Reciprocal effects and combining ability in characters related to early vigor and grain yield in maize

Abstract

Early vigor is considered an essential component of crop plant development under limiting conditions. This term is used to define both a laboratory test and what is called field early vigor. Previous experiences have shown contradictory results and in the case of the reciprocal effects, sufficient information is lacking on gene action and reciprocal effects that regulate early maize vigor. The objective of this work was to evaluate the combining ability and reciprocal effects for early vigor, including grain yield, under laboratory and field conditions. Twenty hybrids resulting from a diallel cross among five inbred lines including reciprocal crosses were used. In laboratory a test simulating drought stress was performed at -1,4 MPa. Characters related to early vigor were evaluated both under laboratory and field conditions. The results showed the importance of non additive effects in the variables evaluated in the field tests, while in the laboratory tests the expression was predominantly governed by additive effects. The reciprocal effects were important for all the variables, indicating the necessity to determine the maternal inbred lines with high expression that contribute to the improvement of early vigor.