Selection of resistant upland cotton genotypes challenged with aggressive isolates of Meloidogyne incognita race 3
Laen...
Kuupäev
2022
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Estonian University of Life Sciences
Abstrakt
This study aimed to select populations of M. incognita race 3 for screening cotton
genotypes as part of a breeding program for the development of resistant cotton cultivars. Five
isolates of M. incognita race 3, collected in Western Paraná, Brazil, were tested for virulence and
aggressiveness against the cotton cultivars FM966 (susceptible), IAC 24 (resistant), CD 409, and
FMT 701 (moderately resistants) under greenhouse conditions, and following a factorial design
with five replicates. Thirty-one cotton genotypes were screened against the three most aggressive
isolates of M. incognita race 3 tested before and kept under greenhouse conditions following a
factorial design with five replicates. Experiments run under greenhouse conditions had single
cotton plants inoculated with 5,000 eggs/J2 of M. incognita and were assessed at 120 days after
inoculation considering the variables gall index, egg mass index, total eggs, and reproduction
factor. The same genotypes tested under greenhouse conditions were also grown in a field infested
with M. incognita race 3 in a randomized block design with 10 replicates. In the field, the
M. incognita population was monitored by the quantification of J2 forms in soil samples collected
before sowing, 60 days after sowing (DAS), and 120 DAS. A gall index score was used to
evaluate the roots of cotton genotypes at 120 DAS. The isolate from Umuarama was the most
aggressive, followed by Moreira Sales and Iporã. The genotypes CD 05-419, CD 05-945,
CD 05-1087, and CD 05-1170 showed resistance against M. incognita race 3 under greenhouse
and field conditions.
Kirjeldus
Received: July 11th, 2022 ; Accepted: August 19th, 2022 ; Published: August 25th, 2022 ; Correspondence: cfurla@hotmail.com
Märksõnad
aggressiveness, genetic resistance, Gossypium hirsutum, root-knot nematode, virulence, articles