DESYNAPTIC ALLELIC PEA MUTANTS

14 RESEARCH REPORTS

PNL Volume 12 1980

Gostimski, S. A. and T. A. Ezhova Moscow State University, USSR

Two chlorophyll-mutant lines which were produced from treatment of

seeds with EI (line 9) and EMS (line 12) also were found to contain

meiotic mutations. These mutations seem to have arisen simultaneously with

the chlorophyll mutations in the initial cells, following mutagen treatment

of seeds.

Study of meiosis of meiotic mutants revealed that mutant genes in both

lines do not influence the process of conjugation of chromosomes in zygotene-

pachytene cells, but disturb chiasma formation, though to a different extent.

As a result of this disturbance, both mutant lines developed univalents in

the first metaphases, laggards at anaphases, high pollen sterility, and

slightly reduced seed production (Table 1).

PNL Volume 12 1980

RESEARCH REPORTS 15

All F1 hybrids from crossing of desynaptic mutants (lines 9 x 12) had

a high percentage of sterile pollen (from 33.0 to 76.8%). Among 125 F₂ plants

from cross 9 x 'Capital' (initial variety), 98 plants were fertile and 27 plants

were semi-sterile (X²_(3:1)=0.77^ns). The distribution among 47 F₂ plants from

cross 12 x Capital was:*33 fertile, 14 semi-sterile (X²_(3:1)=0.57^ns). We

therefore conclude that the desynaptic mutations in lines 9 and 12 were reces-

sive mutations of the same gene.

In the progenies from our desynaptic mutants a few trisomies and one

triploid were observed (Fig.l).

Fig. 1. Karyotype of triploid from line 9.



	14 RESEARCH REPORTS	PNL Volume 12 1980









	DESYNAPTIC ALLELIC PEA MUTANTS Gostimski, S. A. and T. A. Ezhova Moscow State University, USSR Two chlorophyll-mutant lines which were produced from treatment of seeds with EI (line 9) and EMS (line 12) also were found to contain meiotic mutations. These mutations seem to have arisen simultaneously with the chlorophyll mutations in the initial cells, following mutagen treatment of seeds. Study of meiosis of meiotic mutants revealed that mutant genes in both lines do not influence the process of conjugation of chromosomes in zygotene- pachytene cells, but disturb chiasma formation, though to a different extent. As a result of this disturbance, both mutant lines developed univalents in the first metaphases, laggards at anaphases, high pollen sterility, and slightly reduced seed production (Table 1).