Blackgram (Vigna mungo [L.] Hepper) is susceptible to some of the most destructive diseases worldwide, including the yellow mosaic disease (YMD) and leaf crinkle disease (LCD). The development of resistant or tolerant varieties is an economical and long-term solution for controlling these diseases. This study visually assessed the response of 72 blackgram genotypes against the YMD and LCD under natural field conditions for two consecutive years. Seven genotypes proved resistant to the YMD, whereas 20 were resistant to the LCD. It was also evident that four genotypes, namely, 32596, 35678, Accession-4, and Accession-7, remained resistant to both diseases during both years. Therefore, the study suggests these genotypes’ use could be beneficial in breeding programs to breed multiple-disease-resistant or tolerant blackgram genotypes or could be recommended varieties for general cultivation following adaptation to different agro-climatic areas. Further verification of the virus involved in the YMD complex had the infected leave samples tested with virus-specific primer pairs of the mungbean yellow mosaic virus (MYMV), the mungbean yellow mosaic India virus (MYMIV), and the horsegram yellow mosaic virus (HgYMV). An amplification of approximately ~2700 bp resulted in all samples only with a full-length component of the DNA-A of MYMIV, the first time confirming the association of the YMD complex in blackgram in Pakistan with the MYMIV.

Keywords: Blackgram (V. mungo L.), germplasm, evaluation, virus, diseases

Key findings: Seven blackgram (V. mungo L.) genotypes emerged resistant to the YMD, and 20 were resistant to the LCD. However, among these, four genotypes (32596, 35678, Accession-4, and Accession-7) remained resistant against both diseases. The study succeeded in being the first to report the mungbean yellow mosaic India virus (MYMIV) to cause the YMD complex in blackgram in Pakistan.