Cytomorphological and molecular characterization of interspecific F1 hybrid of Momordica dioica Roxb. Momordica subangulata subsp. renigera (G. Don) de Wilde

Abstract

Interspecific hybrid (F1) between spine gourd (Momordica dioica) and teasle gourd (Momordicasubangulata Blume subsp. Renigera (G. Don) WJJ de Wilde) produced through bagging and hand pollination showed vigorous growth habit with less fertility. Morphological parameters along with meiotic, mitotic chromosome behaviors and Randomly Amplified Polymorphic DNA (RAPD) analysis, confirmed interchanges of genetic characters in the new hybrids. The interspecific hybrid showed a vigorous foliage with intermediate flower characters than that of parental species. Self pollination and backcrossing of F1plants to either parent confirmed presence of both male and female sterility, that might be due to improper meiotic chromosome pairing. The characters like petal spot and time of anthesis (early morning) were similar to that of pollen parent while the diameter and size of leaves and flowers, pedicel length and plant growth were intermediate as compared to parents. Somatic chromosome analysis revealed 2n = 28 in M.dioica – the female parent, 2n = 56 in M. subangulata ssp. renigera - the male parent and 2n = 42 in F1hybrid of M. dioica × M. subangulata ssp. renigera. RAPD analysis of both the parents and F1 hybrid confirmed more genetic affinity (60.95%) with female parent than the male parent (32.35%). Primer specific DNA markers confirmed the introgression of male genetic elements into the newly developed amphidiploids. Incorporation of male specific DNA markers into the F1 hybrid is discussed. Preliminary evaluation indicates that the F1 plants sprouted early, which is lacking in the mother parent and this character could be exploited by restoring of fertility by chromosome doubling. Key words: Momordica, cytomorphology, F1 hybrid, karyotype, RAPD markers.