Red nectar presentation and characterization of the breeding system of an Andean nightshade

Abstract

Flowers of Jaltomata weigendiana (Solanaceae) secrete red nectar that is visible through the partially translucent corolla. We report the pattern of nectar presentation during the sexual phases of the flower and characterize the breeding system. Comparison of flower sets experiencing daily removal starting Day 1 with flowers that accumulated nectar for one or two days prior to daily removal revealed no discernible effect on the life-of-the-flower nectar production, sugar production and floral longevity. Flowers produce about the same cumulative volume of nectar during the two sexual phases. However, cumulative nectar sugar production is about 4 times higher during the male phase. Nectar standing crop ranged from 4–26.6 µl for Day 1 flowers and 0–8.7 µl for flowers from which nectar was removed the previous day. With daily removal of nectar, 21 of 40 flowers contained no nectar during the last day of the flower’s life. All unmanipulated flowers developed fruits (autonomous self-pollination). However, manual self-pollinations and manual cross-pollinations resulted in fruits that weighed significantly more and had significantly more seeds than fruits produced by autonomous self-pollination. Protogyny and herkogamy promote cross-pollination, but delayed autonomous selfing at the end of the flower’s life ensures seed set if pollinator-mediated pollination fails.

Keywords:

• Autonomous self-pollination
• colored nectar. edible fruit
• Jaltomata
• Solanaceae
• floral longevity
• red nectar
• protogyny

Acknowledgements

We thank Gregory J. Anderson and David A. Spector for review prior to submission, Paul R. Wilson for growing the research plants prior to the study and suggesting the addition of the corolla expansion data, Nathaniel T. Mione for assistance, Jack Lamb for photos of hummingbirds visiting J. viridiflora, and Donald Blume for care of living plants.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

T. M. was supported by a grant from the Connecticut State University system.