Open‑pollinated (OP)
Pollinated naturally (insects, wind or self). Saved seed stays “true to type” if it hasn’t crossed with other varieties. Great for seed‑saving and diversity.
Heirloom
An OP with history and community stewardship—often brilliant flavour and stories, but more variable in size, timing and pack‑out.
F1 hybrid
The first‑generation cross between two carefully inbred parent lines, designed to combine traits (yield, firmness, disease resistance, shape/colour) and capture hybrid vigour (heterosis).
Grafted tomato
Not a seed type. A chosen fruiting variety (scion) is joined onto a vigorous, disease‑tolerant rootstock—ideal for tired or pathogen‑prone soils, salinity and heat stress.
Why F1s often out‑yield OPs & heirlooms
- Hybrid vigour: Distinct parents produce offspring that grow harder, set more fruit and handle stress better.
- Stacked resistance: Modern F1s pyramid resistances (wilts, viruses, nematodes), letting plants put energy into fruit rather than fighting disease.
- Uniformity: More consistent size, colour and maturity—easier harvest planning, freight and retail presentation.
OPs and heirlooms still shine for flavour exploration and seed‑saving—just expect more variability.
Pollination in Australia (what’s different here)
- Tomatoes self‑pollinate, but vibration improves set (greenhouse wands/automated systems).
- No bumblebees on mainland Australia: they’re restricted under biosecurity rules; report any sightings to your state DPI. Some projects use robotic or mechanical pollination instead.
- Native buzzers: research continues on Australia’s blue‑banded bees (Amegilla spp.) as effective buzz‑pollinators.
How a commercial F1 tomato is made
- Define the brief: market segment, flavour, shelf‑life, climate, disease profile.
- Build the parents: several generations of selfing and selection; some traits introgressed from wild relatives.
- Test‑cross & trial: candidate crosses run in replicated, multi‑location trials (open field & protected) for yield stability and quality.
- Disease screening: greenhouse/field hotspot tests for priority pathogens (e.g., wilts, viruses), with seed‑health labs involved.
- Hybrid seed production: tomatoes mostly self, so commercial hybrid seed is typically made by manual emasculation of the female parent and hand‑pollination—plus isolation and rouging for purity.
- Clean, test, certify: lots tested for germination, purity and seed‑borne pathogens under international rules (ISTA/ISHI).
- Timeline: first cross to a named hybrid in broad distribution often takes several seasons to a decade, depending on traits and trial windows.
Global pipeline: why the Netherlands & France matter
Australia’s light, heat and pest pressure make it a valuable trial environment. To keep breeding and seed production moving year‑round, seed houses shuttle elite lines and lots between Southern Hemisphere trials (e.g., Australia/Chile) and Northern Hemisphere hubs—especially the Netherlands and France—where dense glasshouse infrastructure, specialist labour and seed‑quality labs allow controlled crosses, grow‑outs and rigorous QC. Fresh batches are then shipped worldwide.
At‑a‑glance: what should I plant?
| Feature | F1 Hybrid | Open‑pollinated (OP) | Heirloom (OP) | Grafted plant* |
|---|---|---|---|---|
| Ideal for | High yields, uniform harvests, market/retail | Seed‑saving, on‑farm selection | Flavour, diversity, story | Sites with soil‑borne disease, salinity or heat stress |
| Expected yield | Higher (hybrid vigour) | Moderate, variable | Moderate, variable | Often higher vs same scion ungrafted |
| Uniformity | High | Moderate | Lower | Follows the scion variety |
| Disease resistance | Pyramided packages common | Line‑specific; often fewer stacked genes | Line‑specific; often fewer stacked genes | Rootstock adds soil‑borne tolerance |
| Seed saving | Not recommended (F2 segregates) | Yes (true‑to‑type if isolated) | Yes (true‑to‑type if isolated) | Not applicable (clonal union) |
| Up‑front cost | Higher per seed | Lower per seed | Lower per seed | Higher plant price (grafting labour) |
| Notes | Great for pack‑out and planning | Good for local adaptation over time | Expect variability; amazing flavours | *Scion chooses fruit type; rootstock drives resilience |
Further reading (neutral & practical)
- UC ANR — Heirloom, OP or hybrid?
- Peer‑reviewed reviews on tomato hybrid seed production and breeding strategies.
- Vegetable grafting overviews: SARE and Frontiers.
- Seed testing rules used by labs: ISTA International Rules for Seed Testing.
- Biosecurity (Australia): check your state DPI and Plant Health Australia for ToBRFV updates and movement conditions.
