Development of improved horticultural genotypes characterized by novel over-flowering inflorescence trait in periwinkle Catharanthus roseus

Abstract

Floricultural genotypes with new plant architecture were developed in the seasonal/perennial garden plant Catharanthus roseus. The new genotypes were developed by crossing the double mutant line lli egd of C. roseus with two horticultural lines of C. roseus and a line of Catharanthus trichophyllus. As compared to the normal LLI inflorescence architecture in which racemose inflorescence had pairs of flowers subtended by one of the two leaves per node, the lli inflorescence of the new lines was excessively branched and each branch had two flowers per node which were bereft of subtending leaves. The new lines are novel in displaying several fold increased number of flowers on inflorescence unhindered by leaves. In the new floricultural lines the over-flowering lli trait was combined with variation in plant height, petal and eye colors and tolerance to the common fungal diseases.