292 NEW JERSEY AGRICULTURAL COLLEGE 



A Study of the Heredity and Correlation of Structures 



m Tomatoes. 



REPORT OF PROGRESS. 



The ten types of tomatoes known as Currant, Cherry, Plum, 

 Pear, Fig, Peach, Dwarf, Potato Leaf, Ponderosa and Oligos- 

 perm are being- studied microscopically as to the nature of their 

 differentiating structures. The results of the study of their 

 fruit skins were published as Bulletin 228, and similar work 

 is under way on characters of leaves and stems. 



Crosses were made in the greenhouse, in the winter of 1909- 

 1910 between all of these types, excepting the oligosperm, which 

 could not be crossed with any other type. They resulted alto- 

 gether in 36 fruits of the possible type combinations, with 33 of 

 their reciprocals, and 15 alternatives, i. e. combinations of dif- 

 ferent fruit colors of the same types. Besides there were 21 

 duplicate or triplicate fruits. All the seeds of all except a few 

 triplicate fruits were sown in rows in boxes in the greenhouse 

 and the seedlings studied minutely as to fluctuation in the 

 shape of the cotyledons and first leaves, and compared 

 with the fluctuations of seedlings of the parents. Then the 

 plants, a total of about 5,600, were set out, twO' and three in a 

 hill on fourteen plots of the Home Grounds and parts of Strip 3 

 of the New Grounds. 



In this F^ generation a study was made of the heredity of the 

 habit of the plants, the size of the stem, size and shape of 

 leaf, hairiness, size, color, shape, and cell number of fruit, form 

 of cluster, and number of flowers to the cluster. All the data 

 were obtained by measurements and counting of large numbers. 

 Specimens were preserved for later microscopic study. 



Many self-fertilized fruits were obtained from each set of 

 crosses for the next generation. 



The details of the experiment will appear shortly in form of 

 bulletins. It was possible to confirm the fact that the color of 

 fruit skins exhibit in the F^ complete dominance, and it was ap- 

 parent that 



1. There is in the F^ of tomato hybrids no apparent domi- 

 nance of size or shape, of stems, leaves or fruit. 



2. Reciprocal crosses between the identical parent plants 

 may give different characters in the two sets of Fj plants. 



