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1.
Summary The oat line Pc54 was found to be resistant to powdery mildew under both field and glasshouse conditions. The ratio of resistant to susceptible F2 and F2 progeny of a cross between a selection from the Pc54 line (Cc7422) and a susceptible cultivar (Selma) showed that, in addition to carrying the crown rust resistance gene Pc54 and the pg15 gene for stem rust resistance, the mildew resistance of the Pc54 line was conditioned by a single incompletely dominant gene along with additional factors which modified the expression of resistance. Previous results, that there was no linkage between genes Pc54 and Pg15, were confirmed. In addition, there was no evidence of linkage between the mildew resistance gene and gene Pc54. Evaluation of selections from within the Pc54 line showed that the expression of both stem rust and mildew resistance was modified by, or linked to, plant height. The effectiveness of genes Pc54 and Pg15, as measured by virulence frequencies, in central and eastern Europe is described. 相似文献
2.
Summary Hexaploid and octoploid tritordeums and their parents Hordeum chilense and Triticum spp. were screened for resistance to isolates of wheat and barley yellow and brown rusts. All H. chilense lines were highly resistant to both wheat and barley brown rust, few lines were susceptible to wheat yellow rust while susceptibility to barley yellow rust was common. In general the resistance of tritordeum is predominantly contributed by the wheat parent and apparently the genes for resistance in H. chilense are inhibited in their expression by the presence of the wheat genome.Abbreviations WYR
wheat yellow rust
- WBR
wheat brown rust
- BYR
barley yellow rust
- BBR
barley brown rust 相似文献
3.
A series of half-diallel crosses involving early, medium and late maturity desi and kabuli type chickpea (Cicer arietinum L.) genotypes with stable resistance to Helicoverpa pod borer, along with the parents, were evaluated at two locations in India to understand the inheritance of pod borer resistance
and grain yield. Inheritance of resistance to pod borer and grain yield was different in desi and kabuli types. In desi type chickpea, the additive component of genetic variance was important in early maturity and dominance component was predominant
in medium maturity group, while in the late maturity group, additive as well as dominance components were equally important
in the inheritance of pod borer resistance. Both dominant and recessive genes conferring pod borer resistance seemed equally
frequent in the desi type parental lines of medium maturity group. However, dominant genes were in overall excess in the parents of early and
late maturity groups. In the kabuli medium maturity group, parents appeared to be genetically similar, possibly due to dispersion of genes conferring pod borer
resistance and susceptibility, while their F1s were significantly different for pod borer damage. The association of genes conferring pod borer resistance and susceptibility
in the parents could be attributed to the similarity of parents as well as their F1s for pod borer damage in kabuli early and late maturity groups. Grain yield was predominantly under the control of dominant gene action irrespective of the
maturity groups in desi chickpea. In all the maturity groups, dominant and recessive genes were in equal frequency among the desi parental lines. Dominant genes, which tend to increase or decrease grain yield are more or less present in equal frequency
in parents of the early maturity group, while in medium and late maturity groups, they were comparatively in unequal frequency
in desi type. Unlike in desi chickpea, differential patterns of genetic components were observed in kabuli chickpea. While the dominant genetic component was important in early and late maturity group, additive gene action was involved
in the inheritance of grain yield in medium duration group in kabuli chickpea. The dominant and recessive genes controlling grain yield are asymmetrically distributed in early and medium maturity
groups in kabuli chickpea. The implications of the inheritance pattern of pod borer resistance and grain yield are discussed in the context
of strategies to enhance pod borer resistance and grain yield in desi and kabuli chickpea cultivars. 相似文献
4.
Genetic studies were undertaken to determine the number and identities of leaf rust resistance genes in common wheat lines
Agra Local and IWP94. The infection type arrays of the two lines with eight pathotypes (pt.) of P. triticina were different from those of lines possessing known leaf rust resistance (Lr) genes. Agra Local possessed two recessive resistance genes, one conditioning resistance to pathotype 4R9-7, and the other,
a temperature-sensitive factor, gave resistance to pt. 121R127 at high temperature (27°C). IWP94 was previously demonstrated
to carry Lr23. From the present study IWP94 was determined to have at least four leaf rust resistance genes. The first of these was the
same recessive gene conferring resistance to pathotype 4R9-7 which was found in Agra Local. A second partially dominant gene
conferred resistance to pathotype 121R127 at high temperature and two additional recessive genes governed resistance to pathotype
93R15. When present together, these two recessive genes complemented each other and provided resistance to pathotype 69R13
as well. One of the two recessive genes conferring resistance to pathotypes 93R15 and 69R13 was Lr23. 相似文献
5.
Three recombinant inbred line populations from the crosses RL6071/Thatcher, RL6071/RL6058 (Thatcher Lr34), and Thatcher/RL6058, were used to study the genetics of stem rust resistance in Thatcher and TcLr34. Segregation of stem
rust response in each population was used to determine the number of genes conferring resistance, as well as the effect of
the leaf rust resistance gene Lr34 on stem rust resistance. The relationship between resistance in seedling and adult plants was also examined, and an attempt
was made to identify microsatellite markers linked to genes that were effective in adult plants. In field plot tests at least
three additive resistance genes segregated in the RL6071/RL6058 population, whereas two resistance genes segregated in the
RL6071/Thatcher population. The presence of the gene Lr34 permitted the expression of additional stem rust resistance in Thatcher-derived lines both at the seedling and adult plant
stages. Seedling resistance to races TPMK and RKQQ was significantly associated with resistance in adult plants, whereas seedling
resistance to races QCCD and QCCB may have made a minor contribution. The seedling resistance genes Sr16 and Sr12 may have contributed to resistance in adult plants. A molecular marker linked to resistance in adult plants was identified
on chromosome 2BL. 相似文献
6.
Summary A set of 105 European wheat cultivars, comprising 68 cultivars with known seedling resistance genes and 37 cultivars that had not been tested previously, was tested for resistance to selected Australian pathotypes of P. triticina in seedling greenhouse tests and adult plant field tests. Only 4% of the cultivars were susceptible at all growth stages. Twelve cultivars lacked detectable seedling resistance to leaf rust, and among the remaining cultivars, 10 designated genes were present either singly or in combination. Lr13 was the most frequently detected gene, present in 67 cultivars, followed by the rye-derived gene Lr26, present in 19 cultivars. Other genes present were Lr1, Lr3a, Lr3ka, Lr10, Lr14a, Lr17b, Lr20 and Lr37. There was evidence for unidentified seedling resistance in addition to known resistance genes in 11 cultivars. Field tests with known pathotypes of P. triticina demonstrated that 57% of the cultivars carried adult plant resistance (APR) to P. triticina. The genetic identity of the APR is largely unknown. Genetic studies on selected cultivars with unidentified seedling resistances as well as all of those identified to carry APR are required to determine the number and inheritance of the genes involved, to determine their relationships with previously designated rust resistance genes, and to assess their potential value in breeding for resistance to leaf rust. 相似文献
7.
Summary In studies of the inheritance of resistance, pea seedlings of seven lines in which stems and leaves were both resistant to Mycosphaerella pinodes were crossed with a line in which they were both susceptible. With seven of the crosses resistance was dominant to susceptibility. When F2 progenies of five crosses were inoculated on either stems or leaves independently, phenotypes segregated in a ratio of 3 resistant: 1 susceptible indicating that a single dominant gene controlled resistance. F2 progenies of one other cross gave ratios with a better fit to 9 resistant: 7 susceptible indicating that two co-dominant genes controlled resistance. The F2 progeny of another cross segregated in complex ratios indicating multigene resistance.When resistant lines JI 97 and JI 1089 were crossed with a susceptible line and leaves and stems of each F2 plant were inoculated, resistance phenotypes segregated independently demonstrating that leaf and stem resistance were controlled by different genes. In two experiments where the F2 progeny of the cross JI 97×JI 1089 were tested for stem and leaf resistance separately, both characters segregated in a ratio of 15 resistant:1 susceptible indicating that these two resistant lines contain two non-allelic genes for stem resistance (designated Rmp1 and Rmp2) and two for leaf resistance (designated Rmp3 and Rmp4). Evidence that the gene for leaf resistance in JI 1089 is located in linkage group 4 of Pisum sativum is presented. 相似文献
8.
Summary Common and durum wheat populations obtained from Sweden and originally collected in Ethiopia were screened for resistance to steum rust and leaf rust. Resistant selections of common wheat were crossed and backcrossed with either stem rust susceptible RL6071, or leaf rust susceptible Thatcher. Genetic studies, based largely on tests of backcross F2 families, showed that four of the selections had in common a recessive gene SrA. Plants with this gene were resistant (1+ infection type) to all stem rust races tested. This gene was neither Sr26 nor Sr29. The resistance of other selections, based on tests with an array of rust isolates, was due to various combinations of Sr6, 8a, 9a, 9d, 9c, 11, 13, 30, and 36. One of the selections had linked genes, Lr19/Sr25. Another selection had a dominant gene for resistance (;1 infection type) to all the races of leaf rust. With the possible exception of this gene for leaf rust resistance and SrA, no obviously new resistance was found. 相似文献
9.
Evaluation of seedling and adult plant resistance to stem rust in European wheat cultivars 总被引：2，自引：0，他引：2
A total of 105 European wheat cultivars were assessed for seedling and adult plant resistance (APR) to stem rust using an
array of Australian isolates of Puccinia graminis f. sp. tritici. Twenty-seven cultivars were susceptible at both seedling and adult plant growth stages. Twelve catalogued seedling stem
rust resistance genes (Sr7b, Sr8a, Sr8b, Sr9b, Sr9g, Sr11, Sr15, Sr17, Sr29, Sr31, Sr36 and Sr38) were detected in the remaining cultivars, and 13 cultivars carried additional seedling resistance genes that could not be
postulated with the isolates used. Low levels of APR to stem rust were found in the cultivars Artaban, Forno, Mec, Mercia,
Pandas and Vlada. Although the genetic identity of this APR was not determined, it was clear that the only designated stem
rust APR gene Sr2 was not present in any of the cultivars tested based on the absence of the linked traits seedling chlorosis and pseudo black
chaff. One of these cultivars, Forno, is believed to carry the leaf rust APR gene Lr34, previously reported to be associated with improved resistance to stem rust. A detailed genetic characterisation of the APRs
in these cultivars will be needed to understand their modes of inheritance and relationships with catalogued stem rust resistance
genes. Such knowledge may help in developing cultivars with effective gene combinations that confer higher levels of protection. 相似文献
10.
The stripe (yellow) rust resistance gene Yr27 was located in wheat (Triticum aestivum L.) chromosome 2B and shown to be closely linked to the leaf (brown) rust resistance genes Lr13 and Lr23 in the proximal region of the short arm. Gene Yr27 was genetically independent of Lr16, which is distally located in the same arm. While Yr27 was often difficult to score in segregating seedling populations, it is apparently quite effective in conferring resistance to avirulent cultures under field conditions. The occurrence of Yr27 in Mexican wheat germplasm and the current over-dependence on Yr27 for crop protection in Asia are discussed. 相似文献
11.
Summary In former Czechoslovakia virulence of rusts attacking wheat was studied since the sixties. Since the same time genes for resistance in the registered cultivars were identified. The role of Berberis and Thalictrum as alternate hosts for stem rust and leaf rust, respectively, was investigated as well. Determined changes of virulence in rust populations could only partially be ascribed to changes of resistance genes in the grown cultivars. Unnecessary genes for virulence had no negative effect on the fitness of the pathogen. All tested samples of aeciospores from barberries attacked rye, not wheat. None of Thalictrum species occurring in the Czech and Slovak Republics was found to host wheat leaf rust. However, the sexual stage of wheat stem rust and wheat leaf rust could be induced on Berberis vulgaris and Thalictrum speciosissimum, respectively. General epidemiological conclusions are drawn from the results and experience of the last 35 years. 相似文献
12.
J. Šebesta 《Euphytica》1979,28(3):807-809
Summary In oat cv. Delphin (Bonda x Carstens Vii) two complementary genes were found conferring resistance to sixteen cultures of ten crown rust (Puccinia coronata
Cda. var. avenae
Fraser ET Led.) races. The complementary genes showed full dominance to eight races and incomplete dominance to two races. 相似文献
13.
A new resistance (R) gene to powdery mildew has been identified and characterized in a population derived from the wild potato species, Solanum neorossii under natural infection in the greenhouse. The segregation of resistance has revealed that this R gene is controlled by a single monogenic and dominant gene designated Rpm-nrs1. Analysis of the DNA sequence on an internal transcribed spacer (ITS) region of the pathogen genome suggests that the pathogen
causing the powdery mildew disease is either Golovinomyces orontii or G. cichoracearum. The resistance locus was localized to the short arm of chromosome 6 where several disease R genes already identified in potato and tomato are known to reside. The resistance locus cosegregated in 96 progeny with three
AFLP markers and one PCR marker. The sequences of the two cosegregating AFLP markers are highly homologous to Mi-1 conferring resistance to nematode, potato aphid and whitefly and Rpi-blb2 conferring resistance to late blight. The results in this study will facilitate the cloning of this gene conferring resistance
to powdery mildew. 相似文献
14.
Summary Sterile interspecific hybrids and colchicine-induced amphiploids of Zinnia elegans
Jacq. and Z. angustifolia HBK were examined to determine the mode of inheritance of resistance to Erysiphe cichoracearum DC ex Merat. Fertility was restored through colchicine treatment of two sterile hybrids of species reciprocal parentage which differed in ray petal response to the pathogen. Derived amphiploids were subsequently intercrossed to overcome the lack of segregation for this trait due to genetic control of pairing upon chromosome doubling. Resistance to E. cichoracearum appears to be complexly inherited in both leaves and ray florets of sterile hybrids and induced amphiploids. Two major dominant genes have been implicated in conferring resistance in ray petal tissue of derived amphiploids. Data obtained from the F1 hybrid progeny of the intercrossed amphiploids indicate that this trait is not cytoplasmically inherited. It is speculated that the genes conferring resistance in the ray florets are acting independently from those controlling leaf resistance and that most, if not all, of the resistance genes are inherited from Z. angustifolia.Scientific Article No. A-3825, Contribution No. 6804 of the Maryland Agricultural Experiment Station. 相似文献
15.
Barley genotypes Hor 1428, Hor 2926, Hor 3209, BBA 2890, Abyssinian 14, Grannelose Zweizeilige, and Stauffers Obersulzer are resistant to all races of Puccinia striiformis f. sp. hordei so far detected in the U.S.A. Heils Franken, Cambrinus, Astrix, Emir, Hiproly, Varunda, Trumpf,Mazurka, Bigo, BBA 2890, and I 5 are resistant to some races and susceptible to others. Previous studies showed that Hor 1428, Hor 2926, Hor 3209, Abyssinian 14, Stauffers Obersulzer, I 5, Heils Franken, Emir, Astrix, Hiproly, Varunda, and Trumpf each have two genes, and BBA 2890, Grannelose Zweizeilige, Cambrinus, Mazurka, Bigo, and BBA 809 each have a single genefor resistance. To determine the genes in specific genotypes and their relationships, all possible crosses were made among the 18 genotypes. Seedlings of parents and F2 progeny were tested under controlledconditions for resistance to selected races that were avirulent on both parents. Based on segregation within the individual crosses to selected races, at least 26 of 30 genes detected in the 18 genotypes were different. Allelic and linkage relationships of some of the genes were determined. The genetic information should be useful for understanding the host-pathogen interactions and for control of stripe rust using resistance. 相似文献
16.
Characterisation and origin of rust and powdery mildew resistance genes in VPM1 wheat 总被引：3，自引：0，他引：3
Summary The expression of rust resistances conferred by closely linked genes derived from VPM1 varied with environmental conditions and with genetic backgrounds. Under low light and low temperature conditions seedlings carrying Yr17 showed susceptible responses. Stem rust and leaf rust resistance genes Sr38 and Lr37 tended to confer more resistance at 17±2° C than at normal temperatures above > 20° C. These studies supported the hypothesis that Yr17, Lr37 and Sr38 were derived from Aegilops ventricosa, whereas Pm4b was probably derived from T. persicum. Studies on certain addition lines and parental stocks indicated that wheat cytoplasm may enhance the expression of Sr38. 相似文献
17.
António A. Monteiro Paula S. Coelho Kiril Bahcevandziev Luísa Valério 《Euphytica》2005,143(1-2):85-92
Parasitic nematodes damage white clover (Trifolium repens) roots, negatively impacting forage yield and persistence. No single gene resistance to nematodes has been identified in white clover. Trifolium semipilosum (2n = 2x = 16) genotypes exhibiting either complete resistance or susceptibility to infection by the clover root-knot nematode (CRKN), Meloidogyne trifoliophila, were identified. F1 progeny (n = 92) of a pair-cross between ‘TsR’, a plant heterozygous for the resistance phenotype and ‘TsS’, a plant homozygous for the susceptible phenotype, were challenged with infective CRKN juveniles and evaluated subsequently for root galling. Segregation analysis indicated the resistance phenotype may be conferred by a single dominant allele at a locus (designated TRKR, Trifolium Root-knot Resistance) subject to segregation distortion. TsR, TsS, and bulked resistant and bulked susceptible F1 progeny (n = 12/bulk) were screened using T. repens microsatellite (SSR) markers. Three SSRs revealed polymorphism in TsR and the resistant bulk, of which prs090 and prs247 map to loci on T. repens linkage group D2. Progeny were genotyped with these three SSRs and 23 additional SSRs from T. repens groups D1 and D2. Linkage analysis in both TsR and TsS demonstrated macro-synteny between T. repens group D homoeologues and the T. semipilosum linkage group (designated DTs) containing the TRKR locus. Significant segregation distortion was detected in TsR, and recombination in the central region of the T. semipilosum linkage group was suppressed relative to T. repens in both parents. These data demonstrate the opportunities and challenges for comparative mapping in Trifolium and characterisation of loci conferring resistance to plant-parasitic nematodes. 相似文献
18.
Summary Although wild oats (Avena fatua L.) have been considered a potential source of genes for cultivated oat (Avena sativa L.) improvement, most progenies of A. sativa/A. fatua crosses have weak straw and are very susceptible to crown rust (Puccinia coronata CDA. var. avenae Fraser and Led.). Backcrossing to A. sativa has been suggested as a method of improving progeny lines while introducing new genes from wild oats to cultivated oats. In this study, A. sativa/A. fatua F1 hybrids were backcrossed twice to A. sativa, and lines from three backcross populations were selected on the basis of agronomic performance in segregating generations. The A. sativa recurrent parents were Dal (tall and late) and Stout (short and early).Backcross lines and recurrent parents were evaluated in five performance trails from 1983 through 1985. There was significant variation among backcross lines for most traits, but most backcross lines did not produce higher grain and straw yields than their A. sativa parent. Several backcross lines were higher than their recurrent parent in test weight and groat percentage. A line derived from Stout, 175BC2-6, was considered the most promising backcross line in the study. This line produced more grain, had heavier kernels, and headed 3.3 days earlier than Stout. Although 175BC2-6 does not have sufficient straw strength and crown rust resistance to be released as a cultivar, it is considered to be a new source of high grain yield, high test weight and earliness for oat breeding. 相似文献
19.
In this study, we characterized the genetic resistance of the Andean bean cultivars Kaboon and Perry Marrow and their relation
to other sources of anthracnose resistance in common bean. Based on the segregation ratio (3R:1S) observed in two F2 populations we demonstrated that Kaboon carries one major dominant gene conferring resistance to races 7 and 73 of Colletotrichum lindemuthianum. This gene in Kaboon is independent from the Co-2 gene and is an allele of the Co-1 gene present in Michigan Dark Red Kidney (MDRK) cultivar. Therefore, we propose the symbol CO-1
2 for the major dominant gene in Kaboon. The Co-1 is the only gene of Andean origin among the Co anthracnose resistance genes characterized in common bean. When inoculated with the less virulent Andean race 5, the segregation
ratio in the F2 progeny of Cardinal and Kaboon was 57R:7S (p = 0.38). These data indicate that Kaboon must possess other weaker dominant resistance genes with a complementary mode of
action, since Cardinal is not known to possess genes for anthracnose resistance. Perry Marrow, a second Andean cultivar with
resistance to a different group of races, was shown to possess another resistant allele at the Co-1 locus and the gene symbol Co-1
3 was assigned. In R × R crosses between Perry Marrow and MDRK or Kaboon, no susceptible F2 plants were found when inoculated with race 73. These findings support the presence of a multiple allelic series at the Andean
Co-1 locus, and have major implications in breeding for durable anthracnose resistance in common bean.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
Summary Genetic regulation of host resistance in chickpea-Ascochyta rabiei interaction system is governed by two dominant complementary genes each in the genotypes GLG 84038 and GL 84099, whereas the resistance in a black seeded genotype ICC 1468 was controlled by one dominant and one recessive independent gene. In all the genotypes, resistance is operated by inter-allelic interactions. The genes conferring resistance in GLG 84038 were found to be different to those operating in GL 84099 and ICC 1468. Among the five dominant genes dispersed in 3 genotypes under study, at least one has been reported for the first time, as to date, only three dominant genes have been reported in the literature.The four identified dominant genes in GLG 84038 and GL 84099 have been named as Arc1, Arc2 (in GLG 84038) and Arc3, Arc4 (in GL 84099). The undistinguished dominant gene in ICC 1468 has been named as Arc5(3,4) as it could not be equated or differentiated from Arc3 or Arc4. The recessive gene in ICC 1468 has been named as Arc1.Generation mean analysis of the 6 resistant × susceptible crosses involving the same genotypes, revealed that the genes conferring resistance in any of the 3 genotypes did not follow simple Mendelian inheritance but were influenced by inter allelic interactions. Additive gene effect along with dominance were operative in all the 3 genotypes under study in conferring resistance. However, the mechanism of resistance in GLG 84038 and GL 84099 were primarily additive in nature while that in ICC 1468, dominance as well as dominance × dominance interactions were more important than additive gene action. 相似文献