Genetic Variability, Heritability, and Association of Specific Leaf Area, Specific Leaf Weight, and Kernel Yield and Their Implications for Selection in Maize (Zea mays L.)
N Sabitha *
Department of Genetics and Plant Breeding, Acharya N.G. Ranga Agricultural University, S. V. Agricultural College, Tirupati 517502, Andhra Pradesh, India.
D. Mohan Reddi
Department of Genetics and Plant Breeding, Acharya N.G. Ranga Agricultural University, S. V. Agricultural College, Tirupati 517502, Andhra Pradesh, India.
D. Lokanatha Reddy
Department of Genetics and Plant Breeding, Acharya N.G. Ranga Agricultural University, S. V. Agricultural College, Tirupati 517502, Andhra Pradesh, India.
P. Sudhakar
Department of Genetics and Plant Breeding, Acharya N.G. Ranga Agricultural University, S. V. Agricultural College, Tirupati 517502, Andhra Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
The present study evaluated 45 single-cross maize hybrids developed from ten inbred lines over three seasons during 2016–17 to assess specific leaf area (SLA), specific leaf weight (SLW), and kernel yield and to examine the usefulness of SLW in the evaluated material and the gene action governing these traits. An inverse pattern between SLA and SLW was observed among both inbred lines and hybrids. Several comparatively higher-yielding inbred lines showed moderate SLA and SLW values; however, no formal correlation or regression analysis among SLA, SLW, and kernel yield was undertaken. Combining-ability analysis indicated that both additive and non-additive gene actions contributed to the inheritance of SLA, SLW, and kernel yield, with non-additive effects predominating on the basis of the reported variance components. The hybrids DFTY × PDM 1474, DFTY × Heypool, BML 7 × DFTY, BML 15 × PDM 1474, and BML 6 × PDM 1474 exhibited significant specific combining ability effects for kernel yield in the analyses presented. The inbred lines DFTY, Heypool, PDM 1452, and PDM 1474 recorded moderate SLA and SLW values together with comparatively higher kernel yield. These findings should be interpreted descriptively because they do not demonstrate a statistical association or establish a validated SLA/SLW threshold for selecting higher kernel yield. Hybrids combining favourable per se performance with significant positive SCA effects for kernel yield may be considered for heterosis breeding and subsequent hybrid development.
Keywords: Maize, specific leaf area, specific leaf weight, combining ability analysis