Many breeding populations of sweetcorn have been developed for resistance to corn earworm, Heliothis zea, using Zapalote Chico (ZC) lines as a main resistance genetic resource. We are evaluating ZC as a source of drought and heat tolerance and to determine if ZC confers such tolerance to Hawaiian Super Sweet (HSS) developed at University of Hawaii. We are comparing the genetic potency of single-eared ZC landrace that is segregating for purple stem and tassel, and green stem and tassel in a hybrid with the the all-green, double-eared HSS. Forward and reciprocal hybrids were developed between HSS for a total of four hybrid sub-groups incorporating the two color sub-groups of ZC and HSS as the parents. The hybrids were developed at the University of the Virgin Islands, agInnovation Research Station. The F1 and the parents were evaluated under three levels of severity of deficit irrigation and exposed to the same level of summer heat. Fresh yield, sweetness and time to harvest were compared among the F1s. Preliminary results show that based on the three metrics we used, the HSS/ZCpurple had a higher tolerance to water deficit than the HSS/ZCwhite, while no significant difference were observed among the reciprocal F1s. The double-eared HSS/_derived hybrids may have the potential to improve sweetcorn production for the Virgin Islands small-scale producers Key words: Abiotic stress, genetics, hybrid, sweetcorn, Zapalote Chico
