Screening corn hybrids for early-stage drought stress tolerance using SPAR phenotyping platform.

An experiment was conducted comprising of six corn hybrids that were subjected to drought and irrigated environment in separate columns in soil-plant-atmosphere-research (SPAR) cubes. The treatments and hybrids in SPAR cubes were replicated four times and a two factorial randomized complete block design (RCBD) was used to analyze the effect of drought on hybrids and their effects on traits. Significant drought × hybrid interactions were observed for most of the parameters. All the traits observed under this study were affected by drought conditions. Root volume (RV) and root shoot ratio (RSR) increased, and number of root tips (NRT), number of root forks (NRF), and number of root crossings (NRC) were drastically reduced under drought conditions. The photosynthetic rate (Phot) declined by 57.96% and electron transport rate (ETR) by 54.60% and was negatively correlated with plant height (PH) and root number (RN) during drought stress. Chlorophyll content (SPAD) showed a non-significant correlation with all the traits. As per results, there were significant differences among corn hybrids for different traits studied under the SPAR setup, which indicates that this setup successfully creates differences in treatments. A cumulative drought stress response index (CDSRI) was worked out. DKC-6581 and N61X-3110 were found to be highly drought tolerant as per our findings.