Analysis of genetic variability and genotype x year interactions on kernel zinc concentration in selected Indian and exotic maize (Zea mays) genotypes

Analysis of genetic variability for kernel zinc (Zn) concentration was undertaken on 81 maize (Zea mays L.) genotypes, including 13 inbreds from CIMMYT-HarvestPlus, in this study. Kernel Zn concentration varied significantly with a range of 3.81 to 35.83 mg/kg across three years of evaluation (2006-2008). Among the genotypes evaluated during 2006, IML 289 showed highest kernel Zn concentration (35.83 mg/kg), followed by HP 12 (31.69 mg/kg), HP 35-6 (29.02 mg/kg), HP 1 (27.24 mg/kg) and IML 119 (25.77 mg/kg). During kharif 2007, nine genotypes recorded kernel Zn more than 25 mg/kg. Among the landrace accessions, IML 312 (30.30 mg/kg), IML 185 (28.56 mg/kg), IML 288 (26.34 mg/kg), IML 119 (25.88 mg/kg) and IML 390 (25.75 mg/kg) were found promising, while the inbreds BAJIM 06-5 (28.72 mg/kg), CM 145 (25.89 mg/kg), CM 127 (25.45 mg/kg) and BAJIM 06-12 (25.44 mg/kg) recorded kernel Zn concentration. Among the inbreds evaluated during 2008, BAJIM 06-1 (24.74 mg/kg) was identified as the best genotype, followed by V 336 (23.36 mg/kg), CM 145 (22.18 mg/kg), CM 140 (21.09 mg/kg), V 340 (20.56 mg/kg), V 348 (20.17 mg/kg) and BAJIM06- 6 (20.02 mg/kg). The study revealed significant genotype x year interaction for kernel Zn concentration. Stability analysis revealed that variances due to genotype, year + genotype x year, year (linear) and pooled deviation were significant. Taking into consideration of regression coefficient and deviation from linearity, V 336, VQL 1, V 334 and CM 139 could be identified as stable genotypes for kernel Zn concentration across the years.