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

Abstract

AbstractThe 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.