Vertical pathotypes are often called physiologic races, or pathologic races, and some plant pathologists still use these antiquated terms. Race-non-specific resistance

This clumsy term is often used as a synonym for horizontal resistance. Note that 'non-race-specific resistance' is meaningless. Race-specific resistance

This term is closely synonymous with vertical resistance. Radish

See: Raphanus sativus. Ragi

See: Eleusine coracana. Random polycross

A polycross in which the pollination is random. This is possible with allogamous species , and with an autogamous species, which responds to a male gametocide, or which has an easily controlled genetic male sterility. The advantage of a random polycross is that it produces very large numbers of crosses with very little labour. The disadvantage is that there is no control over the pollination and some parents may be more widely represented than others. Ramie

See: Boehmeria nivea. Rape seed

See: Brassica campestris. Raphanus sativus

The radish. There are four basic types, and all of them belong to this one species . The small radish is the temperate zone garden vegetable, grown commercially on quite a large scale. The large radish is popular in the Far East. Mougri-radish is grown in Southeast Asia, solely for its leaves and young seed pods, as it has no fleshy root. Fodder-radish is similar to Mougri. Suitable for amateur breeders . Rapid multiplication

With some crop species , it is possible to use a rapid multiplication technique in order to accelerate production of a new cultivar. For example, green cuttings of a potato clone can be rooted in a mist propagator and, when planted out, the cuttings will themselves produce more cuttings.

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