Analysis of sugarcane mosaic virus resistance in maize in an isogenic dihybrid crossing scheme and implications for breeding potyvirus-resistant maize hybrids

Genome ◽  
2006 ◽  
Vol 49 (10) ◽  
pp. 1274-1282 ◽  
Author(s):  
Yongzhong Xing ◽  
Christina Ingvardsen ◽  
Raphael Salomon ◽  
Thomas Lübberstedt

The gene action of 2 sugarcane mosaic virus (SCMV) resistance loci in maize, Scmv1 and Scmv2, was evaluated for potyvirus resistance in an isogenic background. All 4 homozygous and 5 heterozygous isogenic genotypes were produced for introgressions of the resistant donor (FAP1360A) alleles at both loci into the susceptible parent (F7) genetic background using simple sequence repeat markers. For SCMV and maize dwarf mosaic virus (MDMV), virus symptoms appeared rapidly in the 3 homozygous genotypes, with susceptibility alleles fixed at 1 or both loci. Although the 9 isogenic genotypes revealed a high level of resistance to Zea mosaic virus (ZeMV), the same 3 homozygous genotypes were only partially resistant. This indicates that 1 resistance gene alone is not sufficient for complete resistance against SCMV, MDMV, and ZeMV. Scmv1 showed strong early and complete dominant gene action to SCMV, but it gradually became partially dominant. Scmv2 was not detected at the beginning, showing dominant gene action initially and additive gene action at later stages. Both genes interacted epistatically (for a high level of resistance, at least 1 resistance allele at each of both loci is required). This implies that double heterozygotes at the 2 loci are promising for producing SCMVresistant hybrids. Results are discussed with respect to prospects for isolation of SCMV and MDMV resistance genes.

1981 ◽  
Vol 32 (5) ◽  
pp. 741 ◽  
Author(s):  
DM Persley ◽  
IF Martin ◽  
RS Greber

Maize inbred lines, derived from both Australian and exotic sources, and used in a breeding programme at Kairi, Qld, were screened for resistance to a Johnson grass strain of sugarcane mosaic virus (SCMV-Jg). There was a good correlation between ratings made following manual inoculation in a glasshouse and those following exposure to natural field infection. Seven lines were highly resistant in both glasshouse and field ratings. A further nine lines showed an intermediate level of resistance following manual inoculation and developed from 0 to 7 % infection under field conditions when a susceptible line developed 99 % infection. Data obtained following the manual inoculation of plants in segregating generations of crosses between resistant KL 57 and susceptible KL 9 were consistent with resistance being controlled by a single dominant gene. Six lines (Pa 405, CI 44, Tx 601, Oh 07, Oh 7B, 38-11) that were used as sources of resistance to maize dwarf mosaic virus, strain A (MDMV-A) in the U.S.A. developed natural infection levels of less than 15% with SCMV-Jg. Only Pa 405 was highly resistant to manual inoculation. Four of 11 SCMV-Jg resistant lines were also highly resistant to manual inoculations with the sugarcane, Sabi grass and Queensland blue couch grass strains.


2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 542-544
Author(s):  
R. Pokorný ◽  
M. Porubová

Under greenhouse conditions 12 maize hybrids derived from crosses of four resistant lines with several lines of different level of susceptibility were evaluated for resistance to Czech isolate of Sugarcane mosaic virus (SCMV). These hybrids were not fully resistant to isolate of SCMV, but the symptoms on their newly growing leaves usually developed 1 to 3 weeks later in comparison with particular susceptible line, the course of infection was significantly slower and rate of infection lower. As for mechanisms of resistance, the presence of SCMV was detected by ELISA in inoculated leaves both of resistant and susceptible lines, but virus was detected 7 days later in resistant line. Systemic infection developed only in susceptible lines. These results indicate restriction of viral long distance movement in the resistant line.


2011 ◽  
Vol 46 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Marcos Cesar Gonçalves ◽  
Diogo Manzano Galdeano ◽  
Ivan de Godoy Maia ◽  
César Martins Chagas

O objetivo deste trabalho foi caracterizar biológica e molecularmente três isolados de Sugarcane mosaic virus (SCMV) de lavouras de milho, analisá-los filogeneticamente e discriminar polimorfismos do genoma. Plantas com sintomas de mosaico e nanismo foram coletadas em lavouras de milho, no Estado de São Paulo e no Município de Rio Verde, GO, e seus extratos foliares foram inoculados em plantas indicadoras e submetidos à análise sorológica com antissoros contra o SCMV, contra o Maize dwarf mosaic virus (MDMV) e contra o Johnsongrass mosaic virus (JGMV). Mudas de sorgo 'Rio' e 'TX 2786' apresentaram sintomas de mosaico após a inoculação dos três isolados, e o DAS-ELISA confirmou a infecção pelo SCMV. O RNA total foi extraído e usado para amplificação por transcriptase reversa seguida de reação em cadeia de polimerase (RT-PCR). Fragmentos específicos foram amplificados, submetidos à análise por polimorfismo de comprimento de fragmento de restrição (RFLP) e sequenciados. Foi possível discriminar os genótipos de SCMV isolados de milho de outros isolados brasileiros do vírus. Alinhamentos múltiplos e análises dos perfis filogenéticos corroboram esses dados e mostram diversidade nas sequências de nucleotídeos que codificam para a proteína capsidial, o que explica o agrupamento separado desses isolados e sugere sua classificação como estirpes distintas, em lugar de simples isolados geográficos.


1980 ◽  
Vol 95 (3) ◽  
pp. 619-630 ◽  
Author(s):  
N. L. Innes ◽  
D. G. A. Walkey

SUMMARYA high level of resistance to the bean common mosaic virus strains NL3 and NL4 when inoculated separately or together was confirmed in the cultivars Turkish Brown, Valja and 1750–73. Following crosses between the susceptible cv. The Prince and all three resistant cultivars, inoculation of F2 and F3 populations revealed that the cvs Turkish Brown and Valja each differed from The Prince in being homozygous for a major recessive gene conferring resistance to both NL3 and NL4. Homology tests indicated that the same gene was present in both Turkish Brown and Valja. Polygenes in Turkish Brown and Valja also appeared to confer some resistance to NL3, or environmental variation led to continuous distribution patterns in the F2's of resistant parents crossed with The Prince. Although a major recessive gene controlled resistance to NL3 in cv. 1750–73, it differed from that in the two other resistant cultivars. In addition, cv. 1750–73 carried a dominant gene determining reaction to the virus; probably the I gene originally found in Corbett Refugee. An attempt is made to relate these results to Drijfhout's (1978) gene-for-gene model. Using Drijfhout's gene nomenclature all the cultivars tested appear to carry the strain nonspecific gene bc-u. Further genetical tests will be necessary to determine with certainty which, if any, of Drijfhout's strain-specific resistant bc-genes are present in the three resistant cultivars studied here.


1994 ◽  
Vol 59 (3) ◽  
pp. 345-358 ◽  
Author(s):  
I. J. M. de Boer ◽  
T. H. E. Meuwissen ◽  
J. A. M. van Arendonk

AbstractDesigns testing clones in a closed nucleus, in which 1024 cows are tested each year, were compared for their additive genetic response to selection (genetic response) and their genetic superiority of female genotype(s) selected for commercial cloning (clonal response), using stochastic simulation. Clones were tested at the expense of dam or sire families, matings per dam (sire), or full-sibs per family. The reference design maximized the genetic response corrected for inbreeding in the absence of cloning. The trait considered was overall economic merit for milk production, which was simulated assuming an approximate infinitesimal model with both additive and dominant gene action. Bulls and cows eligible for breeding were selected on their animal model estimated additive genetic effect at either 15 or 27 months of age. Female genotypes eligible for commercial cloning were selected on their estimated total genetic effect at 27 months of age. All (fe)male full-sibs were available for selection. With only additive gene action, testing clones at the expense of sire families, matings per dam or full-sibs per family reduced genetic response, while it increased clonal response and inbreeding. Testing clones at the expense of dam families, however, added to both the genetic and clonal response without increasing inbreeding. When eight clones were tested at the expense of dam families, the genetic response and the final genetic level of commercially available cloned embryos were maximal. Accuracy of clonal selection equalled 0·83. With dominant gene action, however, testing two clones at the expense of dam families maximized the final genetic level of cloned embryos, irrespective of the level of inbreeding depression (accuracy of 0·72). Reliable commercial clone lines can be produced now and in future generations by testing clones at the expense of dam families.


2017 ◽  
Vol 7 (3) ◽  
pp. 155 ◽  
Author(s):  
Marlina Mustafa ◽  
Muhamad Syukur ◽  
Surjono Hadi Sutjahjo ◽  
Sobir .

<p>ABSTRACT<br />Hypocotyl and cotyledon are potentially used as effective morphological markers since they can be detected earlier. Information on inheritance of tomato hypocotyl and cotyledon was not available. The aims of this research was to study the inheritance of qualitative and quantitative characters of tomato hypocotyl and cotyledon. This research used six population, P1 green hypocotyl (IPB T64), P2 purple hypocotyl (IPB T3), F1, F1R, BCP1, BCP2, and F2. Analysis of qualitative characters used Mendelian and gene action of quantitative characters used joint scaling test. The results of Mendelian indicated that the character of hypocotyl color was controlled by two genes of dominant-recessive epistasis. The gene controlling purple color was dominant to the green color gene. Based on the F2 distribution test, hypocotyl length, cotyledon length and width were controlled by polygenes. There was no influence of maternal effect. The results of the joint scaling test showed gene action of hypocotyl length was controlled by additive gene with influence of additive-dominant epistasis. Length and width of the cotyledon were controlled by additive gene and influence of duplicate epistasis effect. All characters had high level of broad sense heritability and medium level of narrow sense heritability.<br />Keywords: cotyledone, gene action, heritability, hypocotyle, morphology marker.</p><p>ABSTRAK<br />Hipokotil dan kotiledon berpotensi untuk dijadikan sebagai marka morfologi yang efektif karena dapat dideteksi lebih dini. Informasi pola pewarisan karakter hipokotil dan kotiledon tomat belum banyak tersedia. Penelitian ini bertujuan untuk mempelajari pola pewarisan karakter kualitatif dan kuantitatif dari hipokotil dan kotiledon tomat sebagai marka morfologi pada tahap awal pertumbuhan tanaman. Penelitian ini menggunakan enam set populasi yaitu P1 hipokotil hijau (IPB T64), P2 hipokoti ungu (IPB T3), F1, F1R, BCP1, BCP2, dan F2. Karakter kualitatif menggunakan analisis Mendel dan pendugaan aksi gen karakter kuantitatif menggunakan analisis skala gabungan. Hasil analisis Mendel menunjukkan bahwa karakter warna hipokotil dikendalikan oleh dua pasang gen epistasis dominan-resesif. Gen pengendali warna ungu bersifat dominan terhadap warna hijau pada hipokotil tomat. Panjang hipokotil, panjang dan lebar kotiledon dikendalikan oleh banyak gen dan tidak ada pengaruh tetua betina berdasarkan uji sebaran populai F2. Hasil analisis skala gabungan menunjukkan bahwa aksi gen karakter panjang hipokotil dikendalikan oleh gen aditif dengan pengaruh epistasis aditif dominan, panjang dan lebar kotiledon dikendalikan oleh gen dominan dengan pengaruh epistasis duplikat. Semua karakter yang diamati memiliki nilai heritabilitas arti luas dalam tingkatan yang tinggi, sedangkan heritabilitas arti sempit dalam tingkatan yang sedang.<br />Kata kunci: aksi gen, heritabilitas, hipikotil, kotiledon, marka morfologi.</p>


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1172e-1172
Author(s):  
J. H. M. Barten ◽  
J. W. Scott ◽  
J. Elkind ◽  
N. Kedar

A half diallel including 11 parents was conducted under high temp. conditions in Florida and low temp. conditions in Israel. Blossom scar (BS) size was measured relative to the fruit size for 20 mature fruits per plot. Griffing's analysis showed that both GCA and SCA effects were highly significant at both locations (p< 0.0001). Analysis according to Hayman indicated no epistatic effects. In both environments, additive and dominant gene action was significant (p < 0.0005), although the additive gene effects were most important. Averaged over all loci, the incomplete dominance was in the direction of small BS. Narrow sense heritability estimates were 0.62 and 0.57 for Florida and Israel, respectively. Combined analysis showed that the genetic system was unstable over the 2 environments, as both additive and dominant gene effects interacted significantly with environment (p < 0.0001). The implication for breeding programs is that hybrid performance should be tested at several locations to insure stability of small BS.


2017 ◽  
Vol 9 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Suprapto Suprapto ◽  
Narimah Md Kairudin

Information on genetic variation, heritability, gene action and genetic advance were important in the development of soybean varieties adapted on Ultisol. The objective of this experiment was to estimate genetic variation, hertability, gene action and genetic advance from the populaton used in breeding program. Six genotypes, i.e Dempo, Cikuray, Davros, Orba, Sindoro and Wilis were intercrossed using diallel Griffings’ Method 2 Model 1 (1956). These six genotypes and 15 F1  hybrids were planted on Ultisol using randomized complete block design with three replications located in Medan Baru village, Bengkulu city in 1999. The results of this experiment revealed that all traits showed low to high genetic variation, high broadsense heritability, low to high narrowsense heritability and genetic advance. Date of flowering and root length were fully controlled by additive gene action, however harvest index was fully controlled by   negative dominant gene action and epistasis. Other traits were controlled by positive and negative partially dominant, and positive overdominant  genes. 


2001 ◽  
Vol 14 (5) ◽  
pp. 587-598 ◽  
Author(s):  
M. R. Hajimorad ◽  
J. H. Hill

Rsv1, a single dominant gene in soybean PI 96983, confers resistance to most strains of Soybean mosaic virus (SMV), including strain G2. The phenotypic response includes the lack of symptoms and virus recovery from mechanically inoculated leaves. To study the resistance mechanism, SMV-N (an isolate of strain G2) was introduced into PI 96983 by grafting. Hypersensitive response (HR)-like lesions occurred on the stems, petioles, and leaf veins, and virus was recovered from these lesions. The response demonstrated the cytological and histological characteristics of HR as well as elevated transcription of a soybean salicylic acid-inducible, pathogenesis-related (PR-1) protein gene. Mechanical inoculation of PI 96983 primary leaves with a high level of SMV-N virions caused no symptoms or up regulation of the PR-1 protein gene transcript. Furthermore, inoculation with infectious viral RNA did not alter the resistance phenotype. The data suggest that interaction of SMV-N with Rsv1 has the potential to induce an HR-like defense reaction. Rsv1-mediated resistance in the inoculated leaf, however, is HR-independent and operates after virion disassembly.


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