5i8 BIOLOGY AND HUMAN LIFE 



Hybridize plants having desirable qualities 

 Inbreed hybrids for segregation 



Try out third generation for combinations that are pure 

 Multiply by seeding the true breeders ; destroy all others 

 Select hybrids that are worth keeping 

 Propagate vegetatively 



QUESTIONS 



1. How do the common vegetables in use today differ from those 

 used a generation ago ? 



2. How do the common fruits in use today differ from those used a 

 generation ago ? 



3. How are the changes brought about ? 



4. What advantages has the plant breeder over the animal breeder ? 



5. What are the necessary steps in establishing a new breed of plants ? 



6. Are all the new plants superior to all the old ones ? 



7. Why are different varieties of wheat grown in different parts of 

 the wheat-growing region of this country ? 



8. Why are different varieties of fruit grown in different parts of the 

 areas that produce the same kinds ? 



9. What advantages have come from Mendel's discoveries? 



REFERENCE READINGS 



OsTERHOUT, W. J. V. Experiments with Plants, chap, x, Making New 

 Kinds of Plants. 



Jewett, F. G. The Next Generation, chap, iv, Mendel and his Garden 

 Peas ; chap, v, Laws of Inheritance put to Use. 



Farmers^ Bulletin 1243, Strawberry Varieties in the United States. 



Farmers^ Bulletin 1332, Seed Potatoes and How to Produce Them. 



United States Department of Agriculture. Bulletin ig^. Potato Breed- 

 ing and Selection. 



United States Department of Agriculture. Bulletin 1192, Improvement 

 of Wheat by Pure-Line Selection. 



United States Department of Agriculture. Bulletin 1209, Effects of 

 Selection on Yield of Corn. 



