Abstract Detail

Population Genetics/Genomics

Cisternas, Anita [1], Fant, Jeremie [2].

Influence of flower size, herkogamy and breeding system on inbreeding and inbreeding depression of Oenothera primiveris.

Self-incompatibility can influence the levels of outcrossing in a population. Under natural conditions, it would be expected that self-incompatible populations will have less historic inbreeding than self-compatible populations. Hence when exposed to increased inbreeding rates, they would express greater inbreeding depression compare to self-compatible populations. Oenothera primiveris (Onagraceae) is an annual desert species that can be found in the three North American deserts. This species has been shown to vary in their breeding system and flower size throughout their distribution. This variation could be related to the reliability of their main pollinator, hawkmoths, across its geographic distribution.
In this work, we used Next-generation sequencing to measure Wright’s inbreeding coefficient (Fis) and population differentiation for six populations of O. primiveris. We also performed control crosses including self-pollination, biparental inbreeding and outcrossing to estimate inbreeding depression (seed viability, germination, and early survival). Flower size was measured for the different populations, specifically herkogamy since this can influence the amount of self-pollination happening in the absence of pollinators which could be related to the level of inbreeding in the populations. Hence autogamous pollination was also evaluated to estimate a potential correlation between herkogamy and seed set through autogamous pollination.
Genetic results indicate historic levels of inbreeding is related to the flower size in O.primiveris. Populations with large flower have lower inbreeding (Fis between 0.1 to 0.2) than populations with small flower size (Fis between 0.59 to 0.66). Population differentiation also indicates differentiation between these two distinct morphs. Preliminary results indicate a strong negative correlation between herkogamy and number of seeds produce through autogamy (r=-0.8). The crosses also indicate that one of the populations collected is self-incompatible while all the other populations are self-compatible. This indicates that O. primiveris can be categorized into three main groups: self-incompatible with large flowers, self-compatible with large flowers and self-compatible with small flowers. Based on these preliminary results it would be expected that inbreeding depression will be higher in the self-incompatible population than in any of the self-compatible populations.

1 - Northwestern University, Plant Biology and Conservation, 2205 Tech Drive, Evanston, IL, 60208.
2 - Chicago Botanic Gardens, Plant Biology And Conservation , 1000 Lake Cook Rd, Glencoe, IL, 60022, United States

Keywords:
none specified

Presentation Type: Oral Paper
Session: POPGEN1, Population Genetics/Genomics I
Location: Tucson H/Starr Pass
Date: Monday, July 29th, 2019
Time: 8:00 AM
Number: POPGEN1001
Abstract ID:221
Candidate for Awards:Margaret Menzel Award