High-density Mapping for Gray Leaf Spot Resistance using Two Related Tropical Maize RIL Populations [post]

Long Chen, Li Liu, Ziwei Li, Yudong Zhang, Manjit S Kang, Yunyue Wang, Xingming Fan
2021 unpublished
The identification of QTL/genes to resist gray leaf spot (GLS) caused by Cercospora zeae-maydis or Cercospora Zeina plays an urgent role in improving GLS resistance in maize breeding practice. In our study, two groups of recombinant inbred line (RIL) populations derived from CML373×Ye107 (176 RILs) and Chang7-2×Ye107 (190 RILs) were generated and subjected to genotyping-by-sequencing (GBS). GBS technology was used for large-scale single nucleotide polymorphism (SNP) discovery and simultaneous
more » ... and simultaneous genotyping of all F7 lines from two related RIL populations in order to identify quantitative trait loci (QTL) associated with GLS resistance under natural conditions of disease occurrence. A total of 1929222287 reads in CML373×Ye107 (RIL-YCML) and 2585728312 reads in Chang7-2×Ye107 (RIL-YChang), with an average of 10961490 (RIL-YCML) and 13609096 (RIL-YChang) reads per individual, were got, which was roughly equal to 0.70-fold and 0.87-fold coverage of the maize B73 RefGen_V4 genome for each F7 individual, respectively. 6418 and 5139 SNP markers were extracted to construct two high-density genetic maps. Comparative analysis using these physically mapped marker loci demonstrated a satisfactory colinear relationship with the reference genome. Eleven GLS-resistant QTL have been detected. The individual QTL accounted for 2.05-24.00% of the phenotypic variance explained (PVE). The new consensus QTL (qYCM-DS3-3/ qYCM-LT3-1/ qYCM-LT3-2) with the largest effect was located in chromosome bin 3.05, with an interval of 2.7 Mb, representing 13.08 to 24.00% of the PVE. Further gene annotation indicated that there were four candidate genes (GRMZM2G032384, GRMZM2G041415, GRMZM2G041544, and GRMZM2G035992) for qYCM-LT3-1, which may be related to GLS resistance.
doi:10.21203/rs.3.rs-179335/v1 fatcat:x24golk7t5gonmqos6kju7ct6u