Heterosis in crosses between wheat genotypes with different spike architecture

In order to estimate hybrid vigor, wheat genotypes differing in spike architecture (normal, tetrastichon and branched) were crossed and the F1 and F2 generations analyzed for the number of fertile spikelets/spike, number of grains/spike and grain weight/spike. The parents used for crossing were Sava (normal spike), Forlani (normal spike), ZG T 171/1 (tetrastichon spike) and ZG 172 (branched spike). The F1 and F2 progenies, except those from the cross Sava x Forlani, had a lower number of fertile spikelets/spike compared with the better parent. In the crosses between genotypes with normal and branched spikes, the F1 and F2 progenies formed significantly fewer grains/spike. On the other hand, the F1 of the crosses between genotypes with normal and tetrastichon spike showed a significant level of heterosis with respect to the number of grains/spike, particularly the cross Forlani x ZG T 171/1. In regard to grain weight/spike, significant heterosis was detected in all crosses except Sava x ZG 172.The crosses between genotypes with normal and tetrastichon spikes that exhibited significant heterosis for two main yield components were most promising in the context of hybrid wheat development. Such crosses deserve further attention and investigation.