Screening a variable germplasm collection of Cucumis melo L. for seedling resistance to Macrophomina phaseolina

Abstract

reported to be useful for predicting shoot resistance, were performed, and plants were scored using a scale of disease severity. The average disease severity was calculated for each accession and was used to cluster the accession in five reaction classes. The screening revealed that sources of natural resistance to this fungus are limited. However, seedlings of seven accessions of different botanic groups displayed a resistant response to the stem inoculation, one cantaloup from Israel, one conomon accession from Korea, two wild agrestis and one acidulus from Africa, and two dudaim accessions from Middle East. The response of the F1 progenies varied from susceptibility to high resistance, the latter in progenies from the two agrestis wild types. These results suggest differences in the genetic basis of the resistance in the different selected sources. The resistant accessions are suggested to be screened under field conditions to confirm the level of resistance at adult plant stage and under stressful conditions.

Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in Northeastern Brazil

“…The inoculation technique used was the toothpick method, because of the easy multiplication of inoculum and fast inoculation (Ambrósio et al, ; Medeiros et al, ; Mir et al, ). Twelve mm long toothpicks were placed, with the sharpened end up, in holes made in a 90‐mm‐diameter filter paper.…”

Reaction of melon genotypes to Didymella bryoniae (Fuckel) Rehm

“…However, there are no reports of studies using a full-scale reaction. Therefore, the present study suggested a modified scale, which has been used in studies with other soil-borne pathogens, such as Myrothecium roridum (Noronha et al, 2006), Rhizoctonia solani (Michereff et al, 2008) and Macrophomina phaseolina (Ambrósio et al, 2015).…”

Análise de ligação do gene de resistência <i>Zym-2</i> com marcadores microssatélites e reação de acessos de meloeiro ao <i>Zucchini yellow mosaic virus</i> (ZYMV)

“…A média das leituras de absorbância foi utilizada como medida quantitativa de são moderadamente resistentes a esse fungo (AMBROSIO et al, 2015). Portanto, esses acessos brasileiros possuem grande potencial de uso no melhoramento.…”

“…O Brasil é um dos maiores produtores de melão da América do Sul e produziu 575 mil t em 2012, atingindo a nona posição no ranking mundial (FAOStat, 2015). A região Nordeste domina a produção de melão no país (MOURA et al, 2011;DANTAS et al, 2015).…”

“…Esse vírus foi encontrado no Brasil nas culturas da melancia em São Paulo e do pepino em Santa Catarina, no início da década de 90 (KUROZAWA et al, 2005). A incidência de ZYMV aumentou no país ao longo dos anos e o vírus provavelmente já está presente em todos os estados brasileiros (YUKI et al, 2000;MOURA et al, 2001;HALFELD-VIEIRA et al, 2004;SILVEIRA et al, 2009;SPADOTTI, 2012 No Brasil, a produção é baseada em cultivares híbridas pertencentes aos grupos Inodorus e Cantalupensis, que se incluem na subespécie melo (DANTAS et al, 2015). As cultivares do grupo Inodorus, representadas pelos tipos "Amarelo", polpa alaranjada e Pele de Sapo são as preferidas pelos produtores (NUNES et al, 2005).…”