256 



GENETICS AND PLANT BREEDING 



those of the highly desirable mentors 

 grafted upon them. 



There is much more in this paper 

 of Michurin's written in the same loose 

 and, I fear, lightly-judged way, which 

 to some extent has flowed over into 

 Lyscnko's Soviet Biology. TTius Mi- 

 churin writes: "As to the famous pea 

 laws of Mendel, only very ignorant 

 people may think that they may prove 

 useful to the breeder of new hybrid 

 varieties of perennial fruits. Mendel's 

 law is not applicable to perennial fruit 

 trees, nor does it apply to annual hy- 

 brids, or if you wish, to kitchen garden 

 crops themselves." This is, of course, 

 rather an ironical statement. I have al- 

 ways considered the garden pea a 

 kitchen garden crop, and we know 

 many annuals whose characters behave 

 the same as those in peas. As to only 

 very ignorant people, it would indeed 

 be a ver)' ignorant person who would 

 expect vegetatively-propagated peren- 

 nials, such as fruit trees, which are in- 

 variablv heterozygous, commonly self- 

 incompatible, and hence cross-polli- 

 nated, to behave in inheritance precisely 

 the same as peas which are self-pol- 

 linating, reproduced sexually annually, 

 and, in consequence, in the main ho- 

 mozygous. Nevertheless my work and 

 that of my colleagues and others has 

 shown that there are many characters 

 in various perennial fruits, such as rasp- 

 berries, peaches, pears, etc., which in 

 inheritance behave the same as those in 

 peas. 



This paper also describes experi- 

 ments in breeding pears. One of the 

 most successful varieties used as a 

 parent appears to be the variety Beurre 

 Diet. Thus we are told: "This combi- 

 nation was a cross between Beurre Diel 

 and a young seedling of the wild usuri 

 pear flowering for the first time. Of 

 the h\'brids raised, two-thirds bore 

 fruits maturing in summer or autumn, 

 and one-third were hybrids producing 

 fruits that ripened in winter"; I read 



this to mean that 100 per cent of the 

 family were fertile, and if so this again 

 conflicts with my experience. Beurre 

 Diel is a triploid variety, and hence 

 with me it has not been a desirable par- 

 ent; on the contrary, and as one would 

 expect it has proved a bad parent. 



Following Lyscnko's advice I have 

 read all that has come my way on the 

 teachings of Michurin including Voks 

 Bulletin (1945). Here a certain Pro- 

 fessor Yakovlev, a Stalin Prize Winner 

 and Manager of the important Michu- 

 rin Nurseries, writes: "In his science 

 of vegetative hybridization which is 

 now being developed and expanded by 

 his talented follower T. Lysenko— 

 Michurin dealt a decisive blow to the 

 metaphysical views of the geneticists 

 Mendel and Morgan." There is noth- 

 ing, however, in his article which sup- 

 ports this now familiar and somewhat 

 vindictive statement. 



Professor Yakovlev then goes on to 

 what he calls intergenal hybridization 

 and writes, "for the first time in world 

 practice such fruit-bearing hybrids 

 have been produced in Michurinsk as 

 hybrids of apples and pear trees (by 

 T. R. Gorshkova), plum and peach 

 (by V. N. Yakovlev), cherr}' and plum, 

 red and black currants." I would point 

 out that Professor Yakovlev is not cor- 

 rect in this statement— plum-peach, 

 gooseberr}'-currant, pear-quince, peach- 

 almond and other hybrids have long 

 been known. 



The plum-peach hybrid I have re- 

 ferred to was raised by Messrs. Laxton 

 of Bedford, and was described bv them 

 in the Report of the Third Interna- 

 tional Conference on Genetics (1906). 

 It was raised from Prunus trifiora x 

 Amygdalis persica. I grew it for over 

 thirty years, and it was quite sterile. 

 I have also grown the peach-almond 

 for over thirty years; it crops well in 

 favorable seasons and produces good 

 seeds. The pear-quince was raised in 

 this country in 1895; in Algeria it pro- 



