Molecular studies on transmission of mung bean yellow mosaic virus (MYMV) by Bemisia tabaci Genn. in Mungbean

Abstract

The whitefly Bemisia tabaci Genn. is an important pest worldwide because of its ability to cause damage by direct feeding and its role as a vector of plant viruses including geminiviruses. Yellow mosaic virus (MYV) is a serious disease of pulse crops including mungbean, blackgram, frenchbean, pigeonpea and soybean. Yellow mosaic diseases are one of the most important viral diseases in mungbean caused by mungbean yellow mosaic virus (MYMV) which lead to severe yield reduction and it necessitates development of MYMV resistant lines for improved crop yield. Basic studies were carried out to elucidate the characteristics of MYMV transmission by its vector, B. tabaci. Artificial transmission experiments with B. tabaci were conducted under greenhouse conditions using cylindrical nylon cages with wire mesh tops. After 24 h acquisition access period (ASP) on agroinfected mungbean plants, B. tabaci collected from these agroinfected mungbean plants were considered viruliferous and transferred to a separate cage with healthy mungbean plants as confirmed via agroinoculation. After 24 h inoculation access period (IAP), B. tabaci were removed and the plants were sprayed with an insecticide and kept for observations of symptom development for 10 to 25 days in insect cages. Studies concluded with mungbean accessions using ten whitefly adults with 24 h of ASP and IAP resulted in transmission of virus of 70.50, and percent in MYMVR 111 (At VA 221), MYMVR 29 (At VA 239) and MYMVR 29 (At VA 221) respectively. Ten viruliferous whitefly adults did not cause MYMV symptom in KMG 189 (At VA 221), ML818 (At VA 239) and MYMVR 57 (At VA 221). Twenty viruliferous whitefly adults were able to cause MYMV after 48 h ASP and 24 h IAP and resulted in the maximum transmission efficiency in MYMVR 55 (At VA 221) (85.00%) and MYMVR 55 (At VA 239) (83.50%). The virus was proven to be a persistent discrete fragment of 703 bp using the polymerase chain reaction method on viruliferous whitefly adults, while no bands were obtained from non-viruliferous B. tabaci adults reared on CO 2 brinjal host.

Yellow Mosaic Disease (YMD) of Mungbean (Vigna radiata (L.) Wilczek): Current Status and Management Opportunities

“…Whitefly is an extremely efficient vector as even a single viruliferous adult can transmit the YMV within 24 h of AAP and IAP (Malathi and John, 2009). Govindan et al (2014) reported 10 viruliferous adult whiteflies after 24 h each of AAP and IAP causing YMD with 70.50% virus transmission efficiency, while 20 viruliferous whitefly adults after 48 h of AAP and 24 h of IAP has resulted in 85% virus transmission efficiency. Since YMD can be very effectively spread by very low densities of adult whiteflies; therefore, no correlation could be established between the number of whiteflies and YMD severity (Akhtar et al, 2011).…”