Meister: Natural Wheat-Rye Hybrids in Russia 



469 



intermediate type, with a larger or 

 smaller number of rye features. All 

 the hybrids, with the exception of 

 two which were typically r\e, had 

 wheat seeds and many-nerved empty 

 glumes. 



In many hybrids the blooming is not 

 normal. Blooming with widely open 

 flowering glumes predominates; some- 

 times the anthers do not crack and 

 have a small amount of pollen. A 

 good deal of the pollen is amorphous. 

 In several plants a certain discord in 

 the organs was noticed for example 

 green anthers were thrown out on 

 long threads and then faded, etc. 



As regards the fertility of hybrids: 

 typical rye and typical wheat plants in 

 most cases have a normal fertility, but 

 several plants with ears of the square- 

 head type are all sterile. The fertility 

 of the other plants definitely falls as the 

 rye features increase. 



The following are the figures for 

 fertility: 29 per cent entirely sterile 

 plants; 42 per cent with one grain 

 each; 11 per cent with normal fertility; 

 the remaining 18 per cent occupy an 

 intermediate position. All the more or 

 less new or original morphological forms 

 are either sterile or bear single seeds. 



The new features established are: 

 the narrow, needle-pointed shape of the 

 leaves; thick leaves; great brittleness 

 of the rachis of the ear; very rough 

 awns; thick stems and other features as 

 enumerated above, which indicate a 

 strong deviation from paternal forms. 



In the third and fourth generation 

 we have, obviously enough, almost 

 exclusively either typical rye or typical 

 wheat plants, to which we shall confine 

 ourselves, as there were too few 

 hybrids of the intermediate type in 

 these generations. First of all we 

 must point out that Fi hybrids 

 whether typical rye or typical wheat 

 continue their form into future genera- 

 tions. This constancy, it seems, is 

 characteristic also of the plants of 

 intermediate type. Within these fixed 

 basic forms was noticed only the 

 segregation of individual features. 

 Thus, for example, in one wheat family 

 a simple Mendelian segregation of 1 : 3 

 occurred with respect to presence 



and absence of awns; in three families, 

 with respect to hairiness of the upper 

 part of the culm the total numbers 

 gave the approximate ratio 1:15. In 

 other features nothing approximating 

 any fixed segregation could be estab- 

 lished. 



In the third generation we have 20 

 per cent entirely sterile plants or with 

 one seed only, and 53 per cent normal 

 plants, sometimes with very good 

 seed. 



Now comes the question : If in segre- 

 gation we notice the separation of two 

 basic forms of the Triticum and Secale 

 plants, what about those properties 

 which regulate their frost resistance? 

 We are not yet in a position to give a 

 definite answer to this question. Con- 

 sidering the presence in plants of 

 several symptoms of opposing mor- 

 phological features, we have no reason 

 for denying the possibility of similar 

 phenomena in the physiological pro- 

 perties of the plants. But, so far we 

 must confine ourselves to quoting 

 several appropriate facts. 



In the winter of 1920 the hybrid 

 plants were kept in a special hothouse 

 at a temperature of 1° — 2° C. This 

 temperature proved particularly favor- 

 able for the growth of the fungus 

 Fusarium nivale. The hybrids were 

 planted in boxes containing 45 plants 

 each. In one r>'e family 96 per cent 

 of the plants perished from fungus, and 

 as one box was planted only partly 

 with rye and the rest with another 

 wheat family, we were able to note in 

 the latter the complete absence of 

 attacked plants. The absence of the 

 mycelium of this fungus was noted in 

 four families of the wheat type, in 

 fifty-five families the destructive fungus 

 was present in from seventeen to 

 sixty-two per cent of the plants, and in 

 113 families there was a slight blight 

 on the plants with but small loss; 

 characteristic segregation was noted 

 in susceptibility to Fusarium nivale. 



Leaving aside for the time being the 

 question of the difference in sus- 

 ceptibility to the fungus Fusarium 

 nivale of the parent forms — a question 

 that has not been cleared up by us — - 

 we can, so far, on the basis of the 



