Abstract
BackgroundKernel weight and size are important components of grain yield in cereals. Although some information is available concerning the map positions of quantitative trait loci (QTL) for kernel weight and size in maize, little is known about the molecular mechanisms of these QTLs. qGW4.05 is a major QTL that is associated with kernel weight and size in maize. We combined linkage analysis and association mapping to fine-map and identify candidate gene(s) at qGW4.05.ResultsQTL qGW4.05 was fine-mapped to a 279.6-kb interval in a segregating population derived from a cross of Huangzaosi with LV28. By combining the results of regional association mapping and linkage analysis, we identified GRMZM2G039934 as a candidate gene responsible for qGW4.05. Candidate gene-based association mapping was conducted using a panel of 184 inbred lines with variable kernel weights and kernel sizes. Six polymorphic sites in the gene GRMZM2G039934 were significantly associated with kernel weight and kernel size.ConclusionThe results of linkage analysis and association mapping revealed that GRMZM2G039934 is the most likely candidate gene for qGW4.05. These results will improve our understanding of the genetic architecture and molecular mechanisms underlying kernel development in maize.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0768-6) contains supplementary material, which is available to authorized users.
Highlights
Kernel weight and size are important components of grain yield in cereals
To confirm the quantitative trait loci (QTL) on bin 4.05, we developed 20 new polymorphic markers (Additional file 1: Table S1) between LV28 and HZS on chromosome 4 and identified the genotype of all recombinant inbred line (RIL) families from LV28 × HZS
Kernel weight and kernel width differed significantly (P < 0.01) between the RILs homozygous for HZS and LV28 in all six environments (Fig. 4, Additional file 3: Figure S1), and kernel length differed significantly (P < 0.01) in all but the Xinjiang 2010 environment (Additional file 4: Figure S2). These findings suggest that the QTL in the interval of NO4-ND4M26 can affect kernel weight and kernel size in the RIL population, which is in agreement with our previous fine-mapping results
Summary
Kernel weight and size are important components of grain yield in cereals. Maize yield is mainly composed of effective ear number, kernel number per ear and kernel weight. Understanding the genetic and molecular basis of kernel weight and kernel size is extremely important for the breeding of high-yield maize. Due to the rapid development of molecular biotechnology, comparative genomics, and bioinformatics, many genes associated with maize flowering time, plant architecture and other traits, such as vgt1 [1], ZmCCT [2, 3], spi1 [4], ZmCLA4 [5], Fea2 [6, 7] and tga1 [8], have been positionally cloned.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
