DOUBLED HAPLOIDS OF WHEAT FROM WHEAT X MAIZE CROSSES - GENOTYPIC INFLUENCE, FERTILITY AND INHERITANCE OF THE 1BL-1RS CHROMOSOME

The wheat x maize cross as a technique for haploid induction in wheat was evaluated in a replicated block design comprising 18 wheat F-1 hyb rids and five Zea mays L. parents. Haploid plants were regenerated at an average of 9.1 (4.4-14.7) plants per 100 florets processed. Genotyp ic differences for haploid production efficiency were recorded for bot h wheat and Zen mays L. Interaction between parents was significant fo r number of plants/100 florets. All 610 of the 1,703 regenerated plant lets that were analyzed by flow cytometry were haploid. At maturity, 7 0% (60-81%) of the colchicine-treated haploid plants were fertile, but the frequency of fertile and sterile plants was not consistent over t he wheat hybrids from which they were derived. Flow cytometry performe d using the first tiller which arose following colchicine treatment en abled prediction of fertility. The 1BL-1RS chromosome was found at the expected ratios in the F-2 and in the haploid progenies produced thro ugh the wheat x maize cross but deviated from the 1:1 ratio in the hap loid progenies produced by anther culture.