Genetic analysis of several flowering and branching mutants in Pisum sativum L.

Three flowering mutants and 17 branching mutants were studied. The three induced early flowering mutants showed monogenic inheritance. Mutants L167 and M2/176 are the result of recessive mutations at the established loci Lf and Sn, and the mutant alleles appear equivalent to If and sn, respectively. Mutant M2/137 is the result of a single gene partially recessive mutation at a new flowering locus, for which symbol ppd (photoperiod response) is proposed. Ppd is located on chromosome 1 about 32 cM from A. Fifteen of the 17 branching mutants studied were shown to be single gene recessive mutants while the node of inheritance for two mutants, K319 and K586, was not clear. K319 is possibly a single gene dominant mutant, whereas K586 is possibly a single gene, recessive mutant with weak expression which needs the right conditions to produce laterals. Based on the results of allelism tests, the 17 branching mutants were grouped into 7 series. Mutants WL5147, WL5237, WL5918, Wt15236 and Wt15240 are all allelic and the result of mutation of gene Rms since WL5237 is the type line for rms. Ten further mutants represent mutation at four new ramosus loci designated rms-2 (mutants WL5951 and K524), rms-3 (mutants WL6042, K487, and K564), rms-4 (mutants K164 and Wt15242) and rms-5 (mutants Wt10852, Wt15241 and Wt15244). The remaining two mutants, K319 and K586 do not appear to be allelic with each other or rms-1, 2, 3, 4 or 5 (rms=rms-1).