Inheritance of Leaf Shape in Coleus

Coleus [Solenostemon scutellariodes (L.) Codd.], with various leaf forms and shapes, can be used extensively for outdoor landscaping and decoration. Crosses between commercial cultivars were conducted to understand leaf shape inheritance of Coleus. Progeny from selfing or crossing cultivars with normal leaf width were all normal width, except that progeny from selfing ‘Defiance’ resulted in a 3:1 ratio (normal: narrow). These results indicated that leaf width characteristic was controlled by a single locus, while normal width (W) is dominant to narrow width (w). Progeny from crossing between shallow-lobed cultivars all had shallow-lobed leaves, while crossing between deep-lobed cultivars resulted in a 3:1 ratio (deep-lobe: shallow-lobe). Progeny from crossing between deep-lobed and shallow-lobed leaf cultivars segregated in a 1:1 ratio (deep-lobe: shallow-lobe). These suggested that leaf margin trait was controlled by a single locus, while deep-lobe (L) is dominant to shallow-lobe (l). Cultivars with crinkled surface were crossed, and progeny fit a 3:1 ratio (crinkled: smooth). Crossing between smooth leaf cultivars produced all smooth-leaved seedlings. Progeny from crossing between crinkled and smooth cultivars all had crinkled leaves. These suggested that leaf surface trait was governed by a single locus. Crinkled surface (C) is dominant to smooth surface (c). Crossing between regular-vein cultivars, between anastomosis cultivars, and between anastomosis and regular-vein cultivars fit a 0:1, 3:1 and 1:0 ratio (anastomosis: regular-vein) respectively in progeny. This indicated that leaf vein trait was governed by a single locus, and anastomosis vein (G) is dominant to regular vein (g).