Fusiform rust,caused by the pathogen Cronartium quercuum(Berk.)Miyabe ex Shirai f.sp.fusiforme,is the most important disease of loblolly pine(Pinus taeda L.)in the U.S.,causing millions of dollars in damage each year....Fusiform rust,caused by the pathogen Cronartium quercuum(Berk.)Miyabe ex Shirai f.sp.fusiforme,is the most important disease of loblolly pine(Pinus taeda L.)in the U.S.,causing millions of dollars in damage each year.Using resistant genotypes has proven a successful strategy to limit the disease,but resistance selection still relies on visual inspection for symptoms,which can lead to misclassification due to human error and the presence of'escaped susceptibles'(i.e.,susceptible individuals with no visible symptoms due to either an extended asymp-tomatic phase of the disease or the lack of adequate disease pressure to become infected).Here,we propose the use of near-infrared(NIR)spectroscopy and chemometrics to improve the accuracy of how phenotypes are rated.We collected and analyzed phloem and needle spectra from 34 non-related families replicated across eight stands in three states in the southeastern region of the U.S.using a portable,handheld NIR spectrometer.We also used a benchtop Fourier-transformed mid-infrared(FT-IR)spectrometer to analyze phloem phenolic extracts of the same samples,as this phenotyping approach has proved successful in other pathosystems.Our results show a moderate association between the phloem spectra and resistance,and models built with NIR spectra were able to classify extremes(i.e.,very resistant or very susceptible)with up to 69%testing accuracy.This study provides a framework for using NIR spectroscopy for phenotyping loblolly pine resistance against pathogens and advocates for using alternative technologies in forestry.展开更多
基金This research was funded by the United States Forest Service,Forest Health Protection Special Technology Development Program(grant number 20-DG-11083150-003)the Southern Pine Health Research Cooperative(SPHRC)at the University of Georgia(Athens,Georgia,United States).
文摘Fusiform rust,caused by the pathogen Cronartium quercuum(Berk.)Miyabe ex Shirai f.sp.fusiforme,is the most important disease of loblolly pine(Pinus taeda L.)in the U.S.,causing millions of dollars in damage each year.Using resistant genotypes has proven a successful strategy to limit the disease,but resistance selection still relies on visual inspection for symptoms,which can lead to misclassification due to human error and the presence of'escaped susceptibles'(i.e.,susceptible individuals with no visible symptoms due to either an extended asymp-tomatic phase of the disease or the lack of adequate disease pressure to become infected).Here,we propose the use of near-infrared(NIR)spectroscopy and chemometrics to improve the accuracy of how phenotypes are rated.We collected and analyzed phloem and needle spectra from 34 non-related families replicated across eight stands in three states in the southeastern region of the U.S.using a portable,handheld NIR spectrometer.We also used a benchtop Fourier-transformed mid-infrared(FT-IR)spectrometer to analyze phloem phenolic extracts of the same samples,as this phenotyping approach has proved successful in other pathosystems.Our results show a moderate association between the phloem spectra and resistance,and models built with NIR spectra were able to classify extremes(i.e.,very resistant or very susceptible)with up to 69%testing accuracy.This study provides a framework for using NIR spectroscopy for phenotyping loblolly pine resistance against pathogens and advocates for using alternative technologies in forestry.
