Selection of Gongronema latifolia Hybrids Exhibiting Heterosis for Certain Vitamins and Lycopene

摘要

Heterosis increases the productivity of a crop. Gongronema latifolia has very few and scanty records of heterosis studies and known levels of vitamin contents because it has been harvested from the wild and has a long gestation period of 14-16 months; thus, manual cross-pollination could be difficult in the species. This study was therefore undertaken to determine the levels of certain vitamins and lycopene in genotypes of Gongronema latifolia and to estimate heterosis for the traits across two years. Stem cuttings of five parent plants and their resulting hybrids were established in a field in a randomized complete block design in 2008. Young leaves from these genotypes were harvested and used to determine the levels of vitamins and lycopene and to estimate heterosis in 2009 and 2010. Better parent heterosis (BPH) ranged from −90% to 203% in both years. All vitamins and lycopene, with the exception of Vitamin C, showed positive heterosis in a minimum of five cross combinations. Vitamin E showed the highest BPH of 109% in 2009. Vitamin C had a BPH of 65% in 2010. Vitamin A, on the other hand, had a lower BPH of 52% in 2009. Two hybrids, ENS-8-MBU × AKS-33-EKPENE EDIENE and IMS-20-NJIABA × AKS-33-EKPENE EDIENE, complemented each other by exhibiting heterosis for the determined vitamins and lycopene. Selection of two hybrids with a higher level of vitamins and lycopene than in the parents should improve the availability of these nutrients, eventually at a commercial level.