Relative success of self and outcross pollen comparing mixed- and single-donor pollinations in <i>Aquilegia caerulea</i>

Abstract

Flowers frequently receive both self (S) and outcross (OC) pollen, but S pollen often sires proportionally fewer seeds. Failure of S pollen can reflect evolved mechanisms that promote outcrossing and/or inbreeding depression expressed during seed development. The relative importance of these two processes was investigated in Aquilegia caerulea, a self-compatible perennial herb. In the field I performed single-donor (S or OC) and mixed-donor (S plus OC) pollinations to compare the relative success of both pollen types at various stages from pollen germination to seed maturity. Single-donor S pollinations produced significantly fewer and lighter seeds (x decrease = 12% and 3%, respectively) than OC pollinations. Abortion rates differed by an average of 38% whereas fertilization rates differed by only 5%, indicating that most differences in seed number arose postzygotically. This suggests that inbreeding depression was responsible for most failure of S pollen. One prezygotic effect measured was that 10% fewer S than OC pollen tubes reached ovaries after 42 hr, suggesting S pollen might fertilize proportionately fewer ovules after mixed pollination. Using allozyme markers, I found mixed-donor pollinations produced significantly more and heavier outcrossed than selfed seeds. However, the proportion of selfed seed, fertilized ovules, and aborted seeds for mixed-donor fruits were each predictable from pollen performance in single-donor fruits, suggesting that differential paternity is best explained by inbreeding depression during seed development. Even given these similarities between mixed- and single-donor fruits in the relative performance of S and OC pollen, both individual seed weight and seed set were significantly higher in multiply-sired fruits.

Local Knowledge Graph (6 entities)

Knowledge graph centered on Relative success of self and outcross pollen compa with 7 nodes and 7 connections. Top connected: Sources of variation in plant reproductive success, Pollen-pollen and pollen-style interactions during, Pollen tube attrition in Erythronium grandiflorum, Hawkmoths and the geographic patterns of floral va, The pollination ecology of Aquilegia elegantula an.

Related Works

Items connected by shared entities, co-authorship, citations, or semantic similarity.

Cited By (81 times, 1 in Knowledge Hub)

References (53)

7 in Knowledge Hub, 46 external