Linkage map construction and QTL analysis for Betula platyphylla Suk using RAPD, AFLP, ISSR and SSR

AbstractA linkage map for Betula platyphylla Suk was constructed based on RAPD, ISSR, AFLP and SSR markers by a pseudo-testcross mapping strategy. A F1segregating population including 80 progenies was obtained from the cross between two superior trees selected from Qinghai and Wangqing provenance, respectively. The paternal map was constructed with 282 markers consisting of 14 major and 15 minor (5 triplets and 10 doublets) linkage groups and spanning 1131 cM at an average distance of 4.0 cM between adjacent markers. The maternal map has 277 markers consisting of 15 major and 8 minor (5 triplets and 3 doublets) groups covering 1288 cM at an average distance of 4.6 cM between adjacent markers. In the same pedigree we investigated association of genetic markers with seedling stem height and circumference. The composite interval mapping was used to detect the number of quantitative trait loci and their position on the genetic linkage maps. Three QTLs (one on the male map and two on the female map) were found explaining 13.4%, 17.5% and 18.8% of the trait variation, respectively.

Download Full-text

Genetic linkage map of Betula pendula Roth and Betula platyphylla Suk based on random amplified polymorphisms DNA markers

Hereditas (Beijing) ◽

10.1360/yc-007-0867 ◽

2007 ◽

Vol 29 (07) ◽

pp. 867 ◽

Cited By ~ 4

Author(s):

Ting-Bo JIANG

Keyword(s):

Linkage Map ◽

Dna Markers ◽

Genetic Linkage ◽

Betula Pendula ◽

Genetic Linkage Map ◽

Betula Platyphylla ◽

Betula Pendula Roth ◽

Betula Platyphylla Suk

Download Full-text

Molecular mapping of QTLs for resistance to Gibberella ear rot, in corn, caused by Fusarium graminearum

Genome ◽

10.1139/g05-014 ◽

2005 ◽

Vol 48 (3) ◽

pp. 521-533 ◽

Cited By ~ 53

Author(s):

M Liakat Ali ◽

Jeff H Taylor ◽

Liu Jie ◽

Genlou Sun ◽

Manilal William ◽

...

Keyword(s):

Linkage Group ◽

Linkage Map ◽

Fusarium Graminearum ◽

Molecular Mapping ◽

Average Distance ◽

Interval Mapping ◽

Ear Rot ◽

Resistant Parent ◽

Gibberella Ear Rot ◽

Group 5

Gibberella ear rot, caused by the fungus Fusarium graminearum Schwabe, is a serious disease of corn (Zea mays) grown in northern climates. Infected corn is lower yielding and contains toxins that are dangerous to livestock and humans. Resistance to ear rot in corn is quantitative, specific to the mode of fungal entry (silk channels or kernel wounds), and highly influenced by the environment. Evaluations of ear rot resistance are complex and subjective; and they need to be repeated over several years. All of these factors have hampered attempts to develop F. graminearum resistant corn varieties. The aim of this study was to identify molecular markers linked to the genes for resistance to Gibberella ear rot. A recombinant inbred (RI) population, produced from a cross between a Gibberella ear rot resistant line (CO387) and a susceptible line (CG62), was field-inoculated and scored for Gibberella ear rot symptoms in the F4, F6, and F7 generations. The distributions of disease scores were continuous, indicating that resistance is probably conditioned by multiple loci. A molecular linkage map, based on segregation in the F5 RI population, contained 162 markers distributed over 10 linkage groups and had a total length of 2237 cM with an average distance between markers of 13.8 cM. Composite interval mapping identified 11 quantitative trait loci (QTLs) for Gibberella ear rot resistance following silk inoculation and 18 QTLs following kernel inoculation in 4 environments that accounted for 6.7%–35% of the total phenotypic variation. Only 2 QTLs (on linkage group 7) were detected in more than 1 test for silk resistance, and only 1 QTL (on linkage group 5) was detected in more than 1 test for kernel resistance, confirming the strong influence of the environment on these traits. The majority of the favorable alleles were derived from the resistant parent (CO387). The germplasm and markers for QTLs with significant phenotypic effects may be useful for marker-assisted selection to incorporate Gibberella ear rot resistance into commercial corn cultivars.Key words: Gibberella ear rot, corn, Fusarium graminearum, QTL, linkage map.

Download Full-text