COMPARATIVE PERFORMANCE OF F2- AND BC1F1- DERIVED DOUBLED HAPLOIDS IN MAIZE (ZEA MAYS L.)

Abstract

Conventional method of developing homozygous lines for use as parents of hybrid cultivars in crops including maize is time and resource demanding process. Doubled haploid (DH) induction is the quickest method of developing homozygous lines. Breeders most frequently induce DHs from heterozygous generation such as F1’s of breeding crosses, referred to as breeding populations (BPs). Simulation experiments have indicated that induction of DHs from F2 BPs not only help break undesirable linkages but also offer selection prior to induction. However, considering that F2 and BC1F1 (backcrossing F1 with superior parent) require same time for development, we hypothesized that per se performance of BC1F1-DH would be greater than those of F2 DHs, especially when one parent of the breeding crosses is better than the other. This hypothesis is based on the rationale that frequency of favourable alleles would be increased in BC1F1. To test this hypothesis, we developed doubled haploids (DH) from F2 and BC1F1 populations derived from four crosses using in vivo maternal induction at CIMMYT haploid induction facility located in Agricultural research station (ARS) Kunigal, Karnataka, India. These DHs were evaluated in two-replicated alpha lattice design for grain yield. The results indicated that the estimates of mean grain yield, frequency of transgressive segregation (TS) of DHs derived from BC1F1 BPs were greater than those derived from of F2 BPs in all the four breeding crosses. Implications of these results are discussed in relation to adoption of appropriate strategies for rapid genetic gain in maize.