Monday, March 30, 2020

News from Amasya

By Sylvain Ruaud

Between the cities of Batumi - in Georgia - in the east, and Sinope in the west, along the Black Sea, stands a coastal strip where the Cappadocia plateau slopes towards the sea. This is now Turkey, but in antiquity, it was a region colonized by the Greeks who founded there several prosperous cities, either by the sea, like the current Trabzon (Trebizonde, in the old days), Sinop ( Sinope for the Greeks), or, above all, Samsun (Amisos), either higher in the foothills of Cappadocia, and Amasya (Amaseia in ancient Greek). Amasya is located in the deep valley of the Yesilirmak river, which wiggles in the region before joining the Black Sea. In antiquity this river was called Iris! Here is a name well predestined for a river which crosses the region where our current tetraploid irises originate.

'Mrs. George Darwin'
'Mrs. Horace Darwin'
Although the city of Amasya was destined to find a prominent place in the small world of irises, it was not until the end of the 19th century and the work of Sir Michael Foster, physiologist and professor at Cambridge, and famous collector of irises that the area became important. He had started iris growing by taking an interest in the oncoclyclus irises, then also in the iris spurias with which he launched into interspecific hybridizations. He also undertook the hybridization of what was then called the Germanica irises and obtained two varieties which remained famous: 'Mrs. George Darwin 'and' Mrs. Horace Darwin 'whom he named as a token of friendship with two of his neighbors. About these varieties we read this in The World of Irises: “They were whites and the first had a touch of gold in the throat that made it stand out from any other. It also had the virtue of being very late and was at its best when most of the other varieties had finished blooming. But fine as these varieties were, Foster agreed with those who said that further improvement of the bearded irises was impossible, or at least improbable, unless new species with new characteristics could be found to use as parents”.

'Lord of June'
But where to find these new species? Foster had heard of iris with huge flowers (for the time) that were found in Asia Minor. He therefore got in touch with missionaries who then went to these regions not only for religious reasons, but also scientific purposes. It was frequently that people of church took advantage of their mission to locate plants, and many of the plants which are today frequent in our gardens come from specimens brought back by missionaries. Michael Foster's emissaries sent him irises, good, mediocre, and uninteresting; but among the good ones there were some who revolutionized the world of bearded irises. Especially a species discovered in the north of Anatolia, in the region of Amasya and baptized for this reason 'Amas'. In fact there were in Great Britain several arrivals of these exceptional irises but none has been precisely described and distributed so that it is not known exactly which is at the origin of what. The varieties that we attribute to the iris 'Amas' may come from another plant, which by the way was perhaps of the same species! The fact remains that the fame of these Anatolian irises returned to 'Amas' and, as a result, to the city of Amasya.

'Amas'
Foster made many seedlings from his 'cluster', but it was not until his death in 1907 that these were brought to the market, among with other hybrids of the same origin obtained by Foster's friend George Yeld. These new plants include 'Caterina', 'Crusader' or 'Kashmir White', from the production of Foster and 'Halo' or 'Neptune' from that of Yeld. All these novelties were not masterpieces and they turned out to be fragile, often affected by rot and not very rustic. In addition, almost all of these varieties were blue-lavender or purple. They were nevertheless successful because of their exceptional dimensions and the hopes placed in them for a renewal of bearded irises.
'Kashmir White'
It took persistence and patience to believe in this revival because it did not appear overnight! The hybridizers tore their hair out when they noticed that the crosses made between these Amasya irises and European irises did not give much: almost no seeds or plants, large, certainly, but sterile and without other qualities remarkable. It was only in the long run, after many unsuccessful attempts, that they obtained hybrids that were both fertile and beautiful. No one knew why. A botanist by the name of Strassburger had observed in 1882 the presence of chromosomes in plants, but this discovery had not aroused any interest. It was only around forty years later that the first chromosome counts revealed the reason why the Anatolian irises, and their rare fertile hybrids, were larger and more beautiful: they had four pairs of chromosomes at the place of the two pairs which characterized the ancient irises.

To fully explain this phenomenon, I have found nothing more perfect than a text written by Ben Hager, the well-known hybridizer, published in the first part of a book of artistic photographs of iris, "L'Iris” from Dutchman Josh Westrich. Here is this explanation:
All living organisms, plants and animals, are made up of cells. All cells have a common basic structure and each has a nucleus. In only one of its infinitesimal entities are numerous chromosomes grouped together, the number of which varies according to organisms. Chromosomes carry a genetic map that controls the development and characters of the new organism after fertilization. The egg cell produces new cells that are identical in every way and intended to form a completely rejuvenated structure. At the moment when the reproductive cells or gametes are formed in the flower, the number of chromosomes is divided into two equal batches but with, often, a mixing of the characters carried by the chromosomes. Male and female cells from the same parent (self-fertilization) or from different parents, will give egg cells with a different genetic heritage and will produce different plants. (...) "

Nature prefers simplicity. Individuals resulting from the fusion of two reduced batches of chromosomes are called diploids. But accidents happen: if, during the formation of gametes, the cells do not correctly reduce the number of chromosomes, the egg contains four sets of chromosomes instead of two. Such cells are called tetraploids; because of the accident to which they are due, they have everything in duplicate. "

Why did the first crosses between the irises of Amasya and the “old ones”, originating from our countries, give only disappointing plants? It was that we had mixed tetraploid plants, the "new", with diploid plants, the "old". Hence the production of triploid plants (one batch of chromosomes from the diploid parent and two batches of chromosomes from the tetraploid parent), which are almost always sterile. And if later crosses proved to be superb and fertile, it was because they were, always accidentally, tetraploid, due to an unreduced gamete in a diploid parent. But no one was aware of this in the 1890s at the time of the attempts of Foster and his followers.

Fortunately, the accident described above has occurred often enough for the tetraploidy of the Amasya iris to settle down in a stable fashion and for the varieties obtained from the 1920s to be all tetraploid and to combine the qualities of the iris from Anatolia and those of European hybrids, giving birth to the irises that we know today.

This is why we owe so much to the plants harvested by the missionaries evangelizing the confines of the Ottoman Empire. This is why the region of Amasya and the banks of the Iris river (what a coincidence!) Can be considered as a cradle of modern iridophilia.



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