Genetic control of fruit length, external colour and number of fruits per vine in bitter gourd studied using Charantia × Muricata crosses

The present study was undertaken to ascertain the genetic control of external fruit colour, fruit length, and the number of fruits per vine in bitter gourd using reciprocal crosses of Momordica charantia var. muricata and M. charantia var. charantia and to identify suitable lines of M. charantia var. muricata to be used in bitter gourd improvement programmes. Muricata accession collected from Girandurukotte (GK), Sri Lanka, was selected as a suitable accession for crop improvement based on higher gynoecy and consistency of characteristics. Crossing success between Charantia and Muricata varieties was 100 % indicating cross-compatibility between the two types. External fruit colour, fruit length and the number of fruits per vine of bitter gourd were found to be quantitative traits, potentially controlled by many genes, each with a small effect. The number of fruits per vine was found to show cytoplasmic inheritance, as the F1 generation recorded fruit numbers per vine similar to those of Charantia varieties, when Charantia varieties were used as the female parent of the reciprocal crosses made between Charantia and Muricata varieties. However, the suspected cytoplasmic effect was not useful, as it influenced to reduce the number of fruits per vine. In addition, the number of fruits per vine showed several transgressive segregants in both extremes of the F2 populations. In bitter gourd improvement programmes, GK Muricata accession may be used to improve cultivated Charantia varieties with respect to fruit characteristics such as external fruit colour, fruit length and the number of fruits per vine through a breeding program with the directional selection made towards obtaining the desired characters.