Influence of storage duration on retention of kernel tocopherols in vte4-based biofortified maize genotypes

The degradation of tocopherols during post-harvest storage poses a challenge to their efficacy in addressing vitamin E deficiency (VED), a problem faced by humans. Here, a diverse panel of vte4 gene-based inbreds along with their wild-type genotypes was analyzed to study genetic variation for retention of tocopherols during conventional storage (temperature: 25-30 degrees C and humidity: 42-82%) for six months. vte4-based inbreds possessed 2-fold higher tocopherol fractions over normal inbreds immediately after harvest [0 days after storage (DAS)]. High genetic variation for retention of tocopherol fractions viz. alpha-tocopherol (17.20-45.44%), gamma-tocopherol (30.46-44.03%), and 8-tocopherol (20.51-33.87%) was observed after six months of storage (180 DAS) among vte4-based inbreds, whereas, normal inbreds possessed comparatively low genetic variation [alpha-tocopherol (8.54-12.29%), gamma-tocopherol (23.74-27.48%) and 8-tocopherol (15.88-23.68%)]. A major fraction of alpha-tocopherol, and 8-tocopherol was lost during the last three months of storage (3rd month: 31.00% loss, 6th month: 75.22%), meanwhile, gamma-tocopherol showed comparatively slower degradation (3rd month: 31.62% loss, 6th month: 65.56% loss). HKI323-PVE (45.44%), HKI1105-PVE (24.08%), HKI161-PVE (23.17%) and HKI1128-PVE (22.73%) were the promising maize inbreds with higher retention of alpha-tocopherol at 180 DAS. These potential inbreds can be effectively used as valuable genetic resources in the biofortification programme, and the contrasting genotypes distinctly differing for retention of tocopherols can be used to map the loci for higher retention of tocopherols.

Automated summary

The retention of tocopherols during storage varied among inbreds with vte4 gene and normal inbreds. Alpha-tocopherol and 8-tocopherol showed higher rates of degradation compared to gamma-tocopherol. Several inbreds, including HKI323-PVE, HKI1105-PVE, HKI161-PVE, and HKI1128-PVE, had higher retention of alpha-tocopherol at 180 days after storage and could be valuable genetic resources for biofortification.