Evidence of seed transmission of dolichos yellow mosaic virus, a begomovirus infecting lablab-bean in India

Abstract

Yellow mosaic disease in field bean caused by begomoviruses belonging to the family Geminiviridae is a major threat to the cultivation of crop in South India. Appearance of bright yellow mosaic symptom in emerging seedlings in farmers field was suggestive of seed transmission of the begomovirus associated with the disease which was investigated in the present study. The begomovirus causing yellow mosaic disease was identified as dolichos yellow mosaic virus (DoYMV) and the presence of DoYMV in matured seeds was confirmed by DAS-ELISA with OD value up to 3.268. In PCR with DoYMV specific primer (DoYMV-CP) the virus was detected in different parts of the seeds viz., seed coat, endosperm and embryo. In embryo the virus was detectable up to 100 per cent followed by endosperm (69.23%). When the non symptomatic leaves of 30 days old grow-out test plants were subjected to DAS-ELISA, the virus was detected up to 46.6%. This is the first evidence of seed transmission of DoYMV.

Keywords: Begomovirus; Dolichos yellow mosaic virus (DoYMV); ELISA; Field bean; Seed borne nature.

Fig. 1

a Field bean plant showing yellow mosaic symptom. b Detection of begomovirus in naturally infected leaf sample collected from different locations through PCR with Rojas primer (PALIc1960 and PARIv722); Lane 1—Ladder (1 kb), Amplicon with DNA extracted from; Lane 2, 3, 4—TNAU isolate (CBE1), Lane 5, 6, 7—Thondamuthur isolate (TM1), Lane 8, 9, 10—Dhaliyur isolate (DH1), Lane 11—Positive control (Infected leaf from tomato plant) and Lane 12—Negative control (Healthy uninoculated leaf from field bean plant). c Detection of DoYMV in naturally infected leaf sample collected from different locations through PCR with DoYMV-CP primer (DoYMV-CP 377F and DoYMV-CP 580R); Lane 1—Ladder (1 kb), Amplicon with DNA extracted from; Lane 2, 3, 4—TNAU isolate (CBE1), Lane 5, 6, 7—Thondamuthur isolate (TM1), Lane 8, 9, 10—Dhaliyur isolate (DH1), Lane 11—Positive control (Infected leaf from field bean plant) and Lane 12—Negative control (Healthy uninoculated leaf from field bean plant)

Fig. 2

Detection of begomovirus in yellow mosaic infected field bean leaf samples collected from different location by DAS—ELISA using ToLCNDV antiserum; Absorbance at 405 nm was recorded 30 min after adding substrate. Values presented is average of three replication. Leaf samples from tomato showing leaf curl symptoms were used as positive control. Leaf samples from uninoculated healthy field bean plants served as negative control

Fig. 3

Detection of begomovirus in seeds from infected field bean plants by DAS-ELISA using ToLCNDV antiserum; Absorbance at 405 nm was recorded 30 min after adding substrate. Leaf samples from field bean plant showing mosaic symptom was used as positive control. Leaf samples from uninoculated healthy field bean plants served as negative control

Fig. 4

Detection of DoYMV in different parts of seed through PCR using DoYMV-CP primer (DoYMV-CP 377F and DoYMV-CP 580R); Lane 1,12—Ladder (100 bp), Amplicons (200 bp) with DNA extracted from; Lane 2 to 6—CBE1 isolate, Lane 7 to 11—TM1 isolate, Lane 13 to 17—DH1 isolate, Lane 18—Positive control (Infected leaf from field bean plant), Lane 19—Negative control (Healthy uninoculated leaf from field bean plant). a Seed coat. b Endosperm. c Embryo

Fig. 5

Detection of begomovirus in leaves of grow-out test plants by DAS-ELISA using ToLCNDV antiserum; Absorbance at 405 nm was recorded 30 min after adding substrate. Leaf samples from field bean plant showing mosaic symptom was used as positive control. Leaf samples from uninoculated healthy field bean plants served as negative control

Fig. 6

Detection of DoYMV in grow-out test plants by PCR using DoYMV-CP primer (DoYMV-CP 377F and DoYMV-CP 580R); Lane 1—Marker (100 bp), Lane 2 to 11—amplicon with DNA extracted from leaf samples of grow-out test, Lane 12—Positive control (Infected leaf from field bean plant), Lane 13—Negative control (Healthy uninoculated leaf from field bean plant)