Genetic Divergence Among Cotton Genotypes Grown in the Main Season and Off Season

Abstract

-The objective of this work was to evaluate the agronomic performance and estimate the genetic divergence of 18 cotton genotypes grown in the main season (sowed in December, 2012) and off season (sowed in January, 2013), considering their agronomic characteristics and resistance to Ramularia leaf spot. A randomized block experimental design was used, with five replications. The characteristics evaluated were plant height, first branch height, position of first fruiting branch, height of first fruiting branch, length between nodes, number of nodes, average number of bolls per plant, average boll weight, area under the disease progress curve (AUDPC) related to the Ramularia leaf spot severity, weight of 100-seed from the plant middle third, fiber percentage, average production per plant, yield and cotton fiber quality. The results were subjected to individual and joint analysis of variance and the genetic divergence was estimated according to multivariate procedures (Mahalanobis' generalized distance and Tocher's optimization method). The dissimilarity matrices were summed to estimate the genetic divergence, considering both growing periods. Genetic variability was found among the genotypes evaluated, in both the main season and off season. The characteristic that most contributed to the genetic divergence in the main season was the production per plant and, in the off season, was the fiber percentage. According to the results of the present work, the crosses between the genotypes BRS- 335 and FMT-707; FM-910 and FMT-707; and IMA-08-12427 and FMT-707 are recommended.

Adaptability and Stability of Cotton Genotypes Regarding Fiber Yield and Quality Traits

“…These last two were also recommended in a generalized way and for favorable environments. These cultivars have high genetic distance based on agronomic traits and fiber quality (Gilio et al, 2017), which allows transgressive genotypes for lint yield to be selected for FY. These cultivars have high genetic distance based on agronomic traits and fiber quality (Gilio et al, 2017), which allows transgressive genotypes for lint yield to be selected for FY.…”

“…Results demonstrate that the genotypes IMA CV 690 and DP 555 BGRR are the closest to the hypothetical ideal genotype defined by Verma et al (1978), meaning they present good yield in unfavorable environments and are responsive to improvements in the environments. These cultivars have high genetic distance based on agronomic traits and fiber quality (Gilio et al, 2017), which allows transgressive genotypes for lint yield to be selected for FY.…”

Competição de variedades de algodão herbáceo para cultivo no agreste pernambucano

“…O melhoramento genético do algodoeiro no Nordeste brasileiro destaca como prioridade a obtenção de cultivares produtivos, que sejam resistentes a pragas e doenças, que sejam adaptados às condições edafoclimáticas da região, e que possuam fibras especiais, finas, resistentes e que possuam várias colorações (ECHER et al, 2010;GILIO et al, 2017).…”

Análise da divergência genética em cultivares de milho verde com e sem uso de Azospirillum brasilense

“…As medidas de dissimilaridade genética, estimadas a partir da distância de sem Azospirillum). Combinações que resultam em maiores distâncias representam genótipos que são oriundos de bancos de germoplasma distintos, e menores distâncias, os materiais que provavelmente são do mesmo banco de germoplasma (COELHO et al, 2019;DARONCH et al, 2019;GILIO et al, 2017;NERE et al, 2021;SANTOS et al, 2018;SANTOS et al, 2019;SILVA et al, 2019a;SILVA et al, 2019b).…”