Using VIS-NIR spectroscopy and multi-omics analysis to compare mango anthracnose under natural and inoculated

Ye Sun1, Diandian Liang1, Dandan Zhou2

  • 1College of Food Science and Light Industry, Nanjing Technology University, Nanjing 211816, China.

Insights

Mango anthracnose detection using optical technology differs between inoculated and natural infections. Natural infections show greater microbial diversity and unique spectral signatures, suggesting inoculation is not a perfect substitute for lab research.

Area of Science:

  • Agricultural science
  • Plant pathology
  • Spectroscopy

Background:

  • Optical technology is widely used for detecting mango anthracnose, often relying on artificial inoculation methods.
  • The representativeness of inoculated infections (InI) versus naturally infected diseases (NaI) in mangoes remains unclear.
  • Understanding these differences is crucial for developing accurate, non-destructive detection techniques.

Purpose of the Study:

  • To systematically compare microbial communities, metabolite profiles, and VIS-NIR spectral characteristics of InI and NaI mango anthracnose.
  • To evaluate the reliability of InI as a substitute for NaI in laboratory research for optical detection.
  • To identify key spectral differences and assess the accuracy of optical detection models for both infection types.

Main Methods:

  • Comparative analysis of microbial community composition using sequencing.
  • Metabolomic profiling to identify differential metabolites.
  • Visible Near-Infrared (VIS-NIR) spectroscopy (400-1000 nm) for spectral characteristic analysis.
  • Partial Least Squares Discriminant Analysis (PLS-DA) for classification accuracy.

Main Results:

  • Distinct microbial compositions were observed: InI was dominated by Colletotrichum-xanthorrhoeae (99.6%), while NaI showed higher diversity with C. xanthorrhoeae (66.7%) and Botryosphaeria agaves (32.9%).
  • Metabolomic analysis revealed 255 differential metabolites, with only three shared among the top 20, indicating significant biochemical variations.
  • Early-stage spectral analysis showed unique effective wavelength regions: InI at 786-798 nm and NaI at 631-637 nm, linked to metabolite and pigment differences.
  • PLS-DA models achieved 100% accuracy for early InI detection but 89.92% for early NaI detection.

Conclusions:

  • Inoculation methods do not fully replicate the complex physiological and biochemical characteristics of natural mango anthracnose infections.
  • Significant differences in microbial communities, metabolite profiles, and spectral signatures exist between InI and NaI.
  • Natural disease models are essential for developing robust and accurate non-destructive optical detection techniques for mango anthracnose.