46 PNL Volume 16 1984
RESEARCH REPORTS
LINKAGE RELATIONS OF TENDRILLED ACACIA (tac) AND APULV1NIC
Marx, G. A. NYS Agricultural Experiment Station, Geneva, NY USA
Two excellent seedling markers in peas have been isolated in recent
years. Evidence presented here indicates that both reside in chromo-
some 3.
The first, tendrilled acacia (tac), was described by Sharma
(3,4,5,6). The leaves of tac plants, like those of acacia (tl) plants,
terminate with a fully developed, laminar leaflet. Unlike tl, however,
tac plants have subterminal, tendril-like appendages (Fig. 1). The
mutant behaves as a single recessive but it shows some variability of
expression within the same plant and from plant-to-plant in segregating
populations. Nevertheless, classification of tac in segregating popula-
tions presents little difficulty, especially if scoring is delayed until
6 or 7 nodes have developed on seedling plants.
In 1979, Harvey (2) described a mutant which he provisionally named
apulvinic (Fig. 1). Appearing spontaneously in the cultivar 'Dark
Skinned Perfection', the mutant plants bear leaves in which all foliar
pulvini are replaced with rigid petiolules (2). It, too, is inherited
as a single recessive and can be scored unambiguously in the early
seedling stage. Its phenotype resembles a mutant designated by Blixt
(personal communication) as petiolulatus but apparently the identity
between the two has not been established. Until this matter is settled,
I shall refer to the Harvey mutant as apulvinic, with apu as the
provisional gene symbol.
Fig. 1. Top: (left) Tac Apu Fig. 2. af tac Note small
(right) Tac apu laminar leaflets amid
Bottom: (left) tac Apu otherwise tendrilled leaflets.
(right) tac apu
