Having understanding intraspecific type away from recombination rates during the maize, we authored a few 1 / dos of-sib boards, one to getting Damage and one for Flint inbred lines. Drop and Flint are a couple of maize gene pools that will be extremely important to possess hybrid breeding within the European countries . Both half-sib boards composed a total of twenty four full-sib household. The newest Drop committee constitutes ten crosses from a main Dent inbred range (F353) with diverse Damage inventor inbreds of your Eu Damage gene pool that were developed in European countries and you may North america. On the Flint committee a central Flint inbred line (UH007) is crossed so you’re able to eleven genetically varied Flint creator inbreds of Western european Flint breeding issue. The fresh new Flint founder contours come from early maize introductions to help you The country randki clover of spain and away from thus-titled North Flints of France and you may Germany. Concurrently, a couple of mutual crosses among them central Drop and you will Flint lines had been analyzed as well as in for each panel you to definitely get across with the All of us Dent line B73 is actually included as a link with the us nested association mapping (NAM) inhabitants .

Here, we report on the analysis of the variation of recombination rate in 23 populations of maize using SNPs from the MaizeSNP50 BeadChip . All populations consist of doubled haploid (DH) lines obtained by in vivo haploid induction . DH lines produced with this method reflect female meiosis. Unlike F₂ or RILs, DH lines have the great advantage that the genetic information of each gamete is directly observed. Our objectives were to analyze intraspecific variation for (1) GWRR and chromosome-wide recombination rate, (2) recombination landscape along chromosomes, and (3) CO interference, using high-density genetic linkage maps. We found significant differences of GWRR between individual populations as well as between Dent ? Dent versus Flint ? Flint populations, but not between the Dent and Flint gene pools in general. GWRR was not correlated with the genetic structure of the lines as inferred from admixture analysis. We analyzed the recombination landscapes in all populations and found significant differences between individual populations and between pools. Finally, we characterized quantitatively the interfering and non-interfering CO formation pathways and found a negative correlation over all chromosomes between interference intensity of pathway P1 and GWRR.

Efficiency

We constructed two half-sib panels comprising a total of 24 maize full-sib families of DH lines for the analysis of intraspecific variation of recombination rates. The full-sib families within the two panels represent the diversity of important founder lines of the European Dent and Flint germplasm, respectively (Table 1; Additional file 1). In the Dent panel (prefix CFD), all full-sib families have the same common parental line F353 which was crossed to diverse Dent founder lines. The common parent of the Flint full-sib families (prefix CFF) is line UH007, which was crossed to diverse Flint founder lines. ₁ plants for in vivo haploid induction, so our maps reflect only female meioses. Details on the diversity analysis of the parental lines are given in Additional file 2.

Throughout crosses, brand new haploid inducer line was applied due to the fact male father or mother whenever crossed on the F

Since the a primary help the study away from recombination, individual hereditary charts were developed to possess 23 out from the twenty-four populations and each of the ten chromosomes. Chart statistics are provided in Desk step one with an increase of information within the Extra file step three, additionally the done set of marker ranking in most charts which have this new brutal segregation data is given from inside the More file 4. Overall, 39,439 SNPs of your MaizeSNP50 assortment might possibly be mapped when you look at the at the least that populace. Over all communities, doing 33,884 COs were seen in 2,233 ladies meioses and, typically, 11,988 SNPs have been mapped in one given people. The typical having Damage ? Drop populations (every CFD except CFD01) is thirteen,247 markers mapped as well as Flint ? Flint communities (all the CFF but CFF01 and you will CFF02) the average try 9,874. To have society CFF05, which manufactured merely 34 DHs, no secure map was gotten. The full amount of hereditary charts varied from 1,180 centiMorgan (cM) from inside the populace CFD05 to 1,893 cM inside CFF03 that have a mean of 1,508 ± 185 cM (indicate ± practical deviation). The typical genetic chart length regarding ten Dent ? Dent communities (CFD02 so you can CFD12) was step one,353 ± 99 cM, since the 11 genetic maps of Flint ? Flint communities (CFF03 so you can CFF15) had been, an average of, expanded on step 1,645 ± 154 cM. The three maps out-of crosses anywhere between Dent and you can Flint mothers (CFD01, CFF01, CFF02) got an advanced average amount of step 1,570 ± 85 cM. The greatest pit from inside the a hereditary chart try 53.eight cM towards long-arm away from chromosome seven (7L) into the population CFF13, in which no SNPs were polymorphic within mothers, most likely because of label-by-origin (IBD). Details about genome-large range and IBD markets between moms and dads of one’s mapping populations come in Even more file 2. Synteny and you will colinearity of your genetic maps is actually compared to the fresh new B73 AGPv2 genome set up. Typically, a premier agreement is discovered, demonstrating the latest highest texture from marker order across populations, having couple exceptions due to the fact revealed inside More document 2.