Sterile seeds, or seeds that fail to develop into viable plants, may result from crosses between distantly related plants due to genetic incompatibility. When plants from different species or even different genera are crossed, their genomes may not be compatible, leading to abnormal development of the embryo and endosperm, which are essential for seed development.
One way to overcome this problem is to use techniques such as embryo rescue or ovule culture. In embryo rescue, the embryos are isolated from the developing seeds and placed in nutrient media where they can develop into viable plants in a controlled environment. In ovule culture, the ovules are isolated from the parent plant and cultured in nutrient media to allow for their development into viable seeds.
Another approach is to use techniques such as somatic hybridization or genetic engineering to introduce desirable traits from one plant species into another. Somatic hybridization involves fusing protoplasts from different plant species to create hybrid plants with desirable traits, while genetic engineering involves inserting specific genes into the genome of a plant to introduce desirable traits.
In summary, sterile seeds may result from crosses between distantly related plants due to genetic incompatibility, but this can be overcome using techniques such as embryo rescue, ovule culture, somatic hybridization, or genetic engineering.