Cytoplasmic Male Sterility And Their Role In Sugar Beet Breeding

1- Male Sterile: Some plants which have no pollen grain are male sterile or White sterile. In contrary there are some fertile plant with many pollens, and in between there are two groups yellow Sterile md  Half Fertile".
2-..visual Differences:
a- white sterile- Stigma are white and has no pollen grain. b --Yellow Sterile- stigma. are orange color and have a few pollen grains.
c-Half Fertile are in some cases similar to Y.S. and in the other cases to the fertile flowers so, it is very difficult to recognize by eyes •
d-Fertile-Stigma are Swollen, yellowish and with many pollen grains.
3-Microscopical Differences: By using 1fuschine acid solution it can be recognized very easily.
a-W.S. have no pollen grain.
b-Y.S. have some small and white pollen grains.
c-H.F. has different ratio of safe, red pollen grain•
d-Fertile plants have more than 80% completely red pollen grain.
4-Genetical Formula-White sterile result from two recessive genes x and z with cytoplasmic factor s, so the formula is "S:xx The dominant allele of the gene x restores Complete, male, fertile and the dominant allele of a second gene Z which is independent of and hypostatic to X restores partial fertility.
5- Production: At first it is necessary to find corresponding Type N_xxzz and after that it should be used this 0 'Type as a pollinator for pollination of male sterile and produce the seed.
6- Plant Breeding Uses: Cross with different diploid and tetraploid male fertile plants for general combining ability and use for, polyploid, and Triploid Multigerm and Monogerm varieties.