Abstract Detail

Reproductive Processes

De Lima Berg , Karla [1], Schwoch, Jaime [1], Cruzan, Mitchell [1].

Gametophytic selection and selective embryo abortion in Mimulus guttatus.

The haplodiplontic life cycle of plants presents unique opportunities for selection at multiple life stages. When selection occurs within individuals during somatic growth and reproduction it is referred to as developmental selection. Developmental selection can occur during pollen tube elongation (gametophytic selection, or GS) and selective abortion of embryos (SEA) and can affect plant fitness within a single generation. However, the prevalence and strength of GS and SEA is not well understood. We estimated the proportion of transcribed loci affected by GS or SEA through analyses of segregation distortion in Mimulus guttatus. Leaf tissue was collected from 47 seedlings produced by an autogamous cross, and mRNA sequenced to identify SNPs within transcribed regions. We developed mathematical models to calculate expected segregation ratios for GS and SEA; observed values were then compared with these models via chi-square tests and the strength of selection at each locus was quantified. Out of 4,424 loci exhibiting segregation distortion, 31% fit the GS and SEA models (p ≤ 0.05). Selection coefficients among these loci ranged from 0.2 to 1, with the latter occurring most frequently. Evidence of positive selection due to GS and SEA was found for a smaller number of gene regions. These results suggest that selection during development is strong and has the potential to accelerate the purging of genetic load in plant populations.

1 - Portland State University, Department Of Biology, 1825 SW Broadway1719 SW 10th Ave, SRTC Rm 246 - Biology, Portland, OR, 97201, USA

developmental selection
gametophytic selection
selective embryo abortion
segregation distortion.

Presentation Type: Oral Paper
Session: REP3, Reproductive Processes 3
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 10:30 AM
Number: REP3003
Abstract ID:730
Candidate for Awards:None

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