Brassica with resistance to an AHAS-inhibitor herbicide and blackleg disease

Abstract

Improved varieties of Brassica having an “R” rating for blackleg and resistance to AHAS-inhibitor herbicides, are provided. These varieties may be used to produce inbreds or hybrids or to produce vegetable oil and meal. Parts of these plants, including plant cells, are also provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of co-pending U.S. Ser. No. 09 / 993,751 filed Nov. 16, 2001, which claims priority under 35 USC 119(b) to PCT application Canadian Application No. 2,326,285 filed Nov. 17, 2000.FIELD OF THE INVENTION [0002] This invention is in the field of canola breeding. In particular, it relates to improved varieties of Brassica having an “R” rating for blackleg and resistance to at least one AHAS-inhibitor herbicide. BACKGROUND OF THE INVENTION [0003] Canola is an important agricultural crop in Canada, the United States, Europe and Australia. Weed competition and blackleg disease are significant limiting factors in canola crop production and quality. The challenge for plant scientists has been to develop canola varieties having superior performance with respect to these limiting factors, while at the same time having satisfactory agronomic characteristics, including yield potential, lodging resistance, oil and protei...

AI Technical Summary

Benefits of technology

[0019] This invention provides substantial value to both producers and users of canola by providing hitherto unavailable combinations of an “R” rating for blackleg and resistance to at least one AHAS-inhibitor herbicide. This trait combination improves weed control, while increasing or stabilizing yield by reducing risk of crop loss due to blackleg disease.

Problems solved by technology

Weed competition and blackleg disease are significant limiting factors in canola crop production and quality.

The challenge for plant scientists has been to develop canola varieties having superior performance with respect to these limiting factors, while at the same time having satisfactory agronomic characteristics, including yield potential, lodging resistance, oil and protein content, and glucosinolate levels that are sufficiently low for registration.

However, a drawback of currently available IMI resistant varieties is that they lack many of the desirable traits found in elite varieties of non-herbicide resistant canola.

In particular, none of the currently available IMI resistant varieties have a resistant (“R”) rating to blackleg disease.

It is particularly difficult to develop varieties having IMI resistance in combination with other desirable traits because the inheritance of the IMI resistance trait is relatively complex.

tes. Under high herbicide application rates, the AHAS3 mutant shows some injury and delay in matu

stance. The complexity of the inheritance of the IMI resistant trait results in multiple phenotypes during segregating generations, which presents a significant hurdle to plant b

Stem cankers formed early in the season may girdle the stem, causing lodging and plant death.

Less severely affected plants may remain standing but have restricted moisture and nutrient flow, causing the plant to ripen prematurely with shriveled seeds and pods.

Infection of canola pods may cause the pods to shatter prior to harvest, resulting in seed loss.

Pod infection also results in infection of the seed, which may lead to loss of seed viability.

Blackleg is therefore a serious threat to canola yield.

There are no known canola varieties that provide this advantageous combination of traits.