Accelerated development of maize inbred lines suitable for high density through doubled haploid technology

Aim: Doubled haploid technology was utilized to accelerate the development of maize lines with traits suitable for high planting density, enabling the identification of potential parental lines for hybrid development under these conditions. Methodology: Two F1 populations (PML-119 x PML-185 and PML-95 x PML-172) were used to generate doubled haploid lines, confirmed using polymorphic markers phi115 and umc1887. These lines were phenotypically evaluated under high density (60 cm x 15 cm) and normal density (60 cm x 20 cm) conditions. Results: Using doubled haploid technology, 67 lines were developed from two source populations with traits such as narrow leaf angle, moderate plant height, and sparse tassel for high planting density stress tolerance. Molecular marker screening confirmed the homozygosity of these lines. Agronomic evaluation under narrow plant-to-plant spacing (15 cm) identified eight potential donor lines amenable to high planting density stress, ready for use as parents in breeding high-density tolerant hybrids. Interpretation: Potential donor doubled haploid lines viz. DH2-4, DH2-8, DH2-9, DH2-11, DH2-14, DH2-15 derived from Population-3 X CIM2GTAIL P2 and DH2-4, DH2-23 derived from Population-9 X CIM2GTAIL P2 were identified for utilization as putative parents of hybrids suitable for planting under high planting density conditions. Key words: Doubled haploid, High plant density, Maize, Plant architecture, Yield