The Situation in Biological Science (1948)
Prunus hybrids
F. K. Teterev

Any good variety may be ruined if the proper conditions are not created for it.

Another example: Bellefleur-Kitaika, in our parts, where the conditions are not suitable for it, sometimes bears a poor crop; but around Krasnodar and in the Crimea, where the conditions are good, it bears a fine apple with a candy taste, similar to the apples which Michurin obtained from it.

The same may be said of many other varieties, even longstanding ones. If we create the necessary conditions for their growth and development, we undoubtedly obtain good results.

*Elista, capital  of Kalmykia: In 1944-1957, it was referred to
as the town of Stepnoy within Stavropol kray of Russia.
†Vladimirskaya = 'Vladimir' morello, sour cherry

One of my jobs is to experiment in the intergeneric hybridization of stone fruits. In 1934-35, we obtained a hybrid by crossing the Vladimirskaya cherry with the Stepnoy* almond. Quite by chance, as happens with the formal geneticists, the hybrid turned out to have 24 chromosomes, although a number of the seedlings were found to have another chromosome number. The haploid number of the almond is 9, that of the Vladimirskaya† cherry is 16, yet the hybrid had 24 chromosomes. It blossomed profusely, but bore no fruit. But when this hybrid was grafted on to a sour cherry, it blossomed and began to bear fruit. More, when this hybrid was grafted on to a sweet cherry, it even began to bear quite abundant fruit. In taste, it is a spoilt Vladimirskaya (to use Lysenko's expression), but that is not the point. The important thing is that this hybrid between a sour cherry and the Stepnoy almond normally bears fruit under the influence of mentors, although it has only 24 chromosomes, in other words, is an illegitimate hybrid, in the view of the formal geneticists.

Not only hybrids of sour cherry and almond and hybrids of bird cherry and sweet cherry, but other interspecific hybrids, which "according to the book" ought not to bear fruit, do bear fruit if only the necessary conditions are created for them.

As we know, there are many workers on distant hybridization; but, unfortunately, this work is often done so incorrectly as to be fruitless. B. M. Zavadovsky, for one, obviously has a muddled idea of the Michurinian doctrine. He said that the cornerstone of the Michurinian doctrine was hybridiation: The fact of the matter is that hybridization was practised long before Michurin, but it was only Michurin who began to create varieties by alteration and training. Before crossing, Michurin properly prepared the initial components, providing proper conditions for them, approximating them by grafting, destabilizing their heredity, and so on. Has Academician Zavadovsky forgotten Michurin's methods of preliminary vegetative approximation, the use of "intermediaries" and the like? Michurin always began by choosing and preliminarily preparing the two components, then crossed them, and completed the process of creating the variety by training the hybrid progeny.

That is where the crux of the matter lies, and not in hybridization, for Michurin always said (and I should know, since I worked with him) that the fundamental thing was proper choosing and proper preparation of the components, and as to crossing, any student, any schoolboy could do that.

Not every one has a knowledge of the methods of training and reforming, and not every one knows how to utilize them properly. The methods of agrobiological science are much more complex and intricate than the sketchy methods of Morganism. The formal geneticists used to say that distant hybridization was of no use whatever, and that such hybrids were sterile; but now they say that simple crossing is quite enough and you may get a distant hybrid by it. That is absolutely untrue.

One of the Morganists who spoke here mentioned the plum. I might give the following information on this score.

I had occasion to work with Dr. Rybin at the Maikop Station in 1929, when Darlington and Lawrence announced, with the usual Mendelist-Morganist style of approach, that if we cross the blackthorn with the cherry plum (Prunus cerasifera) we shall get the cultivated plum. Rybin went to the North Caucasus, where there is a great variety of blackthorn and cherry plum, and began to cross them, hoping to obtain the cultivated plum, although the plum is to be found in every orchard both here and in the South. Rybin's cherry plums produced their group of varieties, his blackthorns their group, and so forth. As the result of his labours, Rybin obtained sterile hybrids between the blackthorn and the cherry plum. Finally, in 1947, he announced in the Scientific Council that he had produced sterile, semi-fruitful, small-fruited and low-quality forms, but that, on the other hand, they were equal to the plum in chromosome number. And in 1948 Rybin planned to cross large-fruited forms of cherry plum and blackthorn, reckoning to obtain what he desired and then to proceed to breed it. But I think we, plant breeders, will cope with this task more effectively.