what is Xenia and metaxenia? explain the related terms also with diagram
Xenia and metaxenia are phenomena dealing with the effects of pollen from different sources on certain characteristics exhibited by seeds and fruits in a variety of species. Metaxenia is still sometimes used to describe the effects on purely maternal tissues such as seed coat and pericarp.
One of the most familiar examples of xenia is the different colours that can be produced in maize ( Zea mays ) by assortment of alleles by individual pollen grains. The endosperm tissue is not produced by the mother plant, but is the product of fertilisation, and genetic factors carried by the pollen, which affect its colour. For example, a yellow-seeded variety may have its yellow colour determined by a recessive allele. If it receives pollen from a purple-seeded variety that has one copy of a dominant allele for purple colour and one copy of the recessive allele for yellow seed, the resulting cob will have some yellow and some purple seeds.