Morphological diversity, hybrid vigour and nutritional quality of hybrids developed from diverse quality protein maize (QPM) inbreds.

Abstract

'Hidden hunger' is an increasing concern at the global scale among both developing and developed countries. Quality protein maize (QPM) lines are nutritionally superior and with selection can be more productive than normal maize lines. However, diversification of QPM germplasm and establishing a broad genetic base is crucial to maintain a sustainable biofortified maize program. In the present study, 15 inbreds derived from diverse pedigrees, as lines (L), were crossed with three superior inbred testers (T) in L × T fashion to generate 45 hybrids. The hybrids and parents were evaluated for eight agro-morphological traits across two seasons, revealing significant genetic variation for all the traits. Classification of inbreds into different clusters revealed eight clusters, indicating substantial genetic divergence among inbreds. Additionally, the QPM inbreds and their hybrids were characterized for lysine and tryptophan content. The average lysine among inbreds and hybrids was 3.37% and 3.39%, respectively, whereas the average tryptophan content was 0.84% and 0.89%, respectively. For grain yield, significant heterosis was recorded at the mid-parent and better parent level. Hybrid G12 × G16 (111.91%) at the better parent and hybrid G2 × G17 (135.12%) at the mid parent level were found to have the highest heterosis. These findings established that, leveraging nutritional superiority, a heterotic breeding program can be established for QPM. Wide genetic variation among inbreds can be utilized to develop diverse populations, as observed in the African maize biofortification program. Therefore, the present study reveals potential for establishing a sustainable, broad-based QPM breeding. © 2026 Society of Chemical Industry.