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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #398853
Research Project: Database Tools for Managing and Analyzing Big Data Sets to Enhance Small Grains Breeding

Location: Plant, Soil and Nutrition Research

Title: Sexual dimorphism and the effect of wild introgressions on recombination in cassava (Manihot esculenta Crantz) breeding germplasm

Author
item CHAN, ARIEL - Cornell University
item VILLWOCK, SEREN - Cornell University
item WILLIAMS, AMY - Cornell University
item Jannink, Jean-Luc

Submitted to: Genes, Genomes, Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2021
Publication Date: 11/15/2021
Citation: Chan, A.W., Villwock, S.S., Williams, A.L., Jannink, J. 2021. Sexual dimorphism and the effect of wild introgressions on recombination in cassava (Manihot esculenta Crantz) breeding germplasm. Genes, Genomes, Genetics. 12(1): Article jkab372. https://doi.org/10.1093/g3journal/jkab372.
DOI: https://doi.org/10.1093/g3journal/jkab372

Interpretive Summary: Recombination has essential functions in meiosis, evolution, and breeding. The frequency and distribution of recombination can vary across species and between sexes. Here, we examine recombination across the 18 chromosomes of cassava (Manihot esculenta Crantz) with respect to male and female meioses and known introgressions from the wild relative Manihot glaziovii. We infer crossovers from DNA marker data and a validated multigenerational pedigree from the International Institute of Tropical Agriculture cassava breeding program. We used this information to construct new genetic maps and compared them to an existing map. We observed higher recombination rates in females compared to males, and lower recombination rates in M. glaziovii introgression segments on chromosomes 1 and 4, with suppressed recombination along the entire length of the chromosome in the case of the chromosome 4 introgression.

Technical Abstract: Recombination has essential functions in meiosis, evolution, and breeding. The frequency and distribution of crossovers dictate the generation of new allele combinations and can vary across species and between sexes. Here, we examine recombination landscapes across the 18 chromosomes of cassava (Manihot esculenta Crantz) with respect to male and female meioses and known introgressions from the wild relative Manihot glaziovii. We used SHAPEIT2 and duoHMM to infer crossovers from genotyping-by-sequencing data and a validated multigenerational pedigree from the International Institute of Tropical Agriculture cassava breeding germplasm consisting of 7020 informative meioses. We then constructed new genetic maps and compared them to an existing map previously constructed by the International Cassava Genetic Map Consortium. We observed higher recombination rates in females compared to males, and lower recombination rates in M. glaziovii introgression segments on chromosomes 1 and 4, with suppressed recombination along the entire length of the chromosome in the case of the chromosome 4 introgression. Finally, we discuss hypothesized mechanisms underlying our observations of heterochiasmy and crossover suppression and discuss the broader implications for plant breeding.