Our Adventure With Victoria 2003
Will The Real V. cruziana Please Stand Up
Having reached the end of our sixth season of serious Victoria breeding and seed production, we are seeing some trends in germination and viability that are quite interesting and, in several cases, rather alarming.
First let us say that what is below doesn't apply to any of the hybrids, primary ('Adventure' and 'Longwood Hybrid') or back-cross ('Atlantis', 'Columbia', 'Discovery' and 'Challenger'). They continue to germinate at about the same rates as always, though 'Columbia' has improved in the last two years. We also see that certain parent combinations produce varying degrees of seed and seedling viability and try not to distribute poor lots to anyone else.
One of our long term goals has been straight line breeding of the species, selfing certain plants from various locations year after year in order to insure genetic diversity in cultivated plants for the future. From time to time we cross these species plants to get a certain amount of "hybrid vigor" even within the species.
Try as we might, over time these straight lines are dying out. Sometimes even first year straight line seeds have a fairly low germination rate compared with crosses and produce weaker seedlings. If we can get plants going at all, several of these lines have died off without producing many, if any, seeds.
This actually makes sense. In the wild, seeds from crosses would naturally be more vigorous than selfs but, having more control of cultivated plants, we thought that we could influence the outcome. In fact, it didn't occur to us that we couldn't until it was/is almost too late to do anything about it. In the short term we can pay more attention to keeping crossed lines separated as long as we can and there is some evidence that even the crossing of siblings may give the desired result of more vigor.
In building the Victoria Pedigrees now on the web site, it was as sad to see lines die out on paper as it is to see it happen here. These observations may help explain why botanical gardens, sometimes only able to grow one species plant, have greater and greater difficulty keeping their Victorias going. It may also shed light on why some gardens have difficulty producing hybrid seeds, even with both species blooming at the same time. They have become weaker, even relative to breeding.
Because we wanted to be sure of having species plants in synch to make the hybrids (cruziana tend to be earlier to flower than amazonica), we have always grown multiple plants of each species. We are only now realizing the benefit of making cruziana crosses while we've waited for amazonica to flower and amazonica crosses after the cruzianas have finished. They make the strongest plants.
This is especially true with amazonica. Seeds collected in the wild in 1998 and 1999 proved to germinate reasonably well in the first few months after collection and then viability dropped dramatically. This has also proven true of most of our straight lines in the first generation. Their second generation is where we really begin to see the weakness. Some lines have been weak in the first generation.
Cruziana is a different story. In recent years, cultivated cruziana has sprouted easily the first year and been far easier to grow than amazonica. This is NOT the case with the seeds collected in Paraguay in 2001 (the only wild collected cruziana seeds in 100 years - see Seeds of the Century). Their germination rate was less than .001% the first year, only slightly higher the second year, with considerably higher rates this year, the third after collection.
George Pring wrote of V. cruziana, in the Missouri Botanical Garden Bulletin, Vol. 37, 1949, "It is essential that the seeds be fully ripe before being planted, those two years old showing a better percentage of germination than young seeds. Seeds have been known to germinate in the pool outside (despite it being drained in the winter) three years after the plant had been grown there."
We were able to grow and collect seeds from a Paraguayan cruziana in 2001. Almost none have sprouted. We were able to grow and collect seeds from a different Paraguayan in 2002. Almost none have sprouted. Those few that did sprout didn't survive. In 2003 we grew three Paraguayans, collecting selfs from the oldest (none have sprouted even though collected early in the season) and crosses once the second and third began to bloom (one has sprouted). Most lots of domestic cruzianas have sprouted spontaneously to the point we've had to chill them to prevent it.
Granted this is a small sample from which to draw conclusions about the purity of the domestic cruzianas, so we are not doing so. We hope to build additional data and observations about wild cruziana if we are successful with seeds collected in Argentina in 2002 by Jorge Monteverde and Walter Pagels. The only real answer is DNA testing, something we are pursuing in conjunction with Joe Summers.
Returning to germination, line-bred species seeds may show approximately equal germination with crossed species when looking at sheer sprout numbers, but observation of seedlings' size and strength bears out the weakness of the line-breds over time. It can be seen in careful perusal of the data, following development rates and survival. Until now we, like everyone else, have thought germination and strong growth of the species (even with "nicking") was just good luck or bad, successful culture or poor, but we now can see a pattern emerging in the genes.
Proper storage still matters. All the cultural measures must still be taken. But starting with strong seeds makes the cultivation process far easier.