552 Reading-Course for Farmers. 



The individual the unit of breeding 



The unity of the individuals is also an important factor in plant-breed- 

 ing. If, for instance, one is attempting to produce a seedless fruit, it is 

 important that he discover a plant which shows a tendency to produce 

 seedlessness throughout the entire individual. It would not be the 

 correct policy for a breeder to select simply a single fruit which might 

 accidentally be nearly seedless. He should examine a large number of 

 fruits of different individual plants, and find a plant on which he can 

 discover a general tendency toward seedlessness, showing in all of the 

 fruits produced. By selecting seed from such individuals he may be 

 able to find in time one such individual that will transmit to its prog- 

 eny this tendency to produce few seeds. 



Test of transmitting power 



A factor of primary importance in all breeding is the testing of what 

 is termed the transmitting power. It is necessary for us to know that 

 a certain plant, which for instance, gives a heavy yield, has the faculty 

 of transmitting this tendency of producing heavy yield to its progeny. 

 It is frequently found that two select plants which are equally good 

 so far as their yield is concerned will give progeny which, as a whole, 

 differ greatly in this respect. In the progeny of one, almost every plant 

 may have inherited the quality, while in the progeny of the other only 

 a few of the plants may show in any noticeable degree the inheritance 

 of the quality. To determine this prepotency or transmitting power, 

 it is necessary to carefully grade the progeny of each individual, and 

 this is the primary reason for planting the progeny of differentindividuals 

 in separate rows or separate plats, so that they may be easily examined. 

 It would seem to be an easy matter when we plant the progeny of dif- 

 ferent plants in rows or small plats by themselves to get the compara- 

 tive yield, for instance, of from 25 to 100 plants, and from this to figure 

 up the average per cent of the transmitting power. 



Control of parentage 



In plant-breeding, as in animal-breeding, the isolation of the parents 

 is a very important consideration. It is necessary that we should know 

 the character of both parents wherever this is possible. In breeding 

 plants, most attention is ordinarily given to the mother plant, and 

 in very many instances the characters of the father plant are entirely 

 neglected. Animal-breeders, on the contrary, give more attention to 

 the characters of the male parent, and a great deal of improvement ir^ 



