From
a few years I am growing 2 rare half-hardy tamarillo species: Hardy
Tamarillo Cyphomandra
corymbiflora
and Guava
Tamarillo C.
fragrans = C. diploconos.
I have already described the in 2 other posts in February and
September 2018 yr. Last year I tried to cross both species to obtain
a hybrid which has been described by prof. Lynn Bohs as easy to
creating and fully fertile [Crossing Studies in Cyphomandra
(Solanaceae)
and Their Systematic and Evolutionary Significancs. American Journal
of Botany,Vol. 78, No. 12 (Dec., 1991)].
 |
| Cyphomandra corymbiflora x fragrans (F1) - young seedling |
Bellow
I am going to describe my experiences with crossing (hand pollinating
the flowers etc.) these 2 species and sowing their hybrid seeds (with
photos). I can say that both species are self-incompatible and the
flowers are naturally pollinated by bumblebees (at least in Europe),
but with very small success in my experience (maybe due to small
amount of these insects in my area). I ready that crossing
female C.
corymbiflora
and male C.
fragrans
gives
fertile seeds (and next healthy viable hybrids) but adverse
combination (female C.
fragrans and
male C.
cormbiflora)
is not succeed.
Hand
pollinating:
I made a mistake and I first started to pollinating already opened
flowers (which could be pollinated by bees before) but after first
pollination I covered whole inflorescence in organza bag, so next
fruits (which I pollinated later) was certain hybrid. Probability
that any of these hand pollinated (crossing) fruits is not hybrid, is
very low. I had very large success with hybrid hand pollination,
because almost all (I estimate it for about 60-70%) pollinated
flowers (C.
corymbiflora x
C. fragrans)
developed info fruits (finally I harvested over 20 hybrid fruits). In
comparison I harvested only a few (about 5) fruits from flowers
pollinated by bumblebees (from 3 trees of
C. corymbiflora)
after whole long flowering season in 2018 yr. The hand pollinating
was made in August (C.
cormbiflora
flowered from May/June, but C.
fragrans
created first flowers as late as in early August, so crossing was
possible only in this time). I had much more success with hybrid
pollination than pollination of C.
corymbiflora by
pollen of other C.
corymbiflora
(because it is very difficult to get pollen from flowers of C.
corymbiflora,
because it creates very little amount of it in its anthers, but the
C.
fragrans has
flowers fully of pollen, so its preparing from them is much easier).
I will show how I made pollination on the photos bellow. The fruits
ripened about 4 months later, in November and December. In this time
plants were stored (since September) in cool cellar in about 5-10C =
41-50F degree first (and next, in end of this period, even only about
2C = 35F degree). So fruits had not very good temperature to ripe
well and they fall down half-ripe. Next I stored them in paper bag
with ripe apples (which are emitting an ethylene) to they become
overripe (within 2-3 weeks after dropping the fruits and harvest). I
harvested numerous hybrid seeds but they were worse developed
(something smaller) than clean C.
corymbiflora and
their germination rate was low (about 5%, maybe more). The seedlings
are small yet, but they are growing healthy. I will make next
update-post when they grow up. I am very curious of appearance of
this hybrid. It is said to have intermediate features between its
parents. Now there is visible that young seedlings have hairy leaves
(similar as female parent – C.
corymbiflora).
 |
| Cyphomandra fragrans - flowers (young ones are purple, older ones are yellowish) |
 |
| Harvesting a pollen to hand pollination - 1 step |
 |
| Harvesting a pollen to hand pollination - 2 step (removing anthers) |
 |
| Harvesting a pollen to hand pollination - 3 step |
 |
| Taking a pollen to brush |
 |
| Hand pollination of flowers Cyphomandra corymbiflora by pollen of C. fragrans |
 |
| Young fruits a few days after the pollination |
 |
| Older fruits |
 |
| A success of hand pollination was high |
 |
| ... in comparison to pollinating to bee pollinating (which was low succeed) |
 |
| Fruits obtained after crossing pollination Cyphomandra corymbiflora x C. fragrans - just ofter harvesting (still green) |
 |
| The fruits after overripening |
 |
| There are visible well developed seeds (paler?) as well as degenerated ones (darker) |
 |
| Overripe fruits (the fruits after crossing) were distinctly yellowish |
 |
| The fruits of clean Cyphomandra corymbiflora after overripening (still clean green outside, not yellowish) |
 |
The seeds removed from fruits obtained after crossing pollination Cyphomandra corymbiflora x C. fragrans (viable -paler as well as degenerated -darker)
|
 |
| The young seedlings of hybrid of hardy tamarillo's Cyphomandra corymbiflora x fragrans (F1) |
I
harvested also a few fruits from C.
fragrans tree.
They were oppen pollinated (I am not sure if hybrid or apomictic –
because it is self-incompatible species and I have only 1 tree). The
fruits were green when they fall down on January 2019, and they have
not became yellow after overrripening (as fruits which I obtained
from Brazil a few years ago, which were clean yellow). The thick of
fruits was very thick, strong and flesh was acid, but almost without
aroma (cool cellar is not the best to ripening the fruits, I think).
Inside were several dozen of seeds, but almost all were probably
unviable (they have not fall down in water), only 5 seeds were
probably viable. I am going to sow them.
 |
| Cyphomandra corymbiflora and C. fragrans (comparison) - fruits just after falling |
 |
| Cyphomandra fragrans - fruits overripening |
 |
| Cyphomandra fragrans - fruits overripe |
 |
| It has very strong, thick skin |
 |
| Cyphomandra fragrans - unviable seeds |
 |
| Cyphomandra fragrans - 5 viable seeds |
