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1.
BACKGROUND: Beta-cypermethrin, a synthetic pyrethroid insecticide, was applied frequently in the control of health pests including houseflies, Musca domestica L., in China. However, different levels of resistance to beta-cypermethrin were monitored in field strains of houseflies. A strain of M. domestica, 4420-fold resistant to beta-cypermethrin after continuous 25 generations of selection, was used in this paper to determine the mode of inheritance of pyrethroid resistance. RESULTS: The estimated realized heritability (h(2)) of beta-cypermethrin resistance was 0.30 in this resistant strain. Results of bioassays showed no significant difference in values of LD(50) and slope of log dose-probit lines between reciprocal progenies F(1) and F'(1), and yielded values of - 0.10 (F(1)) and - 0.11 (F'(1)) for the degree of dominance (D). Chi-square analysis from responses of self-bred and backcross progenies (F(2), BC(1) and BC(2) respectively) indicated that the null hypothesis, a single gene responsible for resistance, was accepted. The minimum number of independent segregation genes was 0.93 for F(1) by Lande's method. CONCLUSION: It was concluded that beta-cypermethrin resistance in the housefly was inherited as a single, major, autosomal and incompletely recessive factor. These results would provide the basic information for pest management programmes.  相似文献   

2.
ABSTRACT The inheritance of resistance to Leptosphaeria maculans, the causal agent of black leg of crucifers, was studied in Brassica juncea. Three resistant accessions (UM3021, UM3043, and UM3323) and one susceptible accession (UM3132) of B. juncea were crossed in a complete diallel. Parents, F(1), and F(2) progenies were evaluated for all crosses using both cotyledon and stem inoculation. Cotyledon reaction was evaluated with two isolates of L. maculans, but stem reaction was evaluated with one isolate. Disease reactions observed for individual plants were the same for both inoculation methods and for both isolates of the pathogen for cotyledon reaction. No segregation was observed for the crosses between resistant accessions (UM3043 x UM3323 and UM3021 x UM3323), but a few susceptible plants were observed in the F(2) progeny of crosses between resistant parents (UM3021 x UM3043). This was probably due to heterozygosity in some parental plants of UM3021. For crosses be tween the susceptible parent and resistant parents, F(1) plants for two crosses were all resistant. For cross UM3132 x UM3021, some susceptible plants occurred, which was also suggestive of heterozygosity in UM3021. Although resistance in F(1) was dominant, for F(2) populations, segregation fit either 13:3, 3:1, or 1:3 ratios, indicating that resistance can be either adominant or recessive trait. F(3) families derived from some susceptible F(2) plants from crosses UM3021 x UM3132 and UM3043 x UM3132 were evaluated using the cotyledon inoculation method only. Segregation of F(2) plants and F(3) families in crosses involving resistant and susceptible parents indicated that the resistance to L. maculans in B. juncea is controlled by two nuclear genes with dominant recessive epistatic gene action.  相似文献   

3.
ABSTRACT This study describes the segregation of genes for resistance to the fungus Puccinia triticina in a cross between partially resistant wheat lines L-574-1 and CI 13227 with two and four genes for resistance, respectively. The objectives of this study were to use parental, F(1), F(2), and backcross populations to quantify maternal effects, degree of dominance, and transgressive segregation, and to determine whether CI 13227 and L-574-1 share any resistance genes for long latent period or small uredinia. In two experiments conducted in the greenhouse, the uppermost leaf of adult wheat plants was inoculated prior to heading with P. triticina. On days 6 to 21 after inoculation, the number of uredinia that erupted from the leaf surface was counted and used to calculate the mean latent period (MLP). The length and width of five arbitrarily selected uredinia were measured and used to calculate uredinium area. Midparent values, degree of dominance, and broad-sense heritability were calculated for MLP and uredinium area. For experiment A, MLP values for CI 13227, L-574-1, F(1), and F(2) generations were 12.2, 10.5, 10.2, and 10.6 days, respectively. For experiment B, MLP values for CI 13227, L-574-1, F(1), F(2), backcross to CI 13227, and backcross to L-574-1 were 12.3, 10.0, 10.6, 10.8, 11.1, and 10.0 days, respectively. The inheritance of long latent period was partially recessive, and no maternal effect was present (P = 0.62 to 0.87 for the comparison of means in reciprocal crosses). Broad-sense heritability for MLP ranged from 0.72 to 0.74, and there was transgressive segregation in the F(2) and backcross populations. Uredinia of the F(1) generation were slightly larger than uredinia for CI 13227. The inheritance of uredinium size was partially dominant, and no maternal effect was present (P = 0.5 to 0.63). Broad-sense heritability for uredinium area ranged from 0.36 to 0.73 and transgressive segregation was present in the F(2) and backcross populations. The results for MLP indicate that lines CI 13227 and L-574 likely share one gene for resistance (based on F(1) values) but not two genes (based on the presence of transgressive segregation). CI 13227 and L 574-1 appear to have at least one gene difference for uredinium area. The linear relationship between uredinium area regressed onto MLP was significant (P < 0.001) and r(2) values ranged from 0.14 to 0.26. These results indicate that the resistance in CI 13227 and L-574-1 could be combined to create wheat cultivars with greater partial resistance than that possessed by either parent based on MLP or uredinium size.  相似文献   

4.
ABSTRACT The recently described rust hybrid Melampsora xcolumbiana was discovered as a result of its novel pathogenic variation on Populus trichocarpa x P. deltoides (TxD) hybrid poplar. To characterize this pathogenic variation, 10 commercial TxD clones, all F(1) clones, were chosen as host differentials. Fourteen mononuredinial isolates of Pacific Northwestern field collections of M. xcolumbiana, from 1996 to 1998 inclusive, were determined to be 13 distinct pathotypes. In contrast, four Southeastern isolates of M. medusae could not be distinguished on the same TxD host differentials, although they can be distinguished as pathotypes using P. deltoides differentials. The first three pathotypes of M. xcolumbiana (Mxc1, Mxc2, and Mxc3) and a Mississippi isolate of M. medusae were inoculated onto a three-generation TxD pedigree, formerly used to characterize the Mmd1 gene for resistance to M. medusae. Resistance to the Mxc3 pathotype mapped to the same linkage group (group Q) as the Mmd1 gene. In contrast, linked genes for resistance to Mxc1 and to Mxc2 were located on linkage group O, and were unlike Mmd1 and Mxc3 in that they were inherited from P. deltoides. The latter two genes resembled Mmd1 and Mxc3 in that infection type was correlated with quantitative traits such as uredinial density and latent period. Pathogenic variation in M. xcolumbiana matches resistance genes from both P. trichocarpa and P. deltoides and reveals the vulnerability to hybrid rust of commercial TxD hybrid poplar clones.  相似文献   

5.
Tan spot of wheat, caused by the fungus Pyrenophora tritici-repentis, is a destructive disease worldwide that can lead to serious losses in quality and quantity of wheat grain production. Resistance to multiple races of P. tritici-repentis was identified in a wide range of genetically diverse genotypes, including three different species Triticum aestivum (AABBDD), T. spelta (AABBDD), and T. turgidum (AABB). The major objectives of this study were to determine the genetic control of resistance to P. tritici-repentis races 1 and 5 in 12 newly identified sources of resistance. The parents, F(1), F(2), and F(2:3) or F(2:5) families of each cross were analyzed for the allelism tests and/or inheritance studies. Plants were inoculated at the two-leaf stage under controlled environmental conditions and disease reaction was assessed based on lesion-type rating scale. A single recessive gene controlled resistance to necrosis caused by P. tritici-repentis race 1 in both tetraploid and hexaploid resistant genotypes. The lack of segregation in the inter- and intra-specific crosses between the resistant tetraploid and hexaploid genotypes indicated that they possess the same genes for resistance to tan necrosis and chlorosis induced by P. tritici-repentis race 1. A single dominant gene for chlorosis in hexaploid wheat and a single recessive gene for necrosis in tetraploid wheat, controlled resistance to P. tritici-repentis race 5.  相似文献   

6.
Bonos SA 《Phytopathology》2006,96(8):808-812
ABSTRACT The dollar spot disease incited by Sclerotinia homoeocarpa is an important disease of creeping bentgrass (Agrostis stolonifera). Genetic resistance is an important control strategy and could reduce fungicide use. Despite recent research, the genetic mechanism of dollar spot resistance in turfgrasses is still not fully understood. The objectives of this study were to (i) determine narrow-sense heritability and predicted gain from selection for dollar spot resistance in creeping bentgrass and (ii) evaluate inheritance characteristics of dollar spot disease resistance. Inheritance characteristics such as the detection of major genes, heterosis, maternal effects, and combining ability were determined by evaluating the disease severity of progeny from crosses between resistant and susceptible bent-grass clones. Parental clones and progenies from crosses were established in a field trial in a randomized complete block design and inoculated with one isolate of S. homoeocarpa applied at a rate of 0.25 g m(-2) of prepared inoculum. Differences in progeny means between crosses were observed over both years. Progeny from resistant x resistant crosses had significantly less disease severity than resistant x susceptible and susceptible x susceptible crosses. High narrow-sense heritability estimates (0.79 [2002], 0.79 [2003]) and large mean squares for general combining ability support the idea that additive gene action plays a significant role in disease resistance and support previous research that dollar spot resistance is most likely quantitatively inherited.  相似文献   

7.
ABSTRACT The inheritance of resistance to Aspergillus ear rot and aflatoxin production in corn (Zea mays L.) caused by Aspergillus flavus was studied in progeny derived from crosses between the resistant corn inbred cv. Tex6 and susceptible inbred cvs. B73 and Mo17. From 1994 to 1996, plant generations included were the P(1) (susceptible B73 or Mo17), P(2) (resistant Tex6), F(1), F(2), F(3), BCP(1), BCP(1)-selfed, and BCP(2). The BCP(2)-selfed generation was added in 1995 and 1996 for the B73 x Tex6 cross. Primary ears were pinboard inoculated and evaluated for Aspergillus ear rot severity. F(1) means deviated from the midparent value toward resistance for aflatoxin production and toward susceptibility for ear rot in both crosses. Analyses of generation means indicate that additive gene action was most important in the resistance to both ear rot and aflatoxin production in the B73 x Tex6 cross. Mo17 was somewhat resistant to both traits, so resistance from Tex6 was not well defined in this cross. Broad-sense heritabilities for ear rot and aflatoxin production were 58 and 63% for Mo17 x Tex6, and 66 and 65% for B73 x Tex6. Narrow-sense heritabilities for ear rot and aflatoxin production were 39 and 45% for B73 x Tex6. It is estimated that one cycle of selection for resistance within B73 x Tex6 F(3) families would reduce the percentage of ear rot severity by 8.5% and aflatoxin concentration by 19 ng/g.  相似文献   

8.
Jin Y  Steffenson BJ 《Phytopathology》2002,92(10):1064-1067
ABSTRACT Crown rust, caused by Puccinia coronata var. hordei, is a new disease threat to barley in the Great Plains region of the United States. Deployment of resistant cultivars is the only economically viable option for the control of this disease. Thus, the objective of this study was to investigate the sources and genetics of crown rust resistance in barley. A geographically diverse sample of barley germ plasm collected around the world (526 accessions total) was evaluated at the seedling stage to P. coronata var. hordei, and only 10 accessions (1.9% of the total) were found resistant. These 10 accessions were also resistant at the adult plant stage in a greenhouse test. Three F(2) populations (Bowman x Hor2596, MR x Hor2596, and MD x Hor2596) were developed to study the inheritance of crown rust resistance in the resistant line Hor2596 (CIho 1243). A close fit to a 3:1 ratio of resistant/susceptible plants was observed in all three populations and is consistent with the segregation of a single resistance gene. F(1) plants from the Bowman x Hor2596 population exhibited slightly higher infection types than the resistant parent, indicating incomplete dominance. The locus symbol Rpc1 and allele symbol Rpc1.a were recommended for the crown rust resistance gene in Hor2596. An attempt was made to associate the Rpc1 locus with one of the seven barley chromosomes by analyzing linkage data with previously mapped morphological markers in crosses with multiple recessive (MR) and multiple dominant (MD) morphological marker stocks. However, no close linkages were detected between Rpc1 and the 20 morphological markers present in the marker stocks. The resistant accessions identified in this study should be useful to breeders for developing barley germ plasm with crown rust resistance.  相似文献   

9.
Genetic tests were carried out in the greenhouse to determine whether resistance to Pseudomonas syringae pv. tomato in the tomato cultivar Ontario 7710 and in the wild accession PI 126430 (Lycopersicon pimpinellifolium) was controlled by different genes. Ontario 7710 (genotype of resistance Pto/Pto), PI 126430, their F! and F2 progenies and F( x susceptible progenies were tested for resistance to the bacterial speck pathogen. No lesions appeared on inoculated leaves in plants of Ontario 7710, PI 126430 and the Fj hybrid. F2 progenies segregated for resistance (symptomless) and susceptibility (50-80 lesions per plant) at a ratio of 15:1. Plants from the cross Fj x susceptible segregated at a ratio of 3 resistant: 1 susceptible. These data indicate that the gene for resistance in PI 126430 is different from that found in Ontario 7710. The gene symbol Pto-2 is proposed for the resistance factor in PI 126430.  相似文献   

10.
The aim of this study was to test whether resistance of clones of Theobroma cacao (cocoa) varied between isolates of Moniliophthora (formerly Crinipellis ) perniciosa , the cause of witches' broom disease. Developing buds of vegetatively propagated T. cacao grown in greenhouses in the UK were inoculated with 16 000 spores of M. perniciosa per meristem in water, under conditions where water condensed on the inoculated shoot for at least 12 h after inoculation. The proportion of successful inoculations varied between clones and was inversely correlated with time to symptom production or broom formation. A specific interaction was demonstrated among three single-spore isolates of M. perniciosa and the clone Scavina 6 (SCA 6) and a variety of susceptible clones. Isolates Castenhal-I and APC3 were equally likely to infect SCA 6 and the other clones, but isolate Gran Couva A9 never infected SCA 6, although it was as virulent on the other clones. The interaction was maintained when the wetness period was extended to 70 h. Offspring of SCA 6 × Amelonado matings were all susceptible to both Castenhal-I and GC-A5, with no evidence of greater variability in susceptibility to GC-A5 than Castanhal-I. This suggests recessive inheritance of a single homozygous factor conferring resistance to GC-A5, from SCA 6. The progenies were slightly more susceptible to Castanhal-I than GC-A5. The implications for managing the disease are discussed.  相似文献   

11.
Zhang ZJ  Yang GH  Li GH  Jin SL  Yang XB 《Phytopathology》2001,91(7):680-686
ABSTRACT Wheat (Triticum aestivum) cvs. Libellula (LB), San Pastore (SP), and Xian Nong 4 (XN4) possess durable resistance to stripe rust, caused by Puccinia striiformis f. sp. tritici, and cv. Ming Xian 169 (MX169) is highly susceptible to the rust. Inheritance of stripe rust resistance was studied by crossing the four cultivars and evaluating the resistance of parental, F(1), F(2), backcross, and F(3) plants in the fields. Transgressive segregation for resistance was observed in the resistant by resistant crosses of LB x XN4 and XN4 x SP, but not in cross LB x SP. These results indicate that (i) the resistance genes in XN4 are different from those in LB and SP, and (ii) LB and SP share common resistance genes. The number of genes segregating for the resistance was estimated by quantitative methods from the data of F(2), backcross, and F(3) populations. LB and XN4 appear to have two to three resistance genes, and SP appears to have two to four resistance genes when crossed with MX169. The resistance gene number in resistant by resistant cross LB x XN4 was four to five, approximately equal to the sum of the genes in LB and XN4. Similarly, the resistance gene number in cross XN4 x SP was approximately equal to the sum of the genes in XN4 and SP. Broad-sense heritability was high in all crosses except LB x SP. Compared with the three MX169-involved crosses, narrow-sense heritability was higher in LB x MX169 and SP x MX169 crosses than in the XN4 x MX169 cross. The LB x XN4 and XN4 x SP crosses showed moderate narrow-sense heritability.  相似文献   

12.
Coates ST  White DG 《Phytopathology》1998,88(9):972-982
ABSTRACT Three populations derived from crosses of selected resistant inbreds (061, B37HtN, and DS:74:1071) with susceptible inbred FR1141 and a population derived from a cross of B37 x B37HtN were evaluated for gray leaf spot severity in 1992 and 1993 at Urbana, IL, and Andrews, NC. Populations included the susceptible parent (P(1)), the resistant parent (P(2)), F(1) and F(2) generations, backcrosses BCP(1) and BCP(2), and, when space and seed were available, one or more of the F(3), BCP(1)S(1), and BCP(2)S(1) generations. Plants at Urbana were inoculated, and naturally occurring disease was relied upon at Andrews. Individual plants were rated by visually estimating the percent leaf area blighted (necrotic). Generation mean analysis of data combined over years or locations indicated that a simple additive-dominance model was able to explain the inheritance of resistance for all populations. Dominance effects were detected in all population evaluated. For the FR1141 x 061 and FR1141 x B37HtN populations, dominance was significant at early ratings, but not at late ratings. Results from generation mean analysis for individual years, locations, and rating were variable.  相似文献   

13.
Among 146 accessions of Lycopersicon pimpinellifolium , 132 of L. esculentum var. cerasiforme and 53 of L. peruvianum screened for resistance to powdery mildew, caused by Oidium lycopersici , a wide variation in reactions was found. Two plants of L. esculentum var. cerasiforme accession LA-1230 were resistant. One resistant symptomless plant of accession LA-1230, designated LC-95, produced homozygous resistant progenies. LC-95 was crossed with cv. Marmande (susceptible parent) and F1, F2 and backcrosses to the resistant and the susceptible parents were derived. These genotypes were grown in glasshouses at 23°C and 95–100% RH and inoculated with O. lycopersici . The F1 plants were susceptible. F2 and backcross segregations fitted the hypothesis of a single recessive gene which is here designated ol-2 .  相似文献   

14.
Newcombe G 《Phytopathology》2005,95(7):779-783
ABSTRACT Nonhost resistance is hypothesized to protect plants in a nonspecific manner. For highly specialized parasites, this hypothesis applies not only to distantly related plants but also to resistant congeners of the host species. Congeners of Populus spp. were hybridized to create two interspecific hybrid poplar pedigrees (i.e., Populus trichocarpa x P. deltoides and P. trichocarpa x P. maximowiczii). The pedigrees were planted in a randomized, replicated "common garden" on Vancouver Island so that they were exposed to parasites of the native P. trichocarpa. Monogenic and oligogenic resistance to two ascomycetous, parasitic fungi (i.e., Venturia inopina and a Taphrina sp.) segregated in a parasite-specific manner in each pedigree. However, these resistance genes were not inherited from the native host, P. trichocarpa. Instead, resistance was inherited from the allopatric, nonhost congeners, P. deltoides (eastern cottonwood) and P. maximowiczii (Japanese poplar). Thus, we found that major genes condition parasite-specific, nonhost resistance, as has been true in earlier studies of this kind with additional parasites of Populus spp. The selective force responsible for evolutionary maintenance of such genes is unknown.  相似文献   

15.
Penetration, development and emigration of M. arenaria in the roots of three Myrobalan plum (Prunus cerasifera) clones genetically characterized for their resistance to root-knot nematodes (RKN) were studied during the 10 (penetration) and 15 (emigration) days following the date of inoculation (D) of 2500 juveniles (J2s) per plant into the soil. Miniaturized tests were conducted on the two resistant clones P.2175 (Ma1 gene) and P.1079 (Ma2 gene) and the susceptible clone P.2032 (recessive for both genes), obtained from micropropagated plantlets and grown in mini-containers under controlled conditions at 25°C in a growth chamber. For penetration and development studies, nematodes in the roots were recovered by the acid fuchsin-lactophenol staining technique. Equivalent numbers of J2s were recovered in all the clones at D+1 and D+2. Subsequently, the numbers increased rapidly in P.2032 and were significantly different from those in P.1079 and P.2175 that remained at a low level. No swollen larvae were observed in the resistant clones. In P.2032, the first swollen larvae were observed at D+4, the first females were observed at D+12, whereas the first females with attached egg sacs and the first new-generation J2s were obtained between D+21 and D+28. Our data suggest that the resistance phenomenon does not act on the very early nematode penetration but acts later by preventing feeding-site induction and development into the third-stage. For emigration studies, plants in which J2s had been allowed to penetrate for two days (from D to D+2) were washed free of soil, repotted and then, after various periods of growth, soil-free roots were placed under a mistifier to evaluate the numbers of emigrating individuals. Emigration of J2s from the roots occured mainly from D+2 to D+4 in all the genotypes and was very limited from D+4 to D+10. There was no significant differences in the number of emigrated juveniles between the resistant and susceptible clones, indicating that emigration cannot explain the difference in the numbers of nematodes recovered in the roots.  相似文献   

16.
ABSTRACT The inheritance of resistance to aflatoxin production in corn (Zea mays) caused by the fungus Aspergillus flavus was studied following inoculation in progeny derived from the cross between the susceptible inbred B73 and the resistant inbred LB31. In 1993, the susceptible parent B73 (P(1)), resistant parent LB31 (P(2)), F(1), F(3), and BCP(1)-selfed generations were evaluated. In 1994, the study was expanded to include the F(2), BCP(1), and BCP(2) generations. Aflatoxin concentrations were higher in 1993 than 1994. Generation mean analysis showed that additive and dominant gene action were important for resistance to aflatoxin production. Potence ratios indicated dominance for resistance in both years. In 1993, aflatoxin values of the F(1) generation were significantly lower than the calculated mid-parent values, indicating dominant gene action favoring resistance. In 1994, values of the F(1) generation were not significantly lower than the calculated midparent value. The frequency distributions of aflatoxin values for families of the F(3) and BCP(1)-selfed generations were skewed toward the resistant parent, also indicating dominance. Heritability based on a progeny mean basis of F(3) families representing the additive variance plus one-fourth of the dominance variance was estimated at 66% over both years combined. Based on these results, selection for resistance to aflatoxin production in progeny derived from the cross between B73 and LB31 should be effective.  相似文献   

17.
Solanum nigrum, black nightshade, is a wild non-tuber bearing hexaploid species with a high level of resistance to Phytophthora infestans (Colon et al. 1993), the causal agent of potato late blight, the most devastating disease in potato production. However, the genetic mode of resistance in S. nigrum is still poorly understood. In the present study, two S. nigrum accessions, 984750019 (N19) and #13, resistant (R) and susceptible (S), respectively, to three different isolates of P. infestans, were sexually crossed. The various kinds of progeny including F1, F2, F3, and backcross populations (BC1; F1 × S), as well as two populations produced by self-pollinating the R parent and S parent, were each screened for susceptibility to P. infestans isolate MP 324 using detached leaf assays. Fifty seedling plant individuals of the F1 progeny were each resistant to this specific isolate, similarly to the seedling plants resulting from self-pollination of the resistant R parent. Thirty seedling plants obtained from self-pollination of the S parent were susceptible. Among a total of 180 F2 plants, the segregation ratio between resistant and susceptible plants was approximately 3: 1. Among the 66 seedling plants of the BC1 progeny originating from crossing an F1 plant with the susceptible S parent, there were 26 susceptible and 40 resistant plants to P. infestans. The segregation patterns obtained indicated monogenic dominant inheritance of resistance to P. infestans isolate MP 324 in S. nigrum acc. 984750019. This gene, conferring resistance to P. infestans, may be useful for the transformation of potato cultivars susceptible to late blight.  相似文献   

18.
The development of insecticidal resistance in diamondback moth (DBM) Plutella xylostella has immediate implications for its management. In this study, we examined the mode of inheritance of Indoxacarb resistance in P. xylostella. The indoxacarb-resistant strain (Px-R) was obtained through continuous laboratory selection with increasing doses of indoxacarb in each generation. At the 14th generation of selection, the resistance ratio of Px-R strains was 238 over the susceptible strain (Px-S). The mode of inheritance to Indoxacarb in P. xylostella was examined performing standard reciprocal crosses between Px-R and Px-S and response of Px-R, Px-S and F1 hybrid progenies to Indoxacarb through leaf dip bioassay. The degree of dominance (D) and heritability (h) of F1 hybrid progeny ranged from ?0.001 to 0.0012 and 0.499 to 0.506, respectively. The Indoxacarb resistance was appeared to be autosomal and inherited as a semi-dominant trait. The Px-R strain of P. xylostella showed little cross resistance to cypermethrin and there was no cross resistance to other pesticides viz., chlorpyrifos, spinosad, karanjin, xentari (Bta-Cry1C) and MVP-II (Cry1Ac). Since the Indoxacarb resistance inherited as a semi-dominant trait in P. xylostella, the sub lethal doses and frequent use of indoxacarb should be avoided for the management of P. xylostella. Moreover, Px-R of P. xylostella showed positive cross resistance to synthetic pyrethroids (cypemethrin), therefore indoxacarb and synthetic pyrethroids should not be recommended together for management of P. xylostella.  相似文献   

19.
Chen X  Line RF 《Phytopathology》1999,89(3):226-232
ABSTRACT Barley genotypes Abyssinian 14, BBA 2890, Grannelose Zweizeilige, PI 548708, PI 548734, PI 548747, and Stauffers Obersulzer are resistant to all races of Puccinia striiformis f. sp. hordei identified thus far in North America. Astrix, BBA 809, Bigo, Cambrinus, Emir, Heils Franken, Hiproly, I5, Mazurka, Trumpf, and Varunda have specific resistance to certain races, whereas Topper and Steptoe are susceptible to all races. Seedlings of parents and F(1), F(2), and F(3) progeny from crosses of resistant genotypes with Topper and Steptoe were tested for resistance to North American P. striiformis f. sp. hordei races PSH-1, PSH-4, PSH-10, PSH-13, and PSH-20. When tested with PSH-1, one recessive gene was detected in BBA 809, BBA 2890, Bigo, Hiproly, and Grannelose Zweizeilige; two recessive genes were detected in Emir, I5, PI 548708, PI 548734, PI 548747, Varunda, and Astrix; and one dominant gene and one recessive gene were detected in Abyssinian 14 and Stauffers Obersulzer. In tests with PSH-4, one recessive gene was detected in BBA 809, two recessive genes were detected in Trumpf, and two partially recessive genes were detected in Astrix. In tests with PSH-13, one recessive gene was detected in BBA 2890, Grannelose Zweizeilige, I5, and PI 548708 and two recessive genes were detected in Abyssinian 14, Hiproly, PI 548734, and PI 548747. In tests with PSH-20, one recessive gene was detected in Bigo and a recessive gene and a dominant gene were detected in Heils Franken. A gene in Cambrinus for resistance to PSH-10 and a gene in Mazurka for resistance to PSH-20 were dominant on the basis of the response of the first seedling leaf but recessive on the basis of the response of the second leaf. Four different types of epistasis were detected. Information on the number of genes, mode of inheritance, and nonallelic gene interactions should be useful in understanding the host-pathogen interaction and in breeding barley for resistance to stripe rust.  相似文献   

20.
我国地方品种是小麦白粉病抗性的重要来源之一,为了对地方品种抗源的利用奠定基础,采用常规杂交方法,以感病品种Chancellor分别与我国小麦抗病地方品种蚂蚱麦、小白冬麦、游白兰、红卷芒进行正交和反交,获得F1、F2代。根据白粉菌菌株的毒谱选用E09菌株对Chancellor与小白冬麦、游白兰、红卷芒的杂交后代进行苗期抗性鉴定和统计分析,选用E30菌株对Chancellor与蚂蚱麦的杂交后代进行苗期抗性鉴定和统计分析。结果表明4个品种在正、反交情况下均表现出由一对隐性基因控制的抗性,说明这4个地方品种属于核遗传,其抗性是由一对隐性基因控制的。  相似文献   

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