Evaluation of commercial Upland (Gossypium hirsutum) and Pima (G. barbadense) cotton cultivars, advanced breeding lines and glandless cotton for resistance to Alternaria leaf spot (Alternaria alternata) under field conditions

Idowu

Wedegaertner

2020

Self Cite

The New Mexico Agricultural Experiment Station announces the release of a glandless ‘NuMex COT 17 GLS’ cotton (Gossypium hirsutum L.) (Reg. no. CV‐141, PI 691837), which carries the incomplete dominant glandless allele Gl2e. NuMex COT 17 GLS was derived from an advanced backcross progeny of a cross between the Gl2e allele donor ‘Bahtim 110’ (G. barbadense L.) and glanded upland cotton ‘CRI 12’, followed by five backcrosses with glanded upland ‘CRI 35’ as the recurrent parent. It is resistant to Fusarium wilt (FW) race 4, with a level of resistance similar to the resistant checks ‘PHY 802RF’ and ‘PHY 811RF’, when evaluated in two naturally infected fields in California, and it is more resistant than ‘Acala 1517‐08’ when evaluated in the greenhouse in New Mexico. This new cultivar was tested in seven replicated field trials in New Mexico in 2013–2017 and in 11 tests across nine states in 2014. Compared with glandless ‘Acala GLS’, ‘Acala 1517‐18 GLS’, and ‘NuMex COT 15 GLS’, NuMex COT 17 GLS yielded 26, 16, and 13% more lint, respectively, and produced 93% of glanded Acala 1517‐08 yield. It had significantly higher lint percentage than all the check cultivars. It is classified as a medium staple with fiber quality inferior to long‐staple Acala cotton cultivars. NuMex COT 17 GLS is especially adapted to the Mississippi Delta and was the top yielder in the region. It is resistant to four races of bacterial blight and less susceptible to Alternaria leaf spot than Acala 1517‐08. The release of NuMex COT 17 GLS represents one of the first successful introgressions from G. barbadense germplasm with FW race 4 resistance.

Section: Methodsmentioning

confidence: 99%

Registration of glandless ‘NuMex COT 17 GLS’ upland cotton cultivar with Fusarium wilt race 4 resistance

Idowu

Wedegaertner

2020

Self Cite

“…In September 2016, 10 plants in each plot of AYT, OVT, and RHQ tests also were screened for resistance to Alternaria leaf spot (ALS) [caused by Alternaria alternata (Nees:Fr.) Keissler] under natural field conditions in Las Cruces, NM, based on a rating scale of 0 to 5 (Zhu et al., ). The average severity rating was converted to disease severity index by dividing it with the highest rating of 5, and disease severity indices were used for ANOVA and LSD calculations.…”

Section: Methodsmentioning

confidence: 99%

Registration of upland cotton cultivar ‘Acala 1517‐20’ resistant to Fusarium wilt race 4

2020

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The New Mexico Agricultural Experiment Station announces the release of an upland cotton (Gossypium hirsutum L.) cultivar ‘Acala 1517‐20’ (Reg. no. CV‐142, PI 691836). Acala 1517‐20 was derived from a single plant selection in a biparental cross between an unreleased upland line NM 010368 and a Chinese cultivar ‘Jimian 958’ that is resistant to Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum, FOV) race 7. Acala 1517‐20 is moderately resistant to FOV race 4 (FOV4), similar to ‘Pima DP 358 RF’, based on vascular root staining and growth vigor in the field in California and foliar disease severity ratings in the greenhouse in New Mexico. This new cultivar was tested in nine replicated field trials in New Mexico in 2008–2017 and in 20 tests in 14 locations across 12 states in 2016–2017. Acala 1517‐20 yielded similarly to the high‐yielding Acala cotton cultivars, including ‘Acala 1517‐99W’, ‘Acala 1517‐16 B2RF’, and ‘Acala 1517‐08’, and the Acala‐type transgenic commercial cultivars, including ‘PHY 725 RF’, ‘PHY 755 WRF’, ‘PHY 764 WRF’, and ‘FM 2322 GL’, but yielded lower than ‘FM 1830 GLT’. Compared with Acala 1517‐08, Acala 1517‐20 had higher lint percentage, lower boll and seed weight, and lower short fiber content. Acala 1517‐20 was susceptible to four races of bacterial blight and Alternaria leaf spot. It is recommended for regions where Acala cotton is grown in the presence of FOV4. It will also provide a new source of resistance to FOV4.

“…In September 2016, 10 plants in each plot of AYT, OVT, and RHQ tests were also screened for resistance to disease infections from Alternaria leaf spot [ALS, caused by Alternaria alternata (Nees:Fr.) Keissler] under the natural field conditions in Las Cruces, using a rating scale of 0–5 (Zhu et al., 2018). The average severity rating was converted to disease severity index by dividing it with the highest rating of 5, and disease severity index was used for ANOVA and a LSD calculation for each test.…”

Section: Methodsmentioning

confidence: 99%

“…Based on the results of Zhu et al. (2018) from five replicated field tests conducted in Las Cruces in 2016–2017, Acala 1517‐21 was susceptible to Alternaria leaf spot under natural infection conditions. Acala 1517‐21 was also evaluated for FOV4 resistance using an artificial inoculation method in the greenhouse in 2018.…”

Section: Characteristicsmentioning

confidence: 99%

Registration of ‘Acala 1517‐21’ Cotton Cultivar

2020

Self Cite

The New Mexico Agricultural Experiment Station announces the release of upland cotton (Gossypium hirsutum L.) cultivar 'Acala 1517-21' (Reg. no. CV-144, PI 693757). Acala 1517-21 was derived from a single plant selection in F 3 from a bi-parental cross between LA05307029 and AU-5491. This new cultivar was tested in eight replicated field trials in New Mexico in 2012-2017 and 21 tests across 12 states of the Cotton Belt in 2016-2017. In New Mexico, Acala 1517-21 yielded similarly to medium-staple cultivars or transgenic commercial Acala cultivars including 'PHY 725 RF', 'PHY 755 WRF', 'PHY 764 WRF', 'FM 2322GL', and 'FM 1830GLT'. Compared with 'Acala 1517-08', Acala 1517-21 averaged 12.9% higher lint yield and 11.5% higher lint percentage, with a similar boll weight, fiber length, length uniformity, elongation, micronaire, and short fiber content. However, Acala 1517-21 had similar or slightly lower fiber strength with significantly lower strength and elongation in one test. Compared with commercial transgenic and nontransgenic cultivars across the Cotton Belt, Acala 1517-21 had consistently longer and stronger fibers or lower micronaire readings. Acala 1517-21 represents a high-yielding upland cotton cultivar with high lint percentage and a long staple. 1 INTRODUCTION Upland cotton (Gossypium hirsutum L.) produces more than 95% of the raw cotton with a short (<25 mm) to medium (25-30 mm) staple length globally, while the remaining cotton is predominantly produced by G. barbadense L. (known as pima, Egyptian, or Sea-Island cotton) with long-staple (LS, 30-35 mm) or extra-long-staple (>35 mm) fibers. Acala cotton is a special type of upland cotton and known for its premium fiber quality, and it produces long-staple or near-long-staple fibers developed and grown in New Mexico and California. Among 37 Acala 1517