Characterization of A New Almond Witches’ Broom Phytoplasma in Iran

Abstract

Almond witchesÕ broom (AlmWB) is a destructive disease in several provinces in Iran. Association of phytoplasma with the disease has been established previously. In the present work two phytoplasmas from Khafr (KAlmWB) and Neyriz (NAlmWB) in the Fars Province were compared by biological and molecular analysis. Both infected bitter almond, wild almond, peach and nectarine but not apple and pear, by grafting. In bitter almond the symptoms induced by KAlmWB consisted of severe proliferation, internode shortening and leaf size reduction. In contrast, NAl-mWB caused leaf necrosis, dieback and death. KAlmWB was transmitted to periwinkle and eggplant and from experimentally infected periwinkle to almond by dodder. It was also transmitted from eggplant to eggplant, ornamental eggplant and tomato by grafting. Under similar test conditions, NAlmWB was not transmitted to herbaceous plants by dodder. Phylogenetic analysis of 16S-23S rDNA spacer region (SR) sequences placed both strains in the pigeon pea wit-chesÕ broom (PPWB) group. However, based on phylogenetic and putative restriction site analyses and sequence homology, NAlmWB was identical with the Lebanese AlmWB phytoplasma, while KAlmWB was closer to the Knautia arvensis phyllody (KAP) agent. Clustering of KAlmWB with KAP was confirmed by analysis of full length 16S rDNA sequence. On the basis of host range, dodder transmission, host range, symptomatology and molecular analyses of 16S rDNA and SR, two different phytoplasmas related to PPWB group were associated with AlmWB disease in Iran. KAlmWB phytoplasma is being reported as a new phytoplasma of AlmWB disease. Graft inoculationOne-year-old seedlings of fruit trees and 8-week-old herbaceous plants were used as test indicators and grafted with small auxillary shoots from infected or www.blackwell-synergy.com

Molecular Study of a New Disease of Peach in Iran Associated with a Phytoplasma

“…Phytoplasma phoenicium" [15,16]. In this study, we showed that a phytoplasma is associated with peach yellows symptoms in Kurdistan province of Iran that showed 98% sequence homology with almond witches' broom phytoplasma, "Ca.…”

“…Almond witches' broom has been reported as a widespread and devastating disease in Iran and Lebanon [16,17]. It can spread rapidly and kill trees at any age within 2 -3 years [17] and transmitted by dodder to peach and nectarine trees in greenhouse condition [16,17].…”

“…It can spread rapidly and kill trees at any age within 2 -3 years [17] and transmitted by dodder to peach and nectarine trees in greenhouse condition [16,17]. We have previously reported that almond witches broom phytoplasma is present in all almond important growing area in Iran [18].…”

Molecular Characterization and Phylogeny of a Phytoplasma Associated with Phyllody Disease of toria (Brassica rapa L. subsp. dichotoma (Roxb.)) in India

“…There are only two other phytoplasma in this sub group viz. phytoplasma associated with K. arvensis phyllody in Italy [18] and almond witches'-broom in Iran [21]. The 23S rRNA gene has not been sequenced completely for most of the phytoplasmas [10,12].…”

Identificação de fitoplasmas associados à síndrome do amarelecimento foliar da cana-de-açúcar e ao superbrotamento de primavera (Bougainvillea spectabilis) no estado de São Paulo

“…Em plantas lenhosas, como é o caso da primavera, é comum a ocorrência de infecção com baixo título de fitoplasma, como já registrado para outras espécies como Rubus fruticosus , olmo (Ulmus spp) , macieira (KARTTE; SEEMUELLER, 1991), e videira (CREDI, 1994 Uma vez que os fitoplasmas não são cultiváveis em meio de cultura, a cuscuta tem se mostrado útil nos trabalhos envolvendo este tipo de patógeno. A transmissão destes agentes de plantas doentes para plantas sadias é um das formas de se demonstrar a sua patogenicidade e confirmar diagnoses feitas com base na sintomatologia, como tem sido relatado em diversos trabalhos (COUSIN et al, 1986;CARRARO et al, 1988;CARRARO et al, 1991;CREDI;SANTUCCI, 1992;LOI et al, 1995;SEEMULLER, 1997;SALEHI;IZADPANCH;HEYDARNEJAD, 2006). A transmissão de fitoplasmas a partir de seu hospedeiro original para plantas de vinca através da cuscuta também tem sido utilizada quando estes fitoplasmas ocorrem em baixas concentrações, pois a sua passagem para vinca pode facilitar sua detecção, bem como servir para a manutenção de coleções de fitoplasmas para uso futuro (MARCONE et al, 1999).…”