PEA MUTATIONS OF PRACTICAL VALUE

54 RESEARCH REPORTS

PNL Volume 12 1980

Monti, L. M., University of Naples, Portici, Italy

F. Saccardo, and P. Vitale Center of Nuclear Studies, Rome, Italy

By comparing mutagenic treatments on seed and on pollen of the canning

variety 'Sprinter', and by classifying all the mutations found in M2 for

chlorophyll and morphological mutations (Table 1), a higher frequency of

the latter types was found after pollen treatments (82.5%) than after seed

treatments (less than 36.5%).

Table 1. Frequency of mutations induced in variety Sprinter after treatment

of uollen and of seed with mutagenic agents.


Irradiation on	Mutagenic agent	Mi plant analyzed (no.)	Mutations per Mj plant (%)	Relative frequency of mutations Chlorophyll Morphological (%) (%)
Pollen	X-rays	271	14.8	17.5	82.5
Seed	X-rays	1107	16.0	80.3	19.7
	DS	372	22.3	63.8	36.2

The progenies of the morphological mutants isolated in M2 after seed

and pollen treatments were analyzed in succeeding generations, the same

selection procedure being followed from M2 on. In M3, only mutations which

could have a practical interest were considered, e.g. mutations for height,

flowering time, fertility, pod length, and seed weight and size. From M4

on, only lines with agronomic merit were selected. In M8 only two lines,

both derived from pollen-irradiated material, were superior to the control

varieties in yield (Table 2).

PNL Volume 12 1980

RESEARCH REPORTS 55

Comparative agronomic and technological trials, performed in different

Italian districts, confirmed the improved nature of the two mutant lines,

mainly for some qualities of the processed product, such as taste and color.

The certification procedure has already been started to release the two lines

as new varieties.

Comparison of the results between the two treatments seems to indicate

that pollen treatment probably induces a higher rate of the so-called point

mutations than seed treatments. This is substantiated 1) by the lower rate

of chlorophyll mutations, which are mainly attributed to chromosomal mutations,

and 2) by the higher number of high yielding lines selected from M5, on.

The higher rate of point mutations induced by pollen treatments in comparison

with seed treatments is probably due to the sieve action of the haplontic

selection at the moment of the M1 zygote formation.