The chlorotica mutation in line Wt11019 shows linkage with group 6 marker Pl

'Chlorophyll' mutations are quite common in Pisum. In one of our earlier experiments, mutations in this general category amounted to some 45% of all mutations observed (1). While multiplying our pea collection, we found some plants showing clear chlorophyll abnormalities in a plot of line Wt6103. The chlorotica phenotype was visible from the 3-4 leaf stage up to the flowering stage. The plants became normal in phenotype during the reproductive phase and seed set was normal. Unfortunately, the mutation does not express in greenhouse conditions. We selected the accession Wt11019 from among the mutant plants and crossed this line with our usual set of tester lines. The mutation showed monogenic recessive inheritance and evidence of linkage with group 6 marker Pl (Table 1). No other chlorotica loci are known in linkage group 6 and the locus was tentatively symbolised chi-33. There was no evidence of linkage between chi-33 and another group 6 marker, wlo (Table 1). We decided to present this preliminary data because chi-33 could be a useful morphological marker for linkage group 6.

1. Swiecicki, W.K. 1983. Hod. Rosl. Aklim. Nas. 27:221-276.

Table 1. Monohybrid (a) and dihybrid (b) segregation in the F₂ of cross
Wt11019 (chi-33, Wlo, pl) x Wt10345 (Chi-33, wlo, Pl).

¹ D = homozygous dominant + heterozygous; R = homozygous recessive. *,***,**** P < 0.05, 0.001 and 0.0001, respectively.