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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #326418
Title: Genome-wide association mapping of soybean chlorophyll traits based on canopy spectral reflectance and leaf extracts

Author
item DHANAPAL, ARUN - University Of Missouri
item Ray, Jeffery - Jeff
item SINGH, SHARDENDU - University Of Missouri
item HOYOS-VILLEGAS, VALERIO - Michigan State University
item Smith, James - Rusty
item PURCELL, LARRY - University Of Arkansas
item FRITSCHI, FELIX - University Of Missouri

Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2016
Publication Date: 8/4/2016
Citation: Dhanapal, A.P., Ray, J.D., Singh, S.K., Hoyos-Villegas, V., Smith, J.R., Purcell, L.C., Fritschi, F.B. 2016. Genome-wide association mapping of soybean chlorophyll traits based on canopy spectral reflectance and leaf extracts. Biomed Central (BMC) Plant Biology. 16:174-189.

Interpretive Summary: Chlorophylls are green pigments that play a critical role in photosynthesis. A better understanding of the genetic basis of chlorophyll in soybean might contribute to improving photosynthetic capacity and yield in regions with adverse environmental conditions. A collection of 332 soybean lines was grown in two years and total leaf carotenoid content was determined using three different methods. One method was biochemical based and the other two methods were based on canopy spectral reflectance measurements. An association mapping approach was employed and a total of 52 molecular markers showed a significant association with total carotenoid content in at least one of the three approaches. These markers likely tagged 27 different locations in the soybean genome that have an effect on chlorophyll content. The results demonstrated markers for chlorophyll traits can be identified in soybean using both biochemical-based and canopy spectral reflectance-based measurements, and confirm that high-throughput canopy spectral reflectance measurements can be used for association mapping.

Technical Abstract: Chlorophyll is one of the major components of chloroplasts and a better understanding of the genetic basis of chlorophyll in soybean [Glycine max (L.) Merr.] might contribute to improving photosynthetic capacity and yield in regions with adverse environmental conditions. A collection of 332 diverse soybean genotypes were grown in two years (2009 and 2010)and chlorophyll a (eChl_A), chlorophyll b (eChl_B), chlorophyll a/b ratio (eChl_R) and total chlorophyll (eChl_T) were determined by extraction and spectrometric determination of their content (µg cm-2)in leaf tissues. Total chlorophyll was also derived from canopy spectral reflectance measurements using a model of wavelet transformed spectra (tChl_T) as well as with a spectral reflectance index (iChl_T). A genome-wide associating mapping approach wasemployed using 31,253 single nucleotide polymorphisms (SNPs) to identify loci associated with the extract based eChl_A, eChl_B, eChl_R and eChl_T measurements and the two canopy spectral reflectance-based methods (tChl_T and iChl_T). A total of 23 (14 loci), 15 (7 loci) and 14 SNPs (10 loci) showed significant association with eChl_A, eChl_B and eChl_R respectively. A total of 52 unique SNPs were significantly associated with total chlorophyll content based on at least one of the three approaches (eChl_T, tChl_T and iChl_T) and likely tagged 27 putative loci for total chlorophyll content, four of which were indicated by all three approaches. Results presented here show that markers for chlorophyll traits can be identified in soybean using both extract-based and canopy spectral reflectance-based phenotypes, and confirm that high-throughput phenotyping-amenable canopy spectral reflectance measurements can be used for association mapping.