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RECURRENT SELECTION PERFORMANCE FOR FOV RACE 4 RESISTANCE IN SELECTED GERMPLASM AND PROGENY

 

Abstract

Recurrent selection is being used to improve Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) resistance in Upland (Gossypium hirsutum L.) and Pima (G. barbadense L.) cotton using naturally infested fields and artificially inoculum-greenhouse sites. Our primary objective is to introduce a known FOV4 dominant gene that has shown resistance in Pima into the Upland species. In 2013, 2014 and 2015, we evaluated 1155 entries for resistance. These entries were exposed to FOV4 pressure in naturally infested fields and rated. Selected entries were then self- and cross pollinated. Parental lines and F1 populations were then inoculated with FOV4 and grown under greenhouse conditions for rating and reselection. This research will provide additional germplasm to broaden the genetic base for FOV4 resistant cotton.

Introduction

In California, Fusarium wilt of cotton is a serious fungal disease that is caused by Fusarium oxysporum f. sp. vasinfectum (FOV). Practices that have reduced the effects include not planting in sandy or sandy-loam textured soils that have a high infestation of root knot nematode and use crop rotation to help manage soil inoculum levels. This has been useful with FOV races 1 and 3, but Fusarium oxysporum f. sp. vasinfectum (FOV4) has been found to cause substantial damage in the absence of root knot nematode (Meloidogyne incognita) and persists even when crop rotation is practiced. Thus, the only long-term management of FOV4 is developing resistant cultivars. One objective of this study is to evaluate a known resistant FOV4 dominant gene from Pima (PS6) for potential introgression into Upland germplasm. The second objective is to identify and develop Upland germplasm…

 

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UC Riverside Blackeye Improvement Program-Activities at Shafter

 

Blackeyes are a well-adapted and generally profitable rotation crop for many cotton growers in the southern San Joaquin Valley. but improved blackeye varieties are needed for the California blackeye industry to remain competitive with other producing areas such as the High Plains of Texas. The major objectives of the UCR Blackeye Varietal Improvement program are to develop blackeye bean varieties and complementary management methods…

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MANAGING ROOT-KNOT NEMATODES IN COTTON: EVALUATING ALTERNATIVE AND REDUCED RISK APPROACHES

 

Cotton root-knot nematode is the most important nematode pest to cotton with losses averaging 33,360 bales/year during the period 1989 through 1998. This pest is a problem primarily in sandy and sandy-loam soils, but can be found in loamy soils.

The emphasis on reducing costs and improving profitability is a driving factor for research focused on finding alternative management approaches to fumigants and other nematicides. In addition, interest by society and regulators in seeking reduced risk approaches to pest management is driving the search for alternative nematode…

 

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