60 RESEARCH REPORTS
PNL Volume 12
1980
FURTHER DATA ON THE ASSORTMENT OF THE sn LOCUS
Murfet, I.C, and C. Gillian
Botany Department, University of Tasmania, Hobart, Australia
Linkage tests covering most of the known linkage map failed to locate
the sn gene (2). However, the tests did raise the possibility of linkage
between sn and pl. Furthermore, the top end of group 7 was not covered in
the survey. In addition, Bereznicki and Reid (1) reported evidence of a
loose linkage between sn and the unlocated gene, es. These leads have now
been checked.
Additional data on the joint segregation of pl and sn have been
obtained from a further 110 plants of Cross 175 (L58 x Marx G) and 85
plants of Cross 235 (L58 x L66). These new results are combined in Table
1 with the previous data from (1). In addition, data on the joint
segregation of fl and sn were obtained from crosses 278 (L53 x L100), 295
(L60 x L100) and 286 (Weibullsholm line 360 fl Sn wsp Es x L59 Fl sn Wsp
es). In all, the results provide no statistical justification for
assuming anything other than free recombination between sn and markers pl
and fl but, on the other hand, the results do not entirely discount the
possibility that sn is located at the lower extremity of chromosome 6.
Cross 286 also provided data on the joint segregation of wsp, es and
sn. All three loci assorted independently in this cross.
In summary, after twenty years of study, the location of the
horticulturally important and academically interesting sn gene remains
unknown.
1. Bereznicki, W.C. and Reid, J.B. 1978. PNL 10:3-4.
2. Murfet, I.C. 1978. PNL 10:56.
