Electron Microscopy and Molecular Characterization of Phytoplasmas Associated with Little Leaf Disease of Brinjal (Solanum melongena L.) and Periwinkle (Catharanthus roseus) in Bangladesh

Abstract

In Bangladesh little leaf disease was observed in brinjal (Solanum melongena L.) and in periwinkle (Catharanthus roseus). Phloem‐inhabiting phytoplasmas were consistently detected in both species of diseased plants using transmission electron microscopy (TEM) and polymerase chain reaction (PCR) techniques. The shape, size and within‐tissue distribution of phytoplasmas appears to be similar in both hosts. Furthermore, the molecular characterization and identifications of observed phytoplasmas were carried out based on restriction fragment length polymorphism (RFLP) patterns of PCR‐amplified products (1200 bp) using phytoplasma‐specific universal primers and sequencing analysis of both 16S ribosomal DNA (rDNA) and intergenic spacer region (ISR) of 16S‐23S rDNA phytoplasma genes. The patterns of RFLP analysis with seven restriction enzymes exhibited a similar pattern for both phytoplasma strains. The sequence homology between these two strains showed 100% similarity based on 16S rDNA and 16S‐23S ISR. Therefore, in Bangladesh the causal agents of brinjal little leaf (BLL‐Bd) and periwinkle little leaf (PLL‐Bd) are probably the same or closely related phytoplasma strains. These strains, are very close or identical to the strain of brinjal little leaf phytoplasma in India (BLL‐In), belonging to the clover proliferation group (Lee et al., Int. J. Syst. Bacteriol. 48, 1153–1169, 1998; Seemuller et al., J. Plant Pathol. 80, 3–26, 1998).

Phytoplasmas and Phytoplasma Diseases: A Severe Threat to Agriculture

“…VI-B Strawberry multiplier disease (MC) AF190224 [147] VI-C Illinois elm yellows (EY-IL1) AF409069/AF409070 [175] VI-D Periwinkle little leaf (PLL-Bd) AF228053 [176] VI-E Centarurea solstitialis virescence (CSVI) AY270156 [177] VI-F Catharanthus phyllody phytoplasma (CPS) EF186819 [25] VI-H Portulaca little leaf phytoplasma (PLL-Ind) EF651786 [178] VI-I Passionfruit (WB-Br4) 'Ca. P. sudamericanum' GU292081 [165] Continued 16SrVII: Ash yellows (America, Europe)…”

Identification by computer-simulated RFLP of phytoplasmas associated with eggplant giant calyx representative of two subgroups, a lineage of 16SrIII-J and the new subgroup 16SrIII-U

“…In Japan, a phytoplasma affiliated to group 16SrI was characterized molecularly from eggplant with dwarfing symptoms (Okuda et al, 1997;Lee et al, 1998). A disease called little leaf was reported in Bangladesh and molecular identification indicated that the phytoplasma belonged to group 16SrVI (Siddique et al, 2001). The study also demonstrated the phytoplasma to be indistinguishable from brinjal little leaf (BLL) phytoplasma characterized previously in India (Lee et al, 1998; Seemüller et al, 1998).…”

“…However, the RFLP analysis conducted in that study used only some of the enzymes proposed by Lee et al (1998) and some of the techniques used today, especially sequencing and computer programs, were not then available. Although phytoplasmas of group 16SrIII have been identified as agents of eggplant giant calyx in Brazil, the same disease has been described in other countries associated with phytoplasmas belonging to other (Siddique et al, 2001) and, recently, subgroup 16SrVI-D (Wei et al, 2008). On the basis of RFLP analysis, the big bud eggplant phytoplasma found in Japan was identified as a member of group 16SrI (Okuda et al, 1997).…”

Identidade molecular dos fitoplasmas associados aos enfezamentos do tomateiro e da berinjela com base na análise do gene 16S rDNA

“…A presença de fitoplasmas associados ao enfezamento de plantas de tomate e berinjela é conhecida há algum tempo em diversos países como Estados Unidos (6, 9), Índia (26,28), Irã (24) e Israel (29). Mais recentemente, a identificação em nível molecular tem mostrado a ocorrência de diversidade de fitoplasmas associados aos enfezamentos do tomateiro.…”