Ceratocystis Wilt in ‘Ubá’ and ‘Dura’ Mango Trees Under Water Deficit

Abstract

-The occurrence of water stress in mango trees grown in orchards located in semi-arid climates in Brazil is frequent. Water stress caused to plants may predispose them to the incidence of fungal diseases. The aim of this study was to evaluate the effect of water deficit on the incidence and severity of Ceratocystis wilt in mango trees considered resistant. Seedlings of 'Ubá' and 'Dura' were kept in pots and submitted to different water stress levels and inoculated with Ceratocystis fimbriata isolate (CEBS15). Mortality was low in 'Ubá' plants and high in 'Dura' plants. 'Ubá' plants showed lower severity and lesion length. In 'Ubá' plants, water deficit influenced the increase in lesion length. 'Dura' plants showed greater severity and lesion length, which were not affected by increasing water stress. It was concluded that 'Ubá' variety is resistant to fungus Ceratocystis fimbriata, even in severe drought conditions, while 'Dura' variety was not resistant to CEBS15 isolate, even under optimum irrigation conditions. Index terms: Mangifera indica, Ceratocystis fimbriata, stress. MURCHA-DE-CERATOCYSTIS NAS MANGUEIRAS 'UBÁ' E 'DURA' SUBMETIDAS A DÉFICIT HÍDRICORESUMO -É comum a ocorrência de estresse hídrico em mangueiras cultivadas em pomares situados em regiões de clima semiárido no Brasil. O estresse causado às plantas pode predispô-las à incidência de doenças fúngicas. O objetivo deste estudo foi avaliar o efeito do déficit hídrico na incidência e severidade da Murcha-de-Ceratocystis em cultivares de mangueiras consideradas resistentes. Mudas das mangueiras 'Ubá' e 'Dura' foram mantidas em vasos e submetidas a diferentes níveis de estresse hídrico e inoculadas com o isolado (CEBS15) de Ceratocystis fimbriata. A mortalidade das plantas foi baixa na 'Ubá' e alta na 'Dura'. 'Ubá' apresentou menores valores de severidade e comprimento de lesão. Na 'Ubá', o déficit hídrico influenciou no aumento do comprimento da lesão. A 'Dura' apresentou maior severidade e comprimento de lesão, que não foram influenciados pelo aumento de déficit hídrico. Concluiu-se que a 'Ubá' é resistente ao fungo Ceratocystis fimbriata, mesmo em condições de déficit hídrico severo, enquanto a 'Dura' não foi resistente ao isolado CEBS15, mesmo em condições ótimas de irrigação. Termos para indexação: Mangifera indica, Ceratocystis fimbriata, estresse hídrico.

Environmental and irrigation conditions can mask the effect of Magnaporthiopsis maydis on growth and productivity of maize

“…In the present study, the expression of the disease caused by M. maydis in the inoculated plants was strongly influenced by the water availability (full irrigation compared to moderate stress). Moreover, symptoms of wilting and (Ochola et al, 2015), but also in that of fungal diseases, like verticillium wilt of eggplant (Bletsos et al, 1999) or pistachio (Saadatmand et al, 2008), or ceratocystis wilt caused by Ceratocystis fimbriata in mango (Rezende da Silva et al, 2017). An important dependence of late wilt on the water status of maize has been suggested under field conditions, with decreased disease severities under flood-fallowing (Samra et al, 1966).…”