4 i2 THE WHEAT PLANT 



At first the crossing was of a simple character between two kinds of 

 wheat, the grains of the hybrid plant being sown and selection made from 

 the progeny. Later, Farrer in Australia, Jones in America, and the 

 Carton Brothers in England resorted to multiple crossing, the first hybrid 

 being immediately crossed with a third form, and the plant produced 

 crossed with another wheat, successive hybridisations with different 

 forms being continued for several seasons. 



The following is an example of such multiple crossing, from which 

 the Australian wheat Bunyip was derived : 



Blount's Lambrigg x Hornblende 



Improved Fife x Purple straw An unnamed hybrid x King's Jubilee 



Rymer ? MafTra 3 



Bunyip. 



In the majority of cases there was little or no system in the choice of 

 parents of these simple multiple hybrids, the chief object being to obtain 

 immediate variation, and wheats chosen at random frequently gave satis- 

 factory results from this point of view. 



Farrer and others, however, first obtained a clear conception of the 

 desired improvements, and selected the plants to be crossed only after a 

 careful study of their morphological and physiological characters, in some 

 instances subjecting the parents to pedigree culture before hybridisation. 



Although the methods of the early hybridists were of a somewhat 

 haphazard nature, they led to the production of many valuable wheats, 

 among which may be mentioned Vilmorin's Bon Fermier and Dattel, 

 Pringle's Defiance, Jones's Winter Fife and Early Red Clawson, Saunders's 

 Marquis and Preston, and the Australian wheats Federation and Come- 

 back, produced by Farrer. 



Before 1900 the result of hybridisation was a matter of chance and its 

 nature could not be foreseen, since no reliable generalisations were avail- 

 able regarding the transmission of the characters of the parents to their 

 offspring in the case of sexually produced plants. 



About the date mentioned the rediscovery of the Mendelian laws of 

 inheritance removed some of the uncertainty of hybridisation, and the 

 plant-breeder is now able to predict with a high degree of assurance the 

 character of the offspring derived from the crossing of parents possessing 

 certain morphological and physiological features. 



Many of the characters of the wheat plant, such as the presence or 

 absence of awns, the colour of the chaff and grain, the hairiness and 

 smoothness of the chaff, and the solid or hollow condition of the straw are 

 dependent upon single Mendelian factors, which are transmitted from 

 parent to offspring independently of each other, and the plant-breeder is 



