36                          PNL Volume 20                      1988 RESEARCH REPORTS
A THIRD COSTATA GENE (lum-3) ON CHROMOSOME 5
Swiecicki, W. K.                                   Plant Breeding Station, Wiatrowo, Poland
In earlier studies on mutations induced by combined doses of Nf + NEU (3) several costata mutation cases were found. Locus identity tests showed that three of them, Wt 15307, Wt 14303, Wt 15311 and Monti's gene lum-1 were controlled by different loci. Despite the same general phenotypic effect (i.e. normal green veins with lighter interveinal leal tissue) these mutants had different influences on seed yield (Fig.1) (2). The mutant in the accession Wt 15307 was designated as lum-2 and was mapped to chromosome 3 (4).
I then set out to localize lum-3 i.e. the gene controlling costata character in Wt 15309 (induced by seed treatment of cv. 'Paloma' using 200rNf + 0.014% NEU). Crosses with testerlines WL 851, WL 1143, WL 1288, and WL 1514 did not reveal linkage with A, i (Chr 1); k, wb, s, oh (Chr 2); b, st, M (Chr 3); n, fa, v (Chr 4); wlo, Pl (Chr 6); and tl, r (Chr 7). The F2 population from the cross Wt 15309 (costata) x WL 1238 (testerline) showed monogenic inheritance of lum-3 and most of the marker genes in chromosome 5 (Table 1A). Although the segregation patterns were strongly disturbed, overall the data suggest lum-3 is located in chromo­some 5 and I propose the following approximate relationship:
The type lines for lum-1, lum-2, and lum-3 are respectively WL 6011 (1), Wt 15307 (3), and Wt 15309.
1.   Monti, L. M.     1970. PNL 2:21-22.
2.   Swiecicki, W.   K. 1983. Hod. Ros. Akl. Nas. 27 (4):221-276.
3.   Swiecicki, W.   K. 1984. PNL 16:84-86.
4.   Swiecicki, W.   K. 1987. PNL 19:70-71.
PNI. Volume 20                       1988           RESEARCH REPORTS                      37
Table 1. Phenotypic distribution in an F2 population from a cross between Wt 15309 (costata) and WL 1238 (testerline).
A.
Monohybrid F2' segregation
Chi-square (3:1)
Lum-3 362
lum-3 122
Total 484
0.01
Cp
370
cp 49
419
39.56
Gp
374
gp 104
478
2.68
Te 314
te 105
419
0.00
B. Joint segregation of Lum-3 with Cp, Gp, and Te
Joint Chi-square
Recomb. fract.
S.E.
Cp Te 309
Cp te
53'.
cp Te 3
cp te 46
Total
411
145.1
8.5
1.45
Cp Gp
327
Cp gp
4 '.
cp Gp 3
CP 8P 46
419
183.7
7.5
1 .35
Cp Lum-3 260
Cp lurn-3 110
cp Lum-3 49
cp lum-3 1
419
20.1
15.1
4.75
Te Gp 308
Te gp
6
te Gp 16
te gp 88
418
312.8
4.9
1.09
Te Lum-3 210
le lum-3 104
te Lum-3 100
te lum-3 5
419
32.1
21.2
4.62
Gp Lum-3
255
Gp lum-3 1 l'l
gp Lum-3 103
gp lum-3 1
478
40.9
10.1
4.52
Fig. 1. Yield components and percent protein content for costata mutants in percent of initial line. I-Number of pods per plant; II-Number of seeds per pod; III-Seed yield/plant; IV-TGW; V-Percent protein.
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