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Abstract It is well known that if a fruit is harvested extremely early its development and function are interrupted, and it may never attain full maturity and optimal quality. Reports revealing insights regarding the alterations of maturation, ripening and postharvest quality in very early picked fruits are rare. We examined the effects of early harvesting on tomatoes by characterizing different accessions at the molecular, physiological, and biochemical levels. We found that even very early–harvested fruits could achieve postharvest maturation and ripening though with some defects in pigment and cuticle formation, and seeds from very early–harvested fruits could still germinate and develop as normal and healthy plants. One critical regulator of tomato cuticle integrity, SlCER1–2, was shown to contribute to cuticle defects in very early–harvested fruits. Very early fruit harvest still allowing ripening and seed development indicate that the genetic and physiological programs of later maturation and ripening are set into motion early in fruit development and are not dependent on complete fruit expansion nor attachment to the plant.
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Evidence for human‐caused founder effect in populations of Solanum jamesii found at archaeological sites: I. Breeding experiments and the geography of sexual reproduction
Abstract Premise: Plant domestication can be detected when transport, use, and manipulation of propagules impact reproductive functionality, especially in species with selfincompatible breeding systems. Methods: Evidence for human‐caused founder effect in the Four Corners potato (Solanum jamesii Torr.) was examined by conducting 526 controlled matings between archaeological and non‐archaeological populations from field‐collected tubers grown in a greenhouse. Specimens from 24 major herbaria and collection records from >160 populations were examined to determine which produced fruits. Results: Archaeological populations did not produce any fruits when self‐crossed or outcrossed between individuals from the same source. A weak ability to self‐ or outcross within populations was observed in non‐archaeological populations. Outcrossing between archaeological and non‐archaeological populations, however, produced fully formed, seed‐containing fruits, especially with a non‐archaeological pollen source. Fruit formation was observed in 51 of 162 occurrences, with minimal evidence of constraint by monsoonal drought, lack of pollinators, or spatial separation of suitable partners. Some archaeological populations (especially those along ancient trade routes) had records of fruit production (Chaco Canyon), while others (those in northern Arizona, western Colorado, and southern Utah) did not. Conclusions: The present study suggests that archaeological populations could have different origins at different times—some descending directly from large gene pools to the south and others derived from gardens already established around occupations. The latter experienced a chain of founder events, which presumably would further reduce genetic diversity and mating capability. Consequently, some archaeological populations lack the genetic ability to sexually reproduce, likely as the result of human‐caused founder effect.
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- Award ID(s):
- 1827414
- PAR ID:
- 10298378
- Editor(s):
- Diggle, Pam
- Date Published:
- Journal Name:
- American Journal of Botany
- Volume:
- 108
- Issue:
- 9
- ISSN:
- 0002-9122
- Page Range / eLocation ID:
- 1808-1815
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/ajb2.1737
