Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize
Lysine and tryptophan, two essential amino acids, are generally deficient in normal maize but enriched in opaque2 (o2) mutants. However, these o2 mutants are linked to undesirable effects like soft endosperm and yield loss. To circumvent this, researchers introgressed o2 modifiers (Mo2s) into mutant...
Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-05-01
|
| Series: | Frontiers in Plant Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2025.1553512/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849715760254943232 |
|---|---|
| author | Diksha Jasrotia Sushil Kumar Yashmeet Kaur Yashmeet Kaur Abhijit Kumar Das Alla Singh Dharam Paul Shanu Shukla Priti Sharma Sujay Rakshit Ramesh Kumar |
| author_facet | Diksha Jasrotia Sushil Kumar Yashmeet Kaur Yashmeet Kaur Abhijit Kumar Das Alla Singh Dharam Paul Shanu Shukla Priti Sharma Sujay Rakshit Ramesh Kumar |
| author_sort | Diksha Jasrotia |
| collection | DOAJ |
| description | Lysine and tryptophan, two essential amino acids, are generally deficient in normal maize but enriched in opaque2 (o2) mutants. However, these o2 mutants are linked to undesirable effects like soft endosperm and yield loss. To circumvent this, researchers introgressed o2 modifiers (Mo2s) into mutant maize and developed Quality Protein Maize (QPM). This study identifies genomic regions linked to Mo2 governing kernel hardness, opacity, and tryptophan content. Two QPM lines (DQL 2104–1 and DQL 2034), contrasting for these traits, were crossed to develop a 138 F2 and 109 F2:3 mapping population. Genotyping with 141 informative SSR markers resulted in 2417.01 cM genetic map with an average marker distance of 20.66 cM between markers. Inclusive composite interval mapping (ICIM) detected 11 QTLs across six different chromosomes: seven QTLs for kernel opacity (chromosomes 1, 2, 4, 7), three for hardness (chromosomes 7, 8, 9), and one for tryptophan (chromosome 9). These QTLs co-localized with candidate genes (opaque1, opaque11, floury1, floury2, floury4, mucronate1, and waxy1). The identified QTLs provide foundational targets for marker-assisted breeding. Few QTLs like qHRD9.1 (PVE = 14.18%) and qTRP9.1 (PVE = 10.69%) are prime candidates for improving hardness and tryptophan. These loci can be pyramided into elite lines using SSR markers; genomic selection could be used to optimize trait stacking. Future fine-mapping and functional studies will refine these regions, accelerating the development of high-yielding QPM with vitreous kernels and enhanced nutritional quality. |
| format | Article |
| id | doaj-art-cf3c14cf03d44df2bdbeafe4edd3f836 |
| institution | DOAJ |
| issn | 1664-462X |
| language | English |
| publishDate | 2025-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj-art-cf3c14cf03d44df2bdbeafe4edd3f8362025-08-20T03:13:13ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2025-05-011610.3389/fpls.2025.15535121553512Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maizeDiksha Jasrotia0Sushil Kumar1Yashmeet Kaur2Yashmeet Kaur3Abhijit Kumar Das4Alla Singh5Dharam Paul6Shanu Shukla7Priti Sharma8Sujay Rakshit9Ramesh Kumar10Plant Breeding and Genetics, Punjab, Agricultural University, Ludhiana, Punjab, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaDepartment of Agricultural Botany, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaPlant Breeding and Genetics, Punjab, Agricultural University, Ludhiana, Punjab, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Agricultural Biotechnology, Ranchi, Jharkhand, IndiaIndian Council of Agricultural Research (ICAR)-Indian Institute of Maize Research, Ludhiana, Punjab, IndiaLysine and tryptophan, two essential amino acids, are generally deficient in normal maize but enriched in opaque2 (o2) mutants. However, these o2 mutants are linked to undesirable effects like soft endosperm and yield loss. To circumvent this, researchers introgressed o2 modifiers (Mo2s) into mutant maize and developed Quality Protein Maize (QPM). This study identifies genomic regions linked to Mo2 governing kernel hardness, opacity, and tryptophan content. Two QPM lines (DQL 2104–1 and DQL 2034), contrasting for these traits, were crossed to develop a 138 F2 and 109 F2:3 mapping population. Genotyping with 141 informative SSR markers resulted in 2417.01 cM genetic map with an average marker distance of 20.66 cM between markers. Inclusive composite interval mapping (ICIM) detected 11 QTLs across six different chromosomes: seven QTLs for kernel opacity (chromosomes 1, 2, 4, 7), three for hardness (chromosomes 7, 8, 9), and one for tryptophan (chromosome 9). These QTLs co-localized with candidate genes (opaque1, opaque11, floury1, floury2, floury4, mucronate1, and waxy1). The identified QTLs provide foundational targets for marker-assisted breeding. Few QTLs like qHRD9.1 (PVE = 14.18%) and qTRP9.1 (PVE = 10.69%) are prime candidates for improving hardness and tryptophan. These loci can be pyramided into elite lines using SSR markers; genomic selection could be used to optimize trait stacking. Future fine-mapping and functional studies will refine these regions, accelerating the development of high-yielding QPM with vitreous kernels and enhanced nutritional quality.https://www.frontiersin.org/articles/10.3389/fpls.2025.1553512/fullQTL mappingquality protein maize (QPM)o2 endosperm modifierskernel opacitykernel hardnesstryptophan content |
| spellingShingle | Diksha Jasrotia Sushil Kumar Yashmeet Kaur Yashmeet Kaur Abhijit Kumar Das Alla Singh Dharam Paul Shanu Shukla Priti Sharma Sujay Rakshit Ramesh Kumar Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize Frontiers in Plant Science QTL mapping quality protein maize (QPM) o2 endosperm modifiers kernel opacity kernel hardness tryptophan content |
| title | Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize |
| title_full | Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize |
| title_fullStr | Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize |
| title_full_unstemmed | Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize |
| title_short | Identification of QTLs associated with opaque2 modifiers influencing kernel opacity, kernel hardness, and tryptophan content in quality protein maize |
| title_sort | identification of qtls associated with opaque2 modifiers influencing kernel opacity kernel hardness and tryptophan content in quality protein maize |
| topic | QTL mapping quality protein maize (QPM) o2 endosperm modifiers kernel opacity kernel hardness tryptophan content |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2025.1553512/full |
| work_keys_str_mv | AT dikshajasrotia identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT sushilkumar identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT yashmeetkaur identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT yashmeetkaur identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT abhijitkumardas identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT allasingh identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT dharampaul identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT shanushukla identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT pritisharma identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT sujayrakshit identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize AT rameshkumar identificationofqtlsassociatedwithopaque2modifiersinfluencingkernelopacitykernelhardnessandtryptophancontentinqualityproteinmaize |