INHERITANCE OF THE DARK GREEN SEEDCOAT COLOR IN GARDEN PEAS

PNL Volume 15

1983

RESEARCH REPORTS

Baumunk-Wende, E.

Federal Research Centre for Horticultural

Plant Breeding, Ahrensburg

Federal Republic of Germany

I pointed out in 19 80 ( 3) that further genetical analyses of seed-

coat characters in garden peas would be desirable in order to establish

whether a new gene is responsible for the determination of the seed coat

color. Reciprocal crosses were made between cultivars with white and

dark green seedcoats. The results indicated a 3:1 monohybrid segrega-

tion, which other authors may have failed to recognize because the

seedcoat is maternal tissue and is determined by the maternal genotype.

The seedcoat is white (or light green) if the female parent has a white

(or light green) seedcoat and it is dark green if the maternal seedcoat

is dark green. Although the segregation of the cotyledon character is

distinguishable within one pod, the seedcoat color is not.

Our genetic analyses led us to believe that we were working with a

new gene for testa color. Then, however, we conducted identity tests

with two lines from the Weibullsholm collection (WL 2133 and WL 1395)

and with the cultivars 'Esmeralda' and 'Sublima' (our new variety with

dark green seedcoat). WL 2133 is homozygous for the gene .dp first

described by Marx (2) and WL 1395 is homozygous for gla first described

by Lamprecht (1). WL 1395 has a white seedcoat. Crosses between

WL 1395 and Esmeralda (with a white seedcoat) produced peas with white

or light green seedcoats in all progenies. Segregation for testa color

in progenies of the crosses "light green ♀(female) x dark green ♂(male) ", "dark

green ♀(female) x dark green ♂(male) " and their reciprocals are given in Table 1.

The results show agreement between observed and expected values. The

complementary test with the recessive factor (dark green x dark

green ) showed no segregation for light seedcoat colors. There were

no differences between WL 2133 and Sublima. This indicates that the

dark seedcoat color is part of range of characteristics covered by the

action or dp. Therefore the description for dp, viz. deep green pod

color, should be modified and extended to include its effect on seedcoat

color.

1. Lamprecht, H. 1959. Agri Hort. Genet. 17:1-8.

2. Marx, G. A. 1970. PNL 2:19-

3. Wende, E. 1980. PNL 12:74.

Editor's Note

It appears that the author of the above article expended con-

siderable time and effort needlessly simply because the gene

description for gene .d_p. is incomplete. I am personally responsi-

ble for this negligence and, quite likely, for other incomplete

or misleading descriptions as well. In my 1970 article

(PNL 2:19), I mentioned the effect of dp on flower, pod, and seed

color, but the gene description (PNL 10:88, 1978) mentions only

the effect on pods. This example illustrates the need for accur-

ate and complete descriptions. We hope that Pisum workers will

bring such faulty gene descriptions to our attention so that cor-

rective actions can be taken.