AbstractI. Selections were made of single plants from a large, apparently constant, population of apomictic Rubus nitidioides Watson. The characters selected were high and low frequency of prickles and early flowering.
2. The progenies of one high prickle selection and one low selection were very different in the intensity of their prickles. Selection for early flowering produced a very early flowering progeny.
3. Associated with these selections were other characteristics, such as delay in first flowering (except for the early flowering strain), a general decrease in heights and plant vigour, changes in leaf colour and shape, and partial sterility. These associated differences were also carried over to the third selection. An unselected progeny remained highly vigorous, prolific, and with healthy green leaves true to type.
4. In the high prickle selection, the associated taxonomic differences of the leaves showed resemblances to those of other species taxonomically related to R. nitidioides.
5. The bearing of these selections on the evolution and speciation of apomictic Rubi is discussed. It is possible that the diplosporous mechanism is associated with the polytopical origins of apomictic microspecies.