Determination of the Best Performing Sri Lankan Maize Accessions Based on the Photosynthetic, Biomass and Yield Traits

Maize (Zea mays L.) is one of the most widely cultivated cereal crops throughout the world and is extensively grown in Sri Lanka. Information on the photosynthetic, biomass and grain yield of local maize accessions are useful for plant breeding programs. However, due to the scarcity of such information, this study aimed to investigate the potentials of maize accessions to select the best performers utilizing the rank summation and selection index criteria. As the first step, the seeds from 14 maize accessions along with two varieties viz; Pacific-999 and Bhadra (control) were established in the field. The leaf-level photosynthetic and chlorophyll fluorescence traits were analyzed, while biomass and yield traits were obtained at harvest, by employing standard techniques. Our findings revealed that traits related to growth, photosynthesis, and biomass showed greater variations among the maize accessions tested. The number of days taken to 50% flowering (44d-60d), photosynthetic rates (19.7-30.45 μmol CO2 m−2 s−1), transpiration rates (2.45-4.52 mmol H2O m−2 s−1), water use efficiency (5.69-8.13 μmol CO2 mmol H2O-1), and maximum quantum yield (0.68-0.73) among the tested accessions. Additionally, the variations in biomass (111.0-459 g/plant) and final cob yield (38-232 g/cob) were also seen among the maize accessions. According to rank summation index analysis, the maize accessions SEU2, SEU16, SEU15, SEU9 and SEU10 were superior in terms of photosynthetic rates, biomass and yield compared exhibiting with the lowest RSI values of 71, 100, 101, 103 and 117, respectively, than the cv. Bhadra. Therefore, future crop development programs can make use of these five potential maize accessions identified through this study.