This work aims to identify 'A' and 'B' onion lines in Brazilian germplasm, associating marker-assisted selection (MAS) of cytoplasm type and the Ms locus with pollen viability analysis. MAS and pollen viability tests presented a complete agreement for the lines Alfa SF, BRS 367, BRS 367, Cascuda T7, Cascuda T5, EHCEB 20102017 and EHCEB 20142027. MAS was not validated by the pollen viability tests in some plants of the lines Alfa SF, EHCEB 20142028, EHCEB 20141028, EHCEB 20141027 e EHCEB 20141017. Plants with fertile pollen within a specific 'A' line were eliminated before anthesis. The methods used to evaluate pollen viability did not present agreement in the sterile and fertile classification in five onion accessions. Six pairs of 'A' and 'B' lines identified in the present study [Alfa SF (Tmsms) x Alfa SF (Nmsms), BRS 367 (Tmsms) x BRS 367 (Nmsms), Cascuda T7 (Nmsms) x Cascuda T5 (Smsms), EHCEB 20142027 (Nmsms) x 20141027 (Tmsms), EHCEB 20102017 (Nmsms) x EHCEB 20141017 (Tmsms), and EHCEB 20142028 (Nmsms) x EHCEB 20141028 (Smsms)] have potential for onion hybrid development.
The objective of this study was the identification of the cytoplasmic types and the genotyping for the fertility restoration nuclear locus (Ms) in 59 onion accessions, aiming at the selection of 'A' and 'B' lines essential for the obtainment of hybrids. Three markers were used to identify the cytoplasm 5' cob, orfA501, and orf725, and two were used for the Ms locus (AcSKP1 and AcPMS1). The two types of male-sterile cytoplasm ('S' and 'T'), as well as fertile cytoplasm ('N'), and the Ms and ms alleles in both homozygosity and heterozygosity were detected in the 59 genotypes evaluated in the experiment. The frequencies of the 5' cob/orfA501 and orf725 markers, as well as of the markers AcSKP1 and AcPMS1, were close in the onion accessions evaluated in this study. In the Brazilian germplasm, the frequencies of the 'N', 'S', and 'T' cytoplasm were approximately 0.47, 0.28, and 0.25, respectively, whereas the allele frequencies of Ms and ms were 0.52 and 0.48, respectively. The accessions Régia, EHCEB 20146, EHCEB 201427, Alvorada, Serrana, Crioula Mercosul, EHCEB 20142, BRS 367, Rainha, Juporanga, and Alfa SF C-XI have potential for the identification of 'A' and 'B' lines, since they presented mixtures of cytoplasm and different allele frequencies for Ms. All the plants of the accessions EHCEB 20142040/EHCEB 20141040, EHCEB 20142028/EHCEB 20141028, and EHCEB 20112006/EHCEB 20111006 were in the Nmsms and Smsms conditions, and have the potential for 'B' and 'A' lines, respectively, for the CMS-S system. All the plants of the accessions EHCEB 20142027/EHCEB 20141027, EHCEB 20102019/EHCEB 20101019, and Alfa SF 'B'/Alfa SF 'A' were in Nmsms and Tmsms conditions, and have the potential for 'B' and 'A' lines, respectively, for the CMS-T system.
The use of resistant cultivars is an efficient and recommended method for the management of leafminers, which are the main phytosanitary problem in melons. The objectives of this study were to identify the sources of resistance to the leafminer in yellow melon accessions and to determine the resistance inheritance in acession AM-RT. Two field experiments were conducted in the municipalities of Baraúna, RN and Icapuí, CE, Brazil, to identify the sources of resistance. The design adopted was completely randomized blocks with 22 treatments and four replications. In this evaluation, the number of mines per leaf was quantified. The heterogeneity of the studied materials allowed for the identification of the accessions AM-RT and AM-TM as sources of resistance, considering that they revealed zero mines in the two evaluation environments. The accession AM-RT was selected and used to obtain the S1 population (by self-fertilization), S1:2 population derived from S1, and crossing between AM-RT and ‘Goldex’, which were evaluated in a third laboratory trial to determine the genetic control of resistance in that material. By the segregation pattern of the populations S1, S1:2, and the crossing (AM-RT and ‘Goldex’) and the estimation of the chi-squared (χ2) values, which were 1.33, 3.14, and 0.36, respectively, it was determined that the inheritance of resistance was controlled by only one gene with complete dominance. Therefore, in this study, two sources of resistance to the leafminer were identified, and resistance was conditioned by a gene with complete dominance in the accession ‘AM-RT’.
O controle da mosca minadora Liriomyza sativae é imprescindível nas áreas de produção de melão (Cucumis melo) dos estados do Rio Grande do Norte e Ceará. Portanto, objetivou-se avaliar o efeito letal de diferentes concentrações de extrato aquoso de folhas de nim, aplicadas via pulverização sobre as folhas e via irrigação no solo, sobre larvas da mosca minadora L. sativae em meloeiro. Foram realizados dois bioensaios, sendo o primeiro mediante a aplicação via pulverização direta sobre as larvas nas folhas, e o segundo via aplicação no solo. Os bioensaios foram conduzidos em delineamento inteiramente casualizado, composto por seis tratamentos (cinco concentrações do extrato aquoso de folhas de nim: 0,0; 2,5; 5,0; 7,5; 10,0 e 12,5 g 100 mL-1 de água destilada e o tratamento controle: somente água destilada). Foram realizadas duas avaliações: na primeira, contabilizou-se o número de larvas mortas por planta, enquanto na segunda, registrou-se a mortalidade pupal. Foi verificado aumento da mortalidade larval e pupal da mosca minadora com o incremento na concentração do extrato aquoso de folhas de nim, independente da forma de aplicação. O extrato aquoso de folhas de nim é letal para larvas e pupas da mosca minadora L. sativae, independentemente da forma de aplicação. A maior concentração do extrato aquoso de nim estudada (12,5 g 100 mL-1), apesar de não ocasionar o máximo de controle, proporcionou os maiores percentuais de mortalidade de L. sativae.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.