Plant Variety Protection Office (PVPO) E-News

This newsletter provides news about the PVPO team, helpful Plant Variety Protection (PVP) 

tips, and other valuable information that we are certain you will find useful. 

In order to obtain PVP, a variety must be new, distinct, 

uniform, and stable and have a name 

(denomination). We discussed the concept of New 

(novelty) as it relates to PVP in the last newsletter. In 

this issue, we discuss the concepts of Distinct, Uniform, 

and Stable (DUS). 

Distinct

A distinct variety is clearly different from all varieties of common knowledge. Common 

knowledge varieties are those that are known to exist at the time the application is filed. A 

variety may be considered to be clearly distinguishable if the difference in characteristics is 

consistent (i.e. the same over independent occasions or locations) and clear. For example, a 

variety that produces violet flowers would be clearly distinguishable from a similar variety that 

produces pink flowers. Other common distinguishing traits include plant height, seed color, 

seed shape, and fruit size, to name a few. Differences in yield cannot be used as a basis for 

distinction, because yield is influenced by the environment (e.g., by temperature, sunshine, 

rainfall, pests and diseases) and other factors and may not be consistent. 

Example of 3 Distinct Tomato Varieties 

(Each row is a distinct variety based on a combination of fruit shape and size)

Row 1 = Variety ‘Indigo Pear Drops’ (PVP Certificate # 201500116)

Row 2 = Variety ‘Indigo Cherry Drops’ (PVP Certificate # 201500117)

Row 3 = Variety ‘Indigo Rose’ (PVP Certificate # 201100302)

Photo provided courtesy of Oregon State University
Uniform

A variety is uniform in the sense that all plants of the variety look alike and any variations are 

describable, predictable, and commercially acceptable. Commercially acceptable variations 

are those considered as satisfactory when the variety is marketed to the public. 

Examples of Uniform and Not Uniform Varieties

 Uniform Variety Variety is not Uniform

Stable

A variety is stable when it produces true to type in the sense that important characteristics 

remain unchanged in repeated generations. For example, if a variety produces red flowers, it 

is considered stable if it continues to produce red flower in its second or third generation, but 

is unstable if it produced a mix of red, white, and pink flowers in future generations.

Example of an Unstable Variety

Original material Generation 1 Generation 2 Generation N 

 

The distinct, uniform, and stable characteristics of a variety are the cornerstones of the PVP 

system. We will discuss how DUS trials are conducted in a future newsletter issue.

We welcome your suggestions on topics for future newsletters as well as ideas on how we 

can improve our service. Please feel free to contact the PVPO if you have any questions, 

comments, or suggestions.

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For more information, please contact:
Plant Variety Protection Office

Science & Technology Program

Agricultural Marketing Service

United States Department of Agriculture

Office: (202) 720-1128

PVPOmail@ams.usda.gov