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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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Fusarium wilt race 4 [Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4)] research progress update –

 

Update FOV4 research progress update USDA-ARS and Univ. of California
PIs Drs. Mauricio Ulloa and Robert B. Hutmacher

Fusarium wilt race 4 [Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4)] research progress update – cooperative efforts by the USDA-ARS, PA, CSRL, Plant Stress and Germplasm Development Research (PSGD), Lubbock, TX, the University of California Cooperative Extension UC-ANR, and the University of CA Davis Plant Sciences Dept.

In all today, 1,155 entries have been evaluated in infested FOV4 fields and a portion (1/4) in the greenhouse using artificial FOV4 inoculation. Our primary objectives are to introduce a known FOV4 dominant gene that has shown resistance in Pima (e.g., Pima-S6) into Upland cultivars, and identify/develop within the Upland gene pool improved FOV4 tolerant germplasm. Entries have been planted in naturally-infested FOV4 fields and seeded in 5 x 1 meter plots and replicated three times. During the growing season, plant responses to inoculum pressure were assessed through evaluations of root and stem vascular staining levels, plant mortality, foliar wilt symptoms and measures of relative plant vigor. Selected cotton entries used as parents to make crosses and progeny developed from these parental entries (F1 populations) were also inoculated with FOV4 and grown under greenhouse conditions for rating and reselection. In 2013, we evaluated 511 entries in the field, including progeny from the “PS6 X TM1” and “TM1 X PS6”. In 2014, we evaluated 316 new accessions and selected 39 (12%) entries for increase and introgression of Pima resistant and Upland cultivars under FOV4 field and greenhouse evaluations. In 2015, we evaluated 207 new accessions from the USDA-ARS collection that were increased in Lubbock Texas. From 207, we selected 37 (17.5%) lines. We also received 40 U.C. Riverside lines and selected only 4 (10%).

One of the breeding methodologies applied during the identification and development of these new improved FOV4 resistant cotton germplasm is “Recurrent Selection”. So far, we made 141 selections (13% of total entries), 18 recurrent selections (2% of 2013-14 entries) and made 142 crosses (F1 populations). The 54 selections…

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University of CA and USDA-ARS Fusarium Screen Summary – 2013 trials

 

University of CA and USDA-ARS Fusarium Screen Summary – 2013 trials
Hutmacher, Wright, Ulloa et al – February 2014

Univ. California and USDA-ARS Fusarium-Race 4 Screenings (THREE SITES: Kern County and Tulare County sites plus greenhouse site at Kearney REC – 2013)

2013_Fusarium Race 4 Field Ratings SUMMARY TABLE – means and std deviations only

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Population development, selection, and evaluation for heat stress, fiber quality, lint yield, and pest resistance

 

Objectives: To improve cotton germplasm with potential heat stress tolerance, better fiber quality, lint yield and pest resistance, broadening the genetic base of cotton.

Justification and Problem Statement
Over the last 3 5 years, the cotton germplasm base used in plant breeding has narrowed. This relatively narrow genetic diversity has been suggested as a contributor to an apparent plateau in breeding progress. It may also represent an impediment to efforts to sustain high yields (May and Taylor, 1998; Meredith, 1992; Ulloa, 2006). Since the re-establishment of a cotton breeding effort within the USDA-ARS, Western Integrated Cropping Systems Research Unit, we have focused on increasing genetic diversity through acquisition of novel germplasm (from multiple sources including non-commercial land races and species of wild cottons)…

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Assessment of Fusarium in SJV Cotton: Field Evaluation Support and Variety Screening Evaluations

 

PROJECT SUMMARY
In California, Fusarium wilt of cotton has been considered a potentially serious fungal disease caused by the organism Fusarium oxysporum vas infectum (also called “FOV”). However, in the past, damage associated with Fusarium in SJV cotton has been notable only in production areas with the combination of: (a) moderate to high populations of a specific race of FOV (usually race 1 ); (b) soils witl1 a sandy or sandy loam texture; and (c) root knot nematodes present in high-enough populations to cause significant galling and root damage. Past research generally indicated that FOV damage was worst when both FOV inoculum and nematodes were present in relatively higl1 concentrations. Methods used in the past to limit damage to cotton associated with Fusarium wilt have been to avoid planting cotton in soils in which the combination of sandy or sandy loam texture is combined with the presence of root knot nematode, or grow cotton only infrequently…

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Assessment of Fusarium in the San Joaquin Valley: Field Evaluations and Variety Screening

 

Fusarium w.ilt of cotton in California has been considered a potentially serious fungal disease caused by the organism Fusarium oxysporum vas infectum (also called ”FOV”) for many decades in several areas of the San Joaquin Valley (SJV). In the past, however, damage associated with FOV in SJV cotton has been notable only in areas with the combination of: (a) moderate to high populations of one or more specific races of FOV (usually race 1 ); (b) soils with a sandy or sandy loam texture; and (c) where root lrnot nematodes were present in high-enough populations to cause some significant root damage. Past research generally indicated that FOV damage was worst when both FOV inoculum and nematodes were present in relatively high…

 

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Population development, selection, and evaluation for heat stress.

 

Summary:
Cotton is routinely grown in the hot, irrigated areas of the far Western U.S., and these extended periods of high temperature can reduce cotton ( Gossypium hirsutum L. and G. barbadense) lint yield, even with adequate irrigation conditions. Extended periods of extremely high temperatures are common in these areas during the critical stage of peak flowering. When temperatures in the San Joaquin Valley reach temperatures above normal during the critical stage of peak flowering, California growers suffer the consequences of reduced yield by these cotton varieties weaknesses to heat. The number of cotton commercial varieties for California with heat tolerance is not really known. However, it is known that Acala varieties Maxxa and Phytogen 72 yield poorly in the heat stress environment of…

 

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Western cotton (Acala, Upland, and Pima) germplasm enhancement for agronomic, fiber traits, and pest resistance

 

Summary:

Since the re-establishment of the USDA-ARS, WICS, genetic/breeding program, we have been focusing on bringing germplasm from any possible source available to us in order to increase genetic diversity. Most of the time, the genetic diversity in the cotton crop is used as an indicator to recognize potential threats to sustaining high yields. In the last couple of years, several troubling developments have recognized Fusarium oxysporum f.sp. vasirifectum (FOV) Atk. Sny & Hans as a recurring and potentially expanding threat to cotton production. The vulnerability of cotton production to this pathogen highlights the need for comprehensive research to protect the cotton industry from FOV, both from virulent populations which may be introduced and new virulent strains arising from within cotton production areas. Until recently, only race 1 and race 2 were known to occur in the United States (DeVay, 1986; Smith et al., 1981). UC scientists have recently identified race 4 ofFOV in cotton plants…

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Population development, Selection, and Evaluation for Heat Stress and Study of Seed Coat Fragments

 

The primary objective ofthis research is to identify/develop broadly adapted Acala and Upland improved cotton germplasm with potential heat stress tolerance, better fiber quality, and lint yield, broadening the genetic base of cotton. A second objective is to
investigate cotton seed coat fragment production and its genetics under different environments.

 
Summary
Cotton is routinely grown in the bot, in’igated areas of the far Westem U.S., and these extended periods of high temperature can reduce cotton (Gossypium hirsutum L. and G. barbadense) lint yield, even…

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Germplasm evaluation of cotton accessions from the U.S. Cotton Germplasm Collection, USDA-ARS (Landraces ofMexico)

 

The Gossypium hirsutum gene pool from Mexico encompasses a wide range of habitats and is one of the primary sources for improvement of most of the Acala and Upland cotton growing in the world today. Despite the existence oflarge collections of landraces of G. hirsutum, they are poorly evaluated and difficult to characterize for their value in
the collection and potential for cotton…

 

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