PNL Volume 20                       1988 RESEARCH REPORTS                      39
Uzhintseva, L. P. and K. K. Sidorova Inst, of Cytology & Genetics USSA Academy of Sciences, Siberian Div., Novosibirsk, USSR
Early flowering pea mutants (Table 1), which differ from the initial variety in a low node of the first flower, date of flowering, and length of the vegetative period, were induced by gamma rays (mutant 2), EMS (398, 400, 418, 578), NEU (319, 320, 320/1, 326), or NMU (629). In all mutants except 319, 320, and 326 a low node of flower initiation correlates with early flowering as well as early ripening. Two mutants (2 and 400) have a shorter vegetative period but higher seed productivity than their initial varieties. Further details are given elsewhere (4,5).
Table 1. Initial variety and early flowering pea mutants. ___
Node of 1st flower
Mutant number
1st flower at nodes 5-7 (Group I)
1st flower at nodes 8-9 (Group II)
Torsdag Falensky 42 Parvus Saratovsky mestniy 231
11-13 12-15 11-13
2, 578
319, 320, 320/1, 326 400
In crosses with initial varieties and between themselves, in order to determine their allelism, all mutants appeared to be monogenic recessive mutations and to result from the mutation of different alleles of one locus (5). The Lf locus is indicated since Murfet (3) has identtified cultivar 'Torsdag' as Lf and mutants 2 and 519 as 1fa and lf, respectively. This conclusion was confirmed by several crosses. A cross between mutant 2 and marker line NGB1238 segregated in a monohybrid ratio for node of the first flower and the flowering gene showed linkage with marker A on chromosome 1. The Lf locus shows close Linkage with the A locus (1,6). In addition, the mutants were crossed with the type lines for lfa (Hobart line 7) and lf (Hobart line 58 = Nordic Gone Bank line 1792). The mutants were also crossed with Hobart lines 59 (lf) and 64 (lf), Vasileva's mutant XVIII/17 (obtained from the variety 'Wesna'), Wellensiek's M and E mutants (obtained from the variety 'Dominant', and Gottschalk's mutant 46C obtained from the variety 'Dippes Gelbe Vik-toria'). The last three mutant lines were formed by mutatiions of the type Lfd to Lf, Lfd to lf, and Lf to lfa, respectively (2). The results of the crosses indicated that all the mutants and lines studied are alle­lic and appear to be the result of mutations at the Lf locus; Group I mutants (2, 578, 398, 629, 418) have genotype lfa and Group II mutants (319, 320, 320/1, 326, 400) have genotype lf. Under Siberian conditions mutants XVIII/17, 46C, and Hobart line 7 formed their first flower at nodes 5-7, mutant E and Hobart lines 58 (NGB1792), 59, and 64 flowered at nodes 8-9, and mutant M at nodes 1114. All node counts commenced from the first foliage leaf as node 1. Thus under Siberian conditions the four
alleles lfd, Lf, lf, and lfa lead to the first flower forming at nodes 18-20, 11-14, 8-9, and 5-7, respectively.
We thank Dr. S. Blixt, Professor W. Gottschalk, Dr. I. C. Murfet, Dr. M. Vasileva, and Professor S. J. Wellensiek for providing mutants and lines.
40                          PNL Volume 20                      1988 RESEARCH REPORTS
1.   Hoshino, Y. 1915. J. Coll. Agric. Hokkaido Imp. Univ. 6:229-288.
2.   Murfet, I. C. 1978. PNL 10:48-52.
3.   Murfet, I. C. 1982. In Documentation of Genetic Resources: A Model. Eds. S. Blixt and J. T. Williams. IBPGR, Rome. pp. 45-51.
4.   Sidorova, K. K., V. V. Khvostova, and L. P. Uzhintseva. 1974. PNL 6:47.
5.   Uzhintseva, L. P. and K. K. Sidorova. 1979. Genetika 15:1076-1082.
6.   White, 0. E. 1917. Proc. Am. Phil. Soc. 56:487-589.