Inheritance of Multifoliolate Leaves, Glabrous Leaves, and Petiolulate Leaflet Attachment in Crimson Clover, Trifolium incarnatum L.1

Abstract

Inheritance of multifoliolate leaves, glabrous leaves, and petiolulate leaflet attachment was studied in the F1, F2, and F3 generations of crimson clover, Trifolium incarnatum L. Normal crimson clover has trifoliolate, pubescent leaves and sessile leaflet attachment. Inbred, recessive white‐flowered lines were used as the female parent in studying these mutants: glabrous leaves (g); petiolulate leaflets (p); and multifoliolate leaflets (mI). Segregation ratios for multifoliolate leaves, glabrous leaves, and petiolulate leaflets fit expected segregation ratios of 3:1. Each of the characteristics studied appears to be controlled by a single recessive gene pair. Intermediate forms were not observed, an indication that only a single gene pair was involved in each mutant. One mutant was a double recessive with glabrous leaves and petiolulate leaflet attachment. Heterozygous F2 and F3 populations from the double recessive segregated on the basis of a 9:3:3:1 ratios as expected; thus showing independent inheritance for these two characters.The following genetic symbols are proposed: G for pubescence, and g for glabrous; P for sessile leaflet attachment and p for petiolulate leaflet attachment; and Ml for trifoliolate leaves and ml for multifoliolate leaves.These characteristics should help determine effective hybridization in the crossing and breeding program. As more marker genes are accumulated, specific chromosomes and chromosomal regions can be identified. Some of these mutants will be of interest morphologically and of possible value as physiological indexes, e.g., multifoliolate leaves.