Defining the Genetic Architecture Underlying Female- and Male-Mediated Nonrandom Mating and Seed Yield Traits in Arabidopsis

Abstract

Postpollination nonrandom mating among compatible mates is a widespread phenomenon in plants and is genetically undefined. In this study, we used the recombinant inbred line (RIL) population between Landsberg erecta and Columbia (Col) accessions of Arabidopsis (Arabidopsis thaliana) to define the genetic architecture underlying both female-and male-mediated nonrandom mating traits. To map the genetic loci responsible for male-mediated nonrandom mating, we performed mixed pollinations with Col and RIL pollen on Col pistils. To map the genetic loci responsible for female-mediated nonrandom mating, we performed mixed pollinations with Col and Landsberg erecta pollen on RIL pistils. With these data, we performed composite interval mapping to identify two quantitative trait loci (QTLs) that control male-mediated nonrandom mating. We detected epistatic interactions between these two loci. We also explored female-and male-mediated traits involved in seed yield in mixed pollinations. We detected three female QTLs and one male QTL involved in directing seed number per fruit. To our knowledge, the results of these experiments represent the first time the female and male components of seed yield and nonrandom mating have been separately mapped.

New Arabidopsis Advanced Intercross Recombinant Inbred Lines Reveal Female Control of Nonrandom Mating

“…More direct measures of male function, such as in vitro and in vivo pollen tube growth rates, verify variation in male function and demonstrable impact on nonrandom mating (Snow andSpira, 1991a, 1991b;Pasonen et al, 1999;Skogsmyr and Lankinen, 1999;Stephenson et al, 2001;Lankinen and Skogsmyr, 2002;Lankinen et al, 2009). Finally, recent work in our laboratory has directly mapped the genetic loci responsible for the control of male-mediated nonrandom mating in Arabidopsis (Arabidopsis thaliana; Carlson et al, 2011).…”

“…1) for malemediated nonrandom mating. Since two QTLs using this assay on a different RIL population have already been identified, we adopted the convention of numbering these QTLs consecutively (Carlson et al, 2011). Thus, the four QTLs we identify in this report are labeled qMNRM3 to qMNRM6.…”

“…Nonrandom mating at this level has received intense interest for its potential to avoid inbreeding depression and its potential to be the result of sexual selection (Charnov, 1979;Mulcahy, 1979;Willson, 1979;Queller, 1983;Stephenson and Bertin, 1983;Willson and Burley, 1983;Marshall and Ellstrand, 1986;Mulcahy and Mulcahy, 1987;Cruzan, 1990;Quesada et al, 1993;Snow, 1994;Paschke et al, 2002;Skogsmyr and Lankinen, 2002;Stephenson et al, 2003;Armbruster and Rogers, 2004;Bernasconi et al, 2004;Lankinen and Armbruster, 2007). Despite a long history of theoretical and experimental attention, very little is known about the underlying genetics that govern the process (Carlson et al, 2011).…”

“…In previous work, we developed a system in Arabidopsis to assay nonrandom mating and showed its utility for genetically mapping the loci responsible (Carlson et al, 2009(Carlson et al, , 2011. Pursuing the genetics of nonrandom mating in a largely selfing plant such as Arabidopsis provides both theoretical and practical advantages.…”

“…By phenotyping these lines, we can statistically associate nonrandom mating and seed yield phenotypes with chromosomal regions. We chose these two accessions because (1) our previous experiments predict clear female control of nonrandom mating and (2) we have previously mapped male-mediated nonrandom mating controls using a Col-4/Landsberg mapping population (a population that does not display female control of nonrandom mating; Carlson et al, 2011). Thus, this new population provides us the opportunity to map loci that control female nonrandom mating and investigate the degree of conservation of loci that affect malemediated nonrandom mating.…”