Sax and McPhee: Bean Hybrids 



207 



o>. y. £ 



3. /.e. 



^ 



^, 



\ 



/ 



CROSSING EYED BEANS 



Figure 8. The cross, Old-Fashioned Yellow Eye X Improved Yellow Eye, results in 

 "piebald" beans in the first hybrid generation which have over twice as much pigmented area 

 as either parent. The second generation ratio is 1 O. F. Y. E.: 2 piebald : 1 /. }'. E. The 

 two alellomorphic factors for eye pattern when heterozygous cause a greatly increased ex- 

 tention of pigment, and an entirely new eye pattern. Photograph by C. H. White. 



background is grey or light purple. 

 The eye may be very definite in out- 

 line as in the /. Y. E., or it may 

 blend gradually into the white or pig- 

 mented background. 



The great variability of the second 

 generation segregates in crosses of 

 eyed with white beans is shown in 

 Figure 7. The color of pigment in- 

 cludes black, brown, yellow, purple, and 

 red with a large series of intermediate 

 shades. Numerous types of mottling 

 are also found. The mottled pattern 

 may consist of small irregular patches 

 on a pigmented background or the 

 background may be white. Often 

 several mottling patterns are super- 

 imposed on one another. The patches 

 of pigmented area may be of various 



shapes and sizes. In some cases the 

 mottling pattern is associated with 

 sunken areas of the seed coat. The 

 uniformly pigmented beans also show 

 great variability in color of pigment. 

 In the second generation a large series 

 of eye patterns are obtained ranging 

 from individuals with more than ninety 

 per cent of the seed coat pigmented 

 to segregates which have only a small 

 dot of pigment at one end of the hilum. 

 In crosses oi I .Y. E. X White involv- 

 ing several thousand second generation 

 segregates the /. Y. E. parental type, 

 in respect to size, pattern, and color, 

 was rarely if ever recovered. 



It is also found that factors for seed 

 weight are associated with factors for 



