PNL Volume 17 1985 RESEARCH REPORTS

PIGMENT CHANGES DURING THE ONTOGENY OF PLANTS

Schmitz, R.

Institute of Genetics, University of Bonn

Federal Republic of Germany

Numerous chlorophyll mutants of pea and other species have been

described. When the chlorophyll concentration of these mutants is

measured, usually the determination is made at a single stage of

development. Still, it is known that there are changes in pigment con-

centration during the ontogeny of plants. Therefore, three chlorophyll

mutants were investigated in comparison with the initial line (IL)

'Dippes Gelbe Viktoria' at three stages of ontogeny:

I. Plant with ten leaves

II. Beginning of flowering

III. End of flowering

The pigments were determined in plants grown under field conditions.

Variation in chlorophyll concentration of leaves from the four genotypes

is shown in Fig. 1. Leaves from the upper nodes had a higher pigment

concentration than leaves from the lower nodes but the genotypes showed

different rates of increase. The difference in concentration between

the mutants and the IL was greatest at node 18, while the leaves at node

5 showed only a slight deviation.

Fig. 2 shows how the pigment concentration changed in the leaves

from node 5 and node 8. The chlorophyll content decreased, especially

in the IL. Only mutant 29 exhibited an increase in pigments.

The decrease of pigments in the lower leaves was the result of

senescence. However, the decline of chlorophyll in different stages was

not the same for all genotypes, the mutants showing less reduction than

the IL.

Whenever attempts are made to correlate pigment concentration with

productivity, due consideration should be given to the variation of pig-

ments during the ontogeny of the plants.

Fig. 1.

Chlorophyll concentration of leaves

from nodes 5, 8, 12, 15, and 18 at

the end of flowering.

Fig. 2.

Chlorophyll concentration of leaves

from node 5 and node 8 in three stages

of ontogeny (I, II, and III.) IL -

initial line 'Dippes Gelbe Viktoria';

29-chlorotica mutant; 130A and 1206A-

mutants without chlorophyll b.