GrainGenes
A Database for Triticeae and Avena
strain of the Barley Yellow Mosaic Virus Complex
J. Weyen, F. Ordon and W. Friedt
Institute of Crop Science and Plant Breeding I, Justus-Liebig-University,
Ludwigstr. 23, D-35390 Giessen, Germany
In order to obtain first information on the mode of inheritance of resistance to BaYMV-2, F3-progenies of crosses between resistant exotic germplasms, i.e. ´Mokusekko 3´, ´Ou 1´, ´Ou 4´, ´Russia 57´, ´Taihoku A´ and BaYMV-2 susceptible cultivars (´Magie´, ´Trixi´, ´Ogra´, ´Alraune´, ´Copia´ and ´Maksimirski 452´) as well as an intercross of resistant germplasms, i.e. ´Mokusekko 3´, ´Ou 1´, were analyzed in a field at Schladen (Lower-Saxony) uniformly infested with BaYMV-2. For this purpose 30 kernels of each F3-line were sown at Schladen in 1993/94 and 1994/95. Reaction to BaYMV-2 of plantlets in the tillering stage was scored visually as well as by DAS-ELISA using antiserum kindly provided by Dr. Huth, Federal Biological Research Centre, Braunschweig, Germany. It is rather difficult to differentiate homozygous susceptible lines from heterozygous susceptible lines in the field due to the fact that a unknown portion of the individual plants may have escaped infection. Therefore, lines as a whole were classified as resistant and susceptible only and X²-values were calculated on segregation ratios of 1r : 3s in the case of a single recessive gene instead of 1r : 2rs : 1s.
Tab. 1: F3-segregation analysis of crosses between exotic germplasm resistant against BaYMV-2 and BaYMV-2 susceptible German cultivars or exotic resistant germplasm, respectively
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Cross combination Segregation ratio X²-value P n
observed expect.
r:s r:s
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Mokusekko 3 x Magie 9:32 1:3 X²\(1:3)=0,0077 >0,9 41
Ou 1 x Mokusekko 3 110:0 - - >0,99 110
Ou 1 x Trixi 25:93 1:3 X²\(1:3)=0,914 0,2-0,5 118
Ou 4 x Ogra 30:37 7:9 X²\(7:9)=0,0286 0,5-0,9 67
(Russia 57 x 9:38 1:3 X²\(1:3)=0,85 0,2-0,5 47
Alraune) x Alraune
Russia 57 x Magie 15:58 1:3 X²\(1:3)=0,770 0,2-0,5 73
Taihoku A x Copia 46:99 1:3 X²\(1:3)=3,49 0,05-0,1 145
Taihoku A x Igri 9:27 1:3 X²\(1:3)=0 >0,99 36
Taihoku A x 29:54 1:3 X²\(1:3)=4,373 0,01-0,05 83
Maksimirski 452
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r = resistant, s = susceptible, P = probability,
n = number of lines analyzed
The results of these studies are presented in Table 1. In all crosses of
resistant varieties to susceptible cultivars, except the cross ´Ou 4´
x ´Ogra´, a good fit to a segregation ratio of 1r : 3s was observed
giving hint to a monogenic recessive mode of inheritance of BaYMV-2
resistance. The segregation ratio observed in the cross ´Ou 4´ x
´Ogra´ fit to a 7r : 9s ratio ((X²<3,841) expected in the case of a
digenic recessive mode of inheritance. Since no susceptible progeny were
observed in the cross ´Ou 1´ x ´Mokusekko 3´ it may be
concluded that BaYMV-2 resistance genes of these varieties are allelic. The
recessive mode of inheritance of BaYMV-2 resistance observed in F3-lines
has been confirmed in analyse of F1-plants out of crosses between
´Mokusekko3´, ´Russia 57´ and ´Ou 1´ to susceptible
German cultivars, where all crosses proved to be susceptible to BaYMV-2
(data not shown).The first results on the inheritance of BaYMV-2 reaction revealed that resistance to this virus like that to BaMMV (Götz & Friedt 1993, Ordon & Friedt 1993) is inherited recessively. However, due to the fact that BaYMV-2 - in contrast to BaMMV - is not efficiently mechanically transmissible, genetic analysis of resistance is much more difficult to achieve. Studies on the mechanical transmission of BaYMV-2 revealed that by modifying the method of Friedt (1983) infection rates sufficient for reliable testing DH-lines in the greenhouse can be achieved, i.e. testing 10-20 plants of each DH-line. DH-lines out of F1-plants of crosses between BaYMV-2 resistant exotic germplasms and susceptible German cultivars were produced by microspore culture (Prüfe 1995, pers. comm.) This material provides the opportunity to get detailled information on the mode of inheritance and on the question whether resistance to BaMMV, BaYMV and BaYMV-2 is due a single gene conferring resistance to all of the virus or to specific genes acting against a single virus. Furthermore, by using these DH-lines molecular markers for BaYMV-2 resistance may be identified just like in the case of BaMMV-resistance (Ordonet al.1995, Graner et al. 1996). Since BaYMV-2 is still extremely difficult to transmit mechanically marker assisted selection will be a very useful tool for practical barley breeding to incorporate resistance to BaYMV-2 into adapted cultivars. This approach is finally expected to save input in laboratory, space and time necessary for running a successful winter barley breeding programme.
Acknowledgements :
This research work was supported by the „Gemeinschaft zur Förderung der privaten deutschen Pflanzenzüchtung e.V." (GFP), Bonn (Grant No. G 59/93 HS-92).
References :
Beaton, D., 1989: "Resistant" varieties hit by BYMV strain. Farmers weekly 3, 42.
Foroughi-Wehr, B. and G. Wenzel, 1990: Recurrent selection alternating with haploid steps - a rapid breeding procedure for combining agronomic traits in inbreeders. Theor. Appl. Genet. 80, 564-568.
Friedt, W., B. Foroughi-Wehr and W. Huth, 1983: Züchtung auf Gelbmosaikvirusresistenz der Wintergerste. Vortr. Pflanzenzüchtg. 3, 169-179.
Friedt, W., F. Ordon, R. Götz und R. Kaiser, 1990: Bodenbürtige Krankheiten, eine fortdauernde Herausforderung für die Pflanzenzüchtung - beleuchtet am Beispiel der Gelbmosaikvirose der Gerste. Ber. Arbeitstag. Saatzuchtl. Gumpenstein 40, 27-38.
Götz, R. and W. Friedt, 1993: Resistance to the Barley Yellow Mosaic Virus Complex - Differential genotypic reactions and genetics of BaMMV-Resistance of Barley (Hordeum vulgare L.). Plant Breeding 111, 125-131.
Graner, A., E. Bauer, A. Kellermann, G. Proeseler, G. Wenzel and F. Ordon, 1996: RFLP-analysis of resistance to the Barley Yellow Mosaic Virus Complex. Agronomie (in press).
Huth, W., 1989: Ein weiterer Stamm des Barley Yellow Mosaic Virus (BaYMV) gefunden. Nachrichtenbl. Deut. Pflanzenschutzd. 41, 6-7.
Huth, W., 1990: The yellow mosaic inducing viruses of barley in Germany. Proc. 1st Symp. Intern. Working Group Plant Viruses with Fungal Vectors, Braunschweig, Germany, August 21-24, 113-115
Huth, W., 1991: Verbreitung der Gelbmosaikviren, BaYMV , BaMMV und BaYMV-2 und Screening von Gerstensorten auf Resistenz gegenüber BaYMV-2. Nachrichtenbl. Deut. Pflanzenschutzd. 43, 233-237.
Ordon, F. and W. Friedt, 1993: Mode of inheritance and genetic diversity of BaMMV resistance of exotic barley germplasms carrying genes different from ym4. Theor. Appl. Genet. 86, 229-233.
Ordon, F., R. Götz and W. Friedt, 1993: Genetic stocks to Barley Yellow Mosaic Viruses (BaMMV, BaYMV, BaYMV-2) in Germany. Barley Genetics Newsletter 22, 46-50.
Ordon, F., E. Bauer, K.J. Dehmer , A. Graner and W. Friedt, 1995: Identification of a RAPD-marker linked to the BaMMV/BaYMV resistance gene ym4. Barley Genetics Newsletter 24, 123-126.