A SIMPLE TECHNIQUE FOR THE IDENTIFICATION OF EMBRYO-CARRYING SEEDS FROM WHEAT X MAIZE CROSSES PRIOR TO DISSECTION

Embryo rescue is an important step in the wheat x maize system of indu ced haploidy in wheat. On average, only one-third of the seeds carry e mbryos, but they all have to be dissected because no morphological dis tinction is available to distinguish between seeds with and without em bryos. We here report a simple technique in which immature seeds from wheat x maize crosses are placed on a transparent surface and illumina ted from above. The free-floating embryo, settled at the bottom of the seed, can be seen from below or in an image reflected on a plane mirr or. Using this technique 97.8% of the embryo-containing seeds could be detected prior to dissection. The technique will be useful in reducin g the time and labour involved in embryo culture, thereby scaling up h aploid production.