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Acquisition, identification and analysis of an interspecific Capsicum hybrid (C. annuum × C. chinense)

Shi, Y. H., Hu, N. B.
Journal of horticultural science & biotechnology 2015 v.90 no.1 pp. 31-38
Capsicum annuum, abnormal behavior, anthocyanins, biotechnology, breeding, capsaicin, chromosomes, color, cultivars, flowers, genes, horticulture, hot peppers, hybrids, inheritance (genetics), internal transcribed spacers, isozymes, leaves, mutation, parents, pepper, peroxidase, plantlets, pollen, random amplified polymorphic DNA technique, ribosomal DNA, sequence analysis, transcription (genetics)
Using an embryo rescue technique, we obtained an F1 plantlet whose female parent was a purple chilli pepper (Capsicum annuum 7033) and whose male parent was a green chilli pepper (C. chinense 7020). We verified the origin of this interspecific hybrid using a peroxidase isozyme assay and random amplified polymorphic DNA (RAPD) markers. Most of the morphological features of the F1 plant, particularly the purple colour of its foliage, flowers and immature fruit, were intermediate between those of its parents. Cytological analysis indicated that the meiotic chromosomes of the pollen mother cells of the F1 plant exhibited abnormal behaviour, resulting in a marked reduction in the proportion of fertile pollen compared to both its parents. Sequence analysis of the internal transcribed spacer of nuclear ribosomal DNA demonstrated that, compared to the parental sequences, the F1 hybrid had 186 polymorphic sites, 139 of which (74.7%) were inherited from the male parent, and 23 (12.4%) were inherited from the female parent, and 24 (12.9%) were transversions or base pair mutations. Therefore, our morphological and cytological observations, as well as isozyme and molecular marker analyses confirmed that the F1 plant was a genuine interspecific hybrid that had inherited more genetic information from its male parent than from its female parent. This work will help locate purple colour-related genes and the breeding of pepper cultivars containing higher concentrations of anthocyanin and capsaicin.