Bioprospecting of citrus (Citrus L.) germplasms against citrus canker pathogenesis in Assam, North-East India

The current investigation assessed the effectiveness of 30 citrus germplasms in com
bating citrus canker pathogenesis in Assam, North-East India. Significant differences
were observed among the examined citrus germplasms in terms of per cent disease
severity and disease reduction against Xanthomonas citri pv. citri. Among the 30 dif
ferent germplasms, eight germplasms, namely, Jora tenga (14.67%), Bonjora (15.58%),
Holong tenga (15.75%), Latipes (17.34%), Patijora (17.75%), Birajora (18.50%), Cleo
patra mandarin (20.00%) and Ada jamir (20.18%), exhibited highest disease resistance
potential. The study recorded that the germplasm Latipes, which are resistant, had
the highest total phenol content (21.26 mg/g dry weight), while the susceptible one,
Grapefruit (7.85 mg/g dry weight), had the lowest total phenol content. Jora tenga
exhibited the highest flavonoid content, measuring at 6.48 mg/g dry weight, whereas
White pummelo had the lowest flavonoid content, measuring at 1.88 mg/g dry
weight. Similarly, the highest alkaloid percentage was recorded in resistant germ
plasm, Adajamir (10.52%), while the lowest was in susceptible germplasm, Volkameri
ana (2.30%). The levels of total phenol, alkaloid and flavonoid contents exhibited a
significant negative correlation with the per cent disease severity of citrus canker dis
ease in both Pearson correlation and Spearmen correlation analysis. The current
research on bioprospecting of citrus germplasms in relation to citrus canker patho
genesis has the potential to offer valuable insights into mitigating the transmission of
bacterial pathogens and eliminating sources of infection by employing resistant culti
vars and implementing approved doses of plant protection formulations.