F 1 hybrids indicated that cyhalothrin resistance was controlled by more than one factors and degree of resistance dominance to cyhalothrin was -0.10, indicating cyhalothrin resistance is conferred by incompletely recessive gene(s). The realized heritability of resistance to cyhalothrin cyhalothrin calculated from data collected routinely from laboratory selection was 0 12.

Identification of the novel recessive gene pi55(t) conferring resistance to Magnaporthe oryzae

The elite rice cultivar Yuejingsimiao 2 （YJ2） is characterized by a high level of grain quality and yield, and resistance against Magnaporthe oryzae. YJ2 showed 100% resistance to four fungal populations collected from Guangdong, Sichuan, Liaoning, and Heilongjiang Provinces, which is a higher frequency than that shown by the well-known resistance （R） gene donor culti- vats such as Sanhuangzhan 2 and 28zhan. Segregation analysis for resistance with F2 and F4 populations indicated the re- sistance of YJ2 was controlled by multiple genes that are dominant or recessive. The putative R genes of YJ2 were roughly tagged by SSR markers, located on chromosomes 2, 6, 8, and 12, in a hulked-segregant analysis using genome-wide selected SSR markers with F4 lines that segregated into 3 resistant （R）： 1 susceptible （S） or 1R：3S. The recessive R gene on chromosome 8 was further mapped to an interval ~1.9 cM/152 kb in length by linkage analysis with genomic position-ready markers in the mapping population derived from an F4 line that segregated into 1R：3S. Given that no major R gene was mapped to this inter- val, the novel R gene was designated as pi55（t）. Out of 26 candidate genes predicted in the region based on the reference genomic sequence of the cultivar Nipponbare, two genes that encode a leucine-rich repeat-containing protein and heavy-metalassociated domain-containing protein, respectively, were suggested as the most likely candidates for pi55（t）.

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.