DWARFS IX GLUVAS EARL\' (WHEAT) HYBRIDS. 



541 



In general the cliaracters under discussion for the Rieti 

 are reflected in the dimensions given ; the same may be said for 

 the Gluyas Earl)-. (See Table I. a and /;. ) 



All the above-mentioned parent strains give rise only to 

 normal plants, if hybridisation does not intervene. 



Dwarfs ap})eared in the second filial ('F.2) generation. 

 Few of these dwarfs mature any seed, and as the research 

 is carried out with a \\q\v to producing economical wheat 

 varieties, these had to be discarded. It would perhaps be 

 interesting to establish whether this ap])earance of dwarfs is not 

 due solely to the effect of Gluyas Early when used as the paternal 

 parent, the more so as Rieti. the other parent in cjuestion, does 



■i^' 



Fig. r. — Frequency Curve for Height of Plant (cm.), s^a X 41^^- 



not give rise to any dwarfs in its progeny, except when hybridised 

 with Gluyas Early or perhaps a similar parent. 



For this purpose it may be well to refer to reciprocal hybrids 

 between Gluyas Early and Rieti. in \\hich the F.2 progeny 

 gave the following results : — 



36 X 41-2 out of 15 plants 3 dwarfs 



41-2 X 36* out of 16 plants 5 dwarfs. 

 i.e., out of 31 plants eight were dwarfs, immediately showing 

 that dwarfness is a true recessive, and that this recessive appears 

 no matter whether Gluyas Early be the maternal or the paternal 

 I)arent. 



* 36 = Rieti. This number 36 is a selection, therefore may be 

 regarded as a pure line ; tiius both parents used in this case are pure 

 lines, and future generations have ah-eady shown that they breed true ta 

 type. 



