Mutation air dots (adt) with slight unitac-like effect on the leaf

Gorel, F.L., Berdnikov, V.A. and                            Inst. of Cytology and Gen., Russian Acad. of Sci.

Kosterin, O.E.                                                                                                    Novosibirsk, Russia

 

      A recessive mutation adt was found in M2 plants after EMS treatment of seeds of the stock SG. Formally, this mutation can be classified as an aeromaculata type (1). The most distinct feature of adt mutants is the numerous tiny grey spots along veins of leaflets and stipules (Fig. 1). In addition to this trait there are many devia-tions from the normal phenotype. The coloration of wings is very similar to that of the standard (Fig. 2), the pods are shorter and wider, and the leaves often (but not always) look like the leaves of the unitac mutant (3) in that the terminal tendril are replaced by a leaflet (Fig 1). The mutant was used to produce an isogenic line AIR. Despite resemblance of our mutant to unitac plants, F1 plants from the cross with the line homozygous for unitac had wild-type phenotype, and the phenotype segregation pattern in F2 suggested the absence of tight linkage between uni and adt. The cross of the line AIR (i, R, Gp, u, Wb, K, S, Dw, Pl, m, St) with the tester line WL1518 (I, r, gp, Ust, wb, k, s, d, pl, M, st) gave evidence for a linkage with the locus M (Table 1). The relatively weak linkage to M and lack of linkage to St suggests that adt is located near the upper tip of LG III, although this conclusion should be considered as preliminary.

Подпись: Fig. 2. Dissected flowers of the stock SG plant, with the wild-type allele Adt (left), and an adt mutant (right) Подпись: Fig. 1. Leaf phenotypes in adt mutation in different genetic backgrounds (wild type, af and af tlw)

 

 

 

 

 

 

 

 

Table 1. Joint segregation data for the loci Adt, M and St at the linkage group III obtained in F2 of the cross AIR x WL1518.

 

locus A

locus B

A B

A b

a B

a b

N

Rec. fract.

St. error

J. seg. Chi-sq.

 

 

 

 

 

 

 

 

 

 

Adt

M

153

36

31

27

247

32.8

3.8

17.71

Adt

St

146

46

44

16

252

52.0

4.6

0.2

M

St

134

50

51

12

247

43.5

5.1

1.6

1 p<0.0001

      Like unitac, adt manifests some antagonism with afila. The leaves of triple homozygotes adt/adt af/af tl/tl found among F2 pants, after crossing AIR with the line homozygous for a, af, and tl, are not as strongly ramified as those of af tlw.  Rather the phenotype is more similar to that of unitac af tlw (Fig 1). We cannot exclude that Adt may be one of the X-factors with Uni-like function postulated by Hofer and Ellis (2).

 

 

 

Acknowledgement: This work was partly supported by the 'Russian Fund for Fundamental Research', grant No 02-04-494260.

 

 

1.   Blixt, S. 1972. Agri Hortique Genet. 30: 1-293

2.   Hofer, J, Ellis, T. J. M. 1998. Trends Plant Sci. 3: 439-444.

3.   Sharma, B. 1972. Pisum Newslett. 4: 50.