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.

Large-Scale Seedling Grow-Out Experiments Do Not Support Seed Transmission of Sweet Potato Leaf Curl Virus in Sweet Potato

“…Seedlings tested in that study were initially germinated in a greenhouse, thereby allowing the possibility of whitefly presence and potential vector transmission. Based on our lack of evidence for seed transmission of SPLCV and that of TYLCV seed transmission studies [ 33 , 34 ], we suggest that those reports of seed transmission of other begomoviruses [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] be re-examined. Biological assays through the large-scale cultivation of contaminated seedlings using strict conditions excluding any possible introduction of whiteflies present in the environment (not merely testing seeds or embryos for the presence of the targeted begomovirus) will provide more robust evidence for or against seed transmission.…”

“…After this first report of begomovirus seed transmissibility, several other reports of seed transmitted begomoviruses were published, including tomato yellow leaf curl virus type strain Israel (TYLCV-IL) in tomato, pepper, and soybean by the same research group [ 23 , 24 , 25 ]. In addition, several other begomoviruses reported to be seed transmissible are bitter gourd yellow mosaic virus in bitter gourd ( Momordica charantia ) [ 26 ], tomato leaf curl New Delhi virus in chayote ( Sechium edule ) [ 27 ] and zucchini squash ( Cucurbita pepo ) [ 28 ], dolichos yellow mosaic virus in lablab-bean ( Lablab purpureus ) [ 29 ], and pepper yellow leaf curl Indonesia virus in pepper ( Capsicum annuum ) in Indonesia [ 30 ]. While those reports concluded that seed transmission of various begomoviruses occurred, the studies were typically performed using a very small number of seedlings in grow-out experiments.…”

Breeding for Enhancing Legumovirus Resistance in Mungbean: Current Understanding and Future Directions

“…Malathi and John [22] stated that viruliferous adults are In addition, many more techniques have been made available to detect the virus. Suruthi et al [12] suggested using of DAS-ELISA for detection of the virus. Based on the results of DAS-ELISA, they reported the seed-borne nature of DoYMV.…”

“…This disease currently is a major hazard to the flourishing production of mungbean in India, Sri Lanka, Pakistan, Bangladesh, Papua New Guinea, Philippines, and Thailand [6][7][8][9]. YMD was first reported in lima bean (Phaseolus lunatus) in 1940 [10] and was subsequently discovered in other plants, such as Dolichos bean (Dolichos lablab) [11,12] and mungbean [13]. It creates malformations in mungbean plants, which in turn inhibit photosynthetic efficiency and plant growth, ultimately leading to significant yield losses [7,14,15].…”

Frequent occurrence of Mungbean yellow mosaic India virus in tomato leaf curl disease affected tomato in Oman

“…The very close relationship of the isolates in Oman and Indonesia also suggests that they have a common origin, likely having been introduced from South Asia. The likely mechanism of introduction is unclear, although the demonstration for an increasing number of geminiviruses that seed transmission can occur, including for the LYMVs DoYMV 42 and possibly MYMV 43 , which are closely related to MYMIV, may suggest that the mechanism of geographic dispersal was via seed.…”