Kentucky Bluegrass Is a Widespread Turfgrass Used for Lawns Throughout

Kentucky Bluegrass is a widespread turfgrass used for lawns throughout the United States. In some regions, strains have developed desirable disease-resistant properties. However, Kentucky Bluegrass typically develops by apomixis. Plant breeders say this creates both a challenge and an opportunity for engineering novel strains. Why?

A) In apomixis, new plants develop from underground horizontal stems. This allows for fast propagation of new strains, but all progeny are identical to the parent.
B) Plants that develop by apomixis are naturally tolerant of herbicides. As a result, herbicide tolerance genes cannot be used as selectable markers for a transgene, but herbicides can be used to keep the resulting culture pure.
C) Since the progeny of apomixis are triploid, hybrids have an imbalance of parental genes. However, this may be desirable if a higher proportion of one allele is beneficial.
D) If a seed develops by apomixis, it will be identical to its parent. Hybridization with another strain requires special techniques. However, once a hybrid strain is developed, apomixis ensures its reliable propagation.