Linkage analysis of high pI esterase isozyme Est11 in barley
Linkage analysis of high pI esterase isozyme Est11 in barley
Tomohiro Ban and Naoyuki Kawada*
Kyushu National Agricultural Experiment Station, MAFF,
Chikugo, Fukuoka, 833 Japan

*Present address: Tochigi Agricultural Experiment Station, Tochigi, 328 Japan

Using isoelectric focusing (IEF) in polyacrylamide gel, new allels at Est9 locus and new loci Est11 for leaf esterase isozyme of barley were detected at high pI over 8.0 (Ban and Kawada 1989, 1990). Through the survey of zymograms'of 340 accessions, it was confirmed that Est11 locus related with V/v locus located on chromosome 2. In this study, we report genetic variation and linkage analysis of the high pI esterase isozyme in barley.

The materials for linkage analysis consisted F2 individuals derived from a cross Ishuku-shirazu x OUL064, which was a linkage stock containing multiple markers located on the chromosome 2: namely, e (wide outer glume), gs9 (glossy sheath and ear), V (two-rowed) and li (ligule-less). Genotypes of esterase isozyme were investigated by IEF method (Ban and Kawada 1989), using the first leaf of each 7-day-old seedling grown in a chamber controlled 12-h illumination at 20°C.

Using IEF in the gel forming pH 5 to 10.5 gradient, reproducible 16 bands of esterase isozyme were detected. The zymogram pattems of them were divided into 19 types in 340 barley accessions examined (Fig. 1). Hivid and Nielsen (1977) demonstrated that two alleles, Fl and ne, at Est9 locus controled the isozyme band appeared on the cathodal side of the starch gel, and Yoshimi and Konish (1994) found a variant allele in a strain of H. spontaneum, Spont. 6908 (OUH614). We found variant alleles at Est9 locis controling pI 8.3 and pI 8.6 bands respectively. These were designated as Mi for Misato Golden and Ou for OUL064.

We also found that the Est11 locus carried at least two alleles designated Yo for Yokozuna and Cl for Claret. Yo allele controlled a strong band at pH 8.1, and no Japanese tow-rowed variety possessed this band. On the other hand, Cl allele expressed three strong bands and a faint band with pI 8.4 to 8.6, which formation had never been broken through the allelism test. As shown in Table 1, the isozyme acne at Est11 was linked with three marker genes located on chromosome, ie. li, V and gs9. The arrangement of the genes on the chromosome 2 is shown in Fig. 2. Komatsudaet al. (1993) used the Est11 locus to map Shd1 locus on chromosome 2L and also reported that the Est11 locus linked with V locus, which recombination value was 24.8%. Netsvetaev (1992) reported that Est12 locus controlling esterase band in the lowest mobility in PAGE was located on chromosome 2 linked with the V locus. As the result of our linkage analysis, it is concluded that the Est12 locus is identical Est11, hence, another locus linked with Ble and al on chromosome 3 (Netsvetaev 1991) should be designated as Est12.

References:

Ban, T. and N. Kawada. 1989. Barley esterase isoenzyme variants separated by isoelectric focusing methods. Japan. J. Breed. 39, supl. 2: 144-145. (In Japanese)

Ban, T. and N. Kawada. 1990. Genetic variation and genetic analysis of high pI barley esterase isoenzyme. Japan. J. Breed. 40, supl. 2: 282-283. (In Japanese)

Hivid, S. and G. Nielsen. 1977. Esterase isoenzyme variants in barley. Hereditas 87: 155-162.

Komatsuda, T., T. Annaka and S. Oka. 1993. Genetic mapping of quantitative trait locus (QTL) that enhances the shoot differentiation rate in Hordeum vulgare L. Theor Appl Genet 86: 713-720.

Netsvetaev, V. P. 1991. Linkage of Hordeum spontaneum blue endosperm gene (Ble) and two esterase loci (Est4, Est11) with marker genes on barley chromosome 3. Barley Genet. Newl. 21: 60-63.

Netsvetaev, V. P. 1992. Chromosomal location of loci Est12 and Amy2 in barley. Barley Genet. Newl. 22. 42-43.

Table 1. Segregation of isozyme gene at the Est11 locus and marker genes on the chromosome 2 in Ishuku-shirazu (Cl, +, +, V, +) x OUL064 (Yo, e, gs9, v, li) F2 popuration

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Gene pair              Segregation                     Recomb.
A      B   AAB_:AAbb:AaB_:Aabb:aaB_:aabb  Total  X²\L  value(%)
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Est11  e    72 : 23 : 132 : 49 : 80 : 43  399    5.3  indipendent
Est11  gs9  81 : 12 : 137 : 42 : 76 : 40  388   13.7  indipendent
Est11  V    88 :  7 : 140 : 41 : 50 : 73  399  104.9  25.5±2.47
Est11  li   88 :  9 : 156 : 33 : 58 : 78  422  112.1  25.4±2.40

               A_B_ : A_bb : aaB_ : aabb

e      gs9  281 : 10 : 25 : 91            407  270.3  8.8±1.5
e      V    244 : 56 : 50 : 73            423   89.3  26.4±2.6
e      li   226 : 73 : 89 : 32            420    0.2  indipendent
gs9    V    251 : 55 : 34 : 67            407   94.1  23.8±2.5
gs9    li   236 : 72 : 74 : 27            409    0.5  indipendent
V      li   235 : 57 : 80 : 48            420   17.4  37.9±3.14
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Fig. 2 Linkage relation of the Est11 and other marker genes on the chromosome 2.


Fig. 1 Zymogram patterns of high pI esterase isozyme of barley by isoelectric focusing PAGE method.

Nomenclature of alleles for esterase isozymes demonstrated in this figure is followed by Hivid and Nielsen (1977)

1. Claret, 2. Misato Golden, 3. Daisen Gold, 4. TN1, 5. Israel 46,

6. Hungarian 7. New ZZ, 8. Iran two-rowed 1, 9. Russian 74,

10. Indo-mugi, 11. Mihorihadaka 3 12. Yokozuna, 13. OUL064, 14. KUSE 5055,

15. Lico 1-7544, 16. Turkey 17. Nakao 1659, 18. Flynn,

19. H. spontaneum, Spont. 6908 (OUH614)