j. indexing ofviruses ofpolyhousegrown ... ... capsicum annuum (bell pepper) viruses in conjugated...
Post on 14-Apr-2020
Embed Size (px)
Indian J. Agric. Res.. 38 (3) : 157 - 163. :~004
INDEXING OF VIRUSES OF POLYHOUSE GROWN CAPSICUM (CAPSICUM ANNUUM L.) IN PUNE - CAUSING
SEVERE SYMPTOMS AND EPIPHYrOSIS Raj Verma, S.J. Singh, R.K. Singh and Satya Pr~kash
IARI Regional Station. -' Agricultural College Estate. Shivajinagar. Pune . 411 005. India
ABSTRACT Surveys of polyhouse grown Capsicum in Pune for virus diseases was carried during 2000-
2001. A variety of symptoms were observed in these polyhouse grown Capsicum plants. The common symptoms observed were: stunting, general yellowing of plants, leaf deformation, reduced size of newly developed leaves, systemic mosaic mottling, vein-banding, vein clearing, blistering and filiform leaves. Symptoms on fruit were reduction in size, discolouration, str_ and blistering. Occurrence of four viruses viz., cucumber mosaic cucumovirus (CMV), PotatOV (PVY), tobacco etch (TEV) and pepper veinal mottle (PVMV) potyviruses were recorded on the basis of symptom diagnosis, mechanical transmission, reaction on selected test plants and serological relationship by DAS-EUSA, The most prevalent virus was CMV followed by PVY, PVMV and TEV. The study also revealed that these viruses could infect Capsicum plants alone or in combination. PVMV and TEV were detected for the first time in Capsicum from Maharashtra.
INTRODUCTION abnormal discolouration on their surface. The One of the major constraints to the samples collected were used subsequently to
production of pepper, which is an economically inoculate healthy seedlings of C. annuum cv. important crop in India, is infection by viruses. California Wonder. Mechanical transmission There are about 10 different viruses reported . was done by using chilled potassium phosphate to infect pepper in India. The virus complex buffer O.lM, pH 7.2. These were rraintained causes serious economic loss to the growers under insect proof glasshouse for symptom affecting both yield and fruit quality. expressions. Further, the isolates were Identification of the virus is imperative, if control inoculated to a set of test plants to group the measures are to be effective. In the present virus. The presence of virus in the samples was paper, we report the occurrence of potato virus "s.c0 determined using the Double antibody
~dwich Enzyme Linked Immunosorbent Y (PVY), tobacco etch virus (TEV), pepper A:ssay (DAS-ELISA). Briefly, the coating veinal mottle virus (PVMV), potyviruses and antibody were diluted 1: 100 in coating buffer ~\lcumber mosaic virus (CMV) cucumovirus in and loaded on ELISA plates. Test samples
,\polyhouse grown.Capsicum in Pune. diluted 1:10 in coating buffer, pH 9.6, were MATERIAL AND METHODS added to wells of ELISA plates and incubated To determine the prevalence of overnight at 4°C. Goat antirabbit IgG
Capsicum annuum (bell pepper) viruses in conjugated antibodies diluted in conjugate polyhouse, a survey was undertaken in and buffer, was added to the plate and incubated in around Pune during 2000. Survey was the wells for 2 hrs at 37°C. Enzyme substrate conducted during the mid-developmental stage p-nitrophenyl phosphate (Sigma) was added in of the plants. Plants were randomly evaluated 10% diethanolamine at pH 9.8. Antisera based on symptoms thought to be caused by against CMV, TEV and PVMV were purchased virus infection such asthlorosis, vein-clearing, from Bio-Red Labs Pvt. Ltd., India and of PVY mosaic, mottling, leaf malformation and fruits was obtained from IARI, New Delhi. Virus that were smaller and malformed and showed positive and negative controls were included
158 INDIAN JOURNAL OF AGRICULTURAL RESI;:ARCH
in all tests. Colour reaction was noted and sample was considered virus positive, if the reaction was greater than two times of healthy. plant extract.
RESULTS AND DISCUSSION The survey conducted in polyhouse,
revealed the occurrence of Capsicum virus diseases. Based on the reaction on selected test plants and identification through ELISA, presence of sap transmissible virus isolates of PVY, TEV, PVMV and CMV was established (Table 1).
Mosaic, dark green vein-banding and mottling were prominent symptoms on leaves of Capsicum plants infected by PVY (Fig. 1). Young leaves show crinkling and fruit formed were reduced in size. The virus isolate gave localized reaction on Chel1opodium amaranticoJor and systemic symptoms on Nicotiana tabacum, N: tabacum cv. White Burley, Datura meteJ, Lycopersicon escuJentum, Nicandra physaJoides, N. gJutinosa, Petunia hybrida and Physalis fJoridana (Table 2). The virus isolate resembled in symptomatology and host range with those described by Bidari and Reddy (1990) and Green and Kim (1998) in chilli. The symptoms on the plants infected with CMV consisted of mosaic with systemic puckering and blistering and various types of leaf distortions mainly exhibited by filiform leaf lamina (Fig. 2). Infected plants exhibited marked stunting in growth and severe reduction in size of leaves and fruits. The surface of the fruits were broken into warty swellings and were therefore frequently distorted (Fig. 3). These symptoms resembled those described by Anjaneyulu and Apparao, (1967), Lokhart and Fischer, (1976), Kaper and Waterworth (1981). The virus isolate produced chlorotic local lesions on Chenopodium amaranticoJor and systemic mosaic on Nicotiana tabacum cv. White Burley, Nicotiana gJutinosa, Cucumu sativus, Datura stramonium, D. meteJ, L. esculentum, N. physaJoides, N.
gJutinosa and P. fJoridana (Table 2). The host range of the virus isolate is closely related with those CMV reported by Bidari and Reddy (1990).
Capsicum plants infected with PVMV show initial vein-clearing, mosaic mottling, leaf malformation and reduction of leaf size (Fig. 4). Plants were much stunted with shortened internodes. Fruits on infected plants were streaked of mottled with areas of lighter green and were sometimes distorted (Fig. 5). The host range of the isolate consisted of local lesions hosti.e.,c. amaranticoJar and systemic hosts as Lycopersicon escuJentum, N. gJutinosa, N. tabacum cv. White Burley and Petunia hybrids (Table 2). The isolate resembled in symptoms to those described earlier by Brunt and Kenten . (1971), Brunt etaJ. (1978), Prasada Rao (1976) and Bidari and Reddy (1990) on chilli.
The characteristic symptoms.of TEV on Capsicum plants were prominent vein- clearing on young leaves followed by mild chlorosis and cupping of leaves. Older leaves show greenvein-banding along the veins at the base of the lamina (Fig. 6). Fruits of infected plants were small, showed line patterns. These symptoms agrees with the strain of TEV reported earlier (Greenleaf, 1953,1956; Mc Keen, 1954; Bidari and Reddy, 1986) in CapsiCum. The isolate produced necrotic local lesions on C. amaranticoJorand gave systemic reactions on Datura meteJ and D. stramonium, L. esculentum, N. physaJoides, N. gJutinosa, N. tabacum and P. fJoridana (Table 2). The isolate resembled closely with TEV as reported by Bidari and Reddy (1990),
The incidence of symptomatic plants varied largely in polyhouses. Of the four viruses tested, CMV and PVY were found in 80-85% and 70-72% of the plants respectively. PVMV was detected in 54% and whereas TEV was found in 10% of the plants surveyed. Double virus infection was d~tected in 50% of all samples that tested positive of DAS-ELISA.
Vol. 38. No.3. 2004
Table 1. Viruses detE!cted by DAS-ElISA in p6lyhouse grown Capsicum S.No. Viruses Serological reactions
1. P\fY + + 2. CMV + + + 3. TEV + + 4. PVMV + + 5. CMV + PVMV + +. + + 6. CMV+PVY + +. + 7. PVY+PVMV +. + + 8. CMV + PVMV + TEV +. + +. +
+ = Mild reaction, + + =Strong reaction. + + + = Very strong reaction.
Table 2. Symptoms of viruses detected in polyhouse grown Capsicum on diagnostic host species
Indicator plant Viruses------------------- PVY CMV TEV PVMV
Chenopodhan amaranticoJor II Nll II II Nicotiana gJutinosa MM MM. Def. MM MM Nicotiana tabacum cv. White Burley MM MM VC. MM. LD Cll Datura mete! MM.LD MM.LD VC.MM D. stramonium MM.Def. MM. Rt. St. Lycopersicon escuJentum MM MM. Def. mM.lD MM Cucumis sativus M Vigna unguiculata Nll Capsicum annuum cv. California Wonder GVB.MM MM. LD. Fl " VC. mM. Cu VC. MM. lM C. frutescens L. cv. Tabasco VC.MM MM TN MM.LD Nicandra physaloides Nll, MM MM.LD mM Petumia hybrida MM MM MM Physalis floridana Nll.MM MM mM
Cll Chlorotic local lesions, Def. Deformity, MM Mosaic mottle Nll Necrotic local lesions. St. Stunting VC Vein clearing FL Filiform leaves Cu Cupping. LD leaf distortion. mM Mild mosaic Rt Rat tailing. TN Top necrosis, GVB Green vein banding, lM leaf malformation.
Among double infected plants, 45% were Capsicum has also been observed by Alegbejo infected with CMV and PVMV, the most (1999), George eta/. (1995), Abdalla et a/. frequently detected viruses in the samples. (1991). Triple infection involving different Double infection with CMVand PW and PW combinations with ail viruses detected in these and PVMV was also observed to low surveys was found in only 8 samples. A percentage. Double infection of viruses in significantly percentage of samples from
160 INDIAN JOURNAL OF AGRICULTURAL RESEARCH
Fig. 1. Capsicum leaves infected with potato virus Y (PVY) showing mosaic and dark green vein-banding
Fig. 2. Capsicum twig showing filiform leaves due to cucumber mosaic virus (CMV) infection rr
Vol. 38. No.3, 2004
Fig. 3. Capsicum fruits infected with CMV showing deformation
Fig. 4. Pepper veinal mottle virus infected (.apsicum leaves showing mosaic and mottlmg
INDIAN JOURNAL OF AGRICULTURAL RESEARCH