A Diallel Analysis of Ear Moisture Loss Rate in Maize

Abstract

Maize (Zea mays L.) growers need hybrids with fast ear moisture loss rate (EMLR) to reduce grain drying cost. A 10‐parent diallel experiment with reciprocals (Griffing's Method 3) was conducted for 2 yr to study the genetic nature of EMLR in maize. Field ear moisture was measured with an electronic probe device at 30 and 51 d after midsilk. Analysis of covariance (ANCOVA) was used to increase precision of treatment comparisons and parameter estimation since F1 crosses differed in midsilk dates and in growing degree days (GDD) between the first (Moisture1) and the second probe moisture readings (Moisture2). Adjusted plot means were used to compute combining abilities. General combining ability fixed variance component (GCA, Vg) and reciprocal component were significant, whereas specific combining ability fixed variance component (SCA, Vg) was not significant for EMLR. The 2Vg/(2Vg + Vg) ratio was 0.81, indicating that GCA effects were more important than SCA effects for EMLR. Significant, positive GCA effects for EMLR were detected in L108, L605, and L654 inbred lines and negative GCA effects in Mo17 inbred line. Non‐maternal component was significant for EMLR. Moisture1 and Moisture2 also were genetically controlled. A relatively low Moisture1, high EMLR, and positive GCA and reciprocal effects for EMLR were important in lowering Moisture2. Specific interaction between nuclear genetic component(s) and non‐nuclear genetic factors can be exploited for enhancing EMLR. Inbred lines L668, B73, and H111 had relatively low Moisture2 due to either relatively low Moisture1 or high EMLR or both. In general, Louisiana (L) lines had higher Moisture1, Moisture2, and EMLR than B73, H111, and Mo17.