S.M. Rozov, F.L. Gorel, and V.A. Berdnikov.

Institute of Cytology and Genetics, Novosibirsk, 630090, RUSSIA

A new mutant was isolated from the M2 progeny of line Sprint-2, treated with 0.15% EMS. This mutant is characterised with a white stem and precocious yellowing of leaves, which begins at the stage of 8-10 nodes developed. The process of yellowing starts with the lower leaves and overtakes the whole plant shortly before maturity. Young pods just developed from the flowers are green, but very rapidly they become lime-yellow. This mutant was crossed with the line WL-2134, carrying gene py for precocious yellowing (1). The F1 plants were of normal phenotype, which shown the new mutant not to be allelic to py gene. We propose to rename the previously named by Marx (1) gene py into py-1 and to name the newly obtained mutant gene as py-2.

As was revealed by Marx, the gene py-1 is located near the gene gp in the V linkage group of pea (1). We crossed the line WL-2134 (py-1) with our tester-line RT-9, carrying eight markers for V linkage group. The results of segregation in F2 are shown in Table 1.

The position of py-1 gene in the linkage group V of the pea, as it follows from the perfomed cross is shown on the following scheme:

The py-2 mutant line was crossed with the tester WL-2224. An obvious linkage of py-2 was observed in F2 progeny of this cross with the genes i and af of the i segment of pea linkage map:

Unfortunately, there were no possibility to establish the order of the genes involved in this cross due to relatively small F2 population and a repulsion phase of py-2 and marker genes.

This work was partially supported by the Russian State Program for Fundamental Research.

References:

1. Marx G.A. 1971, PNL, v.3, p.20