Haploid regeneration aptitude of maize (Zea mays L.) lines of various origin and of their hybrids
Spitko, T × Sagi, Laszlo Pinter, J Marton, L. C Barnabas, B #
Maydica-ist sper cerealicoltur
Maydica vol:51 issue:3-4 pages:537-542
One maize line with good haploid regeneration aptitude and one recalcitrant in this respect, together with various hybrid combinations of these, were used to develop new doubled haploid (DH) lines. A line originating from an exotic Chinese stock was crossed with a recalcitrant Martonvasar line, used as a parental component in several commercial hybrids, to determine the anther response, callus induction and plant regeneration of the reciprocal hybrids and the fertility of the adult plants. The same tests were also made on previously developed DH lines of these reciprocal hybrids and on DH lines obtained after a single backcross with the recalcitrant parent. The results indicated that haploid regeneration aptitude was primarily an inherited trait in the experimental material, with a heterosis effect in the F, progeny. The hybrids exhibited no statistically significant reciprocal effect. The anther response, callus induction and plant regeneration of the DH lines developed from the hybrids and the fertility of regenerated plants were comparable to the initial combinations even when the DH line originated from a hybrid developed by backcrossing with the recalcitrant line. Data are also reported on the anther response and haploid regeneration frequency of genotypes known to have excellent tissue culturing aptitude from immature zygotic embryos. The present results may contribute to the development of an optimum gene ratio where, in addition to maintaining haploid regeneration aptitude, the DH lines also possess important agronomic traits, which are then reliably inherited.