Maize genetics in the U.S.S.R.

American maize geneticists will be glad to learn that an active group of workers in maize genetics is springing up in the U.S.S.R. This work is under the direction of M. I. Hadjinov. We have received the following letters from him which are transcribed here for your information.

"Your letter of November 13, 1933 I received only 13th January, 1934. I am enclosing herewith information about our works on the maize genetics. I hope it will be of some value though strongly delayed.

During the last 2-3 years we have carried out this work some results of which will be shortly published. The greater part of them I am sending you today.

I should be much obliged if you would kindly send me the mimeographed circulars of the Cornell University on maize genetics and also some genetics stocks.

I should like to ask you if you would find it possible to send me also numbers of circulars previously years of which I possess only that of 1930 "Linkage in Maize".

I wish to state that I am familiar with the Chromosome Map in the report of Prof. R. A. Emerson on the VIth Genetic Congress.

Dr. G. D. Karpetchenko asks me to send his best wishes to you.

Yours sincerely,
(Signed) M. I. Hadjinov."

The enclosure:

"Recurrences of known mutations

• liguleless. From 7 stocks: Shanghai, Primosky Region (F. East) 2 different stocks, Middle Volga region, Armenia, U.S.A. Leaming (all tested) and one from the N. Caucasus (nontested).
• ramosa. From 4 stocks: Italy, 2 different stocks of Georgia, N. America (tested).
• shrunken. From 2 stocks: Middle Asia, North America (varieties Minnesota 23) (tested).
• golden₁. From West China (tested).
• green striped. From 2 stocks: Georgia, Leaming (non-tested).
• Teopod. From early sugar varieties (names unknown) supplied by Prof. Larionow from Ukraine, where Teopod has never been grown before.
• fine-striped. From 2 stocks: Mexico, N. America (tested).
• anther ear. From 2 stocks N. America (non-tested).
• dwarf₁. From 2 stocks (tested).
• dwarf₃. From 1 stock (tested).
• barren-sterile. (Prof. Hayes). From Spain (non-tested).
• barren-stalk. (Prof. Emerson). From Italy (non-tested).
• tassel seed₁. From 2 stocks. Primorsky Region, N. America (tested).
• tassel seed₂. From 2 stocks. Georgia, Armenia (tested).
• lazy culm. From Ivory King (N. America) (non-tested).
• brown midrib. From 2 stocks: Georgia, Sterling (N. America) (non-tested).
• 4 cases of cytoplasmatic male sterility: Azerbaijan, Peru, N. Caucasus, America.
• male sterility. 25 stocks segregated for male sterility are being studied.

 

New genes

1. Rh₁ Rh₁. Rough sheaths₁. A dominant gene producing warts in the leaf sheaths in the lower part of the leaf blade near the auricole. This character appearing in the plant in the stage of 7 to 8 leaves. The vitality of the plant is normal. Seed available.
2. rh₂ rh₂. Rough sheaths₂. A recessive gene producing the character similar to that of Rh₁ Rh₁. Beside warts this gene causes sometimes a narrowing of the leaf blade and the appearance of thread-like leaves. The vitality of the plant is somewhat low, but in some families normal. Seed available.
3. gl₄-gl₁₁. Glossy_4-11. 11 different allelomorphs gl₁-gl₁₁ have been recorded from 25 different stocks. Among the 11 genes of glossy by intercrossing and linkage there have been found gl₁ - gl₃ previously described. The linkage of the remaining genes will be shown below.
4. cr₂ cr₂. Crinkly. A gene similar to crinkly₁ but nonallelomorphic with it. Seed available.
5. yg₄ yg₄. Yellow-green_3-4. Duplicate genes. The seedlings are yellow-green till the flowering stage. After the flowering the yellow pigment disappears. It segregated as a simple recessive gene in the original stock. In crossing with non-allied families gives 15:1. The vitality of plant is extremely low. Seed available.
6. rs-rs. Ramosa-silkless. This gene causes a branching of the ear similar in appearance to ramosa but with the complete absence of silks. At the same time it causes an, in the tassel, increasing of glumes, flower spikelets and anthers in the pair spikelets. It gives a normal pollen. The vitality of the plant is normal. Seed available.
7. at at. Antherless. Causes a complete absence of anthers. The vitality of the plant is normal. Seed available.
8. hf hf. Hermaphrodite flowers. A pistilate flower is developed in the male flower beside anthers giving a silk 2-3 cm. long. Sometimes instead of a silk there is only a rudimentary pistil. The pollen is very rarely developed. The ears have a low fertility. The vitality of plant is normal.
9. vb vb. Variable brachyte. Causes a sharp shortening of the internodes up to 1 cm. This character is much variable. This shortening may affect either a considerable part of internodes in what case it produces a dwarf plant, or only a part of internodes. Very often the shortened internodes alternate with the normal. Non-allelomorphic with brachyte.

The allelomorphism of vb vb with brevis will be stated in summer 1934. Seed available."

 

In answer to my reply to the above letter the following was received:

"I have received your kind letter and mimeographed circulars. I am very grateful to you for information and multiple testers which you are sending me. The connection I am trying to establish with you and which, I trust, will be strengthened in future will greatly help us in our work on maize genetics, which I am carrying on now. I hope not to be soon the only worker on maize genetics in U.S.S.R. because I try incorporate into it a considerable number of persons carrying selectional work in corn Inbreeding. These workers introduce up to 10-12 thousand new self pollinations every year. Without close association with you our work would be extremely difficult.

In regard to your observations on new mutation characters I am going to say the following:

1. I agree with you that Rs₁ and rs₂ are better symbols for Rough sheath₁ and rough sheath₂. I gave them symbols Rh₁ and rh₂ because by rs I have designated ramosa-silkless which, as I read shortly in the Journal of Heredity seems to be similar to 'branched silkless' bd.
2. I hope to come to an agreement with Dr. Sprague regarding the allelomorphism of Dr. Sprague and my glossies.
3. My crinkly is non-allelomorph cr₁. A limited generation of F₂ from crossing + + c₃/sh wx + shows that it is not located in 9 chromosomes and thus seems non-allelomorph cr₂ of Dr. Eyster. I will designate it by cr₃.
4. Genes yellow green_3,4 - duplicate genes which you think to be similar to au_1,2 of Dr. Eyster will be tested in linkage with the genes wx and C. I have these F₂.
5. My ramosa-silkless is similar to branched-silkless of Dr. Kempton. My data, however, on linkage (bd) do not coincide with those of Dr. Kempton, who believes it (bd) to be located in 4 (su-Tu) chromosome.

The table below shows my

Progeny	Phase	Genes	Number of Plants				Total	Crossover Per cent
			BdX	Bdx	bdX	bdx
F2	R	Susu	728	159	227	42	1156	47.6�1.53
F2	C	Tutu	102	33	41	8	184	57.0�4.01
F2	R	Bnbn	252	143	101	19	515	34.7�2.55
B	R	Bnbn	9	41	15	6	41	36.6

which induce me to think (bd) located in 7 (ra-gl₁) chromosome. This summer I shall have the linkage (bd) with larger progeny.

6. I have genes ts₁, ts₂, ts₄ and I am aware of the genes Ts₃. All these genes produce grains on tassels and in ts₁, ts₂, ts₄ there is nearly always a complete replacement of male flowers by female. Ts₃ produces also grain on the tassel.

A small ovary with a sport silk or without it is developed in the hermaphrodite male flowers in which seeds are never formed. Anthers are nearly normal, but pollen degeneration occurs soon after tetrads during the formation of pollen walls. hf is associated with a strong sterility of female flowers, hf - is not linked with su. I have sent you the drawings of hf male flowers.

At the same time I am sending you small quantity of seed Rs₁, rs₂, cr₃, at, hf, vb, bd, ra and my gl₂, gl₃, gl₅, gl₆, gl₇, gl₈, gl₉, gl₁₀. In autumn I will forward a series of characters after testing their mode of heredity.

Some time ago I read your paper on plasmatic sterility in the Journal of Genetics. The results which I obtained and mentioned at the time in my letter to Dr. Karpetchenko, then in Pasadena, are completely identical with yours. The experiments with artificial infection of seedlings by fresh juice from flowering ears showed me, as in your case, negative results. I am, however, inclined to consider this phenomenon as a result occasioned by the virus diseases. Presently in connection with investigations of the Mendelian type of male sterility from 35 different sources I came upon 4 cases of plasmatic sterility. One type of plasmatic sterility inherited in F₁ through pollen I have in sorghum. I am studying it presently. In regard to the work of the Mendelian type of male-sterility I have got myself in connection with Dr. Beadle, through whose kindness I received all his genes of male sterility.

With best wishes, I am
Sincerely yours,
(signed) M. I. Hadjinov."

Unfortunately the seed Hadjinov sent was received too late for planting here at Ithaca last summer. Next fall, however, we shall have seed available for distribution.