COWPEAS, SOYBEANS, AND VELVET BEANS 



147 



time of maturity are characters which have been widely used in 

 varietal and group classifications. 



Little work has been done on the inheritance of characters in 

 soybeans. Beans with green cotyledons may have green seed- 

 coats, while beans with yellow cotyledons may have either green 

 or yellow seed-coats. 1 H. Terao (1918) of the Imperial Agricul- 

 tural Experiment Station, Tokyo, Japan, has discovered that 

 in a cross of green cotyledons, green seed-coats 9 X yellow 

 cotyledons, yellow seed-coats d 71 the inheritance of the green 

 seed-coat apparently was matroclinal; likewise the inheritance of 

 the character of the cotyledons. In the reciprocal cross the 

 character of the cotyledons again proved matroclinal in inherit- 

 ance but the seed-coat character segregated as a monohybrid 

 with green dominant. In explanation of these facts it is assumed 

 that the two kinds of chlorophyll concerned differ in that one re- 

 mains green (G) and the other turns yellow (F). It is further 

 assumed that the inheritance of these conditions in the cotyledons 

 is through the cytoplasm or chromatophores and not through 

 the nucleus. In the case of color of seed-coat a Mendelian factor 

 pair is involved. When H is present it prevents the chlorophyll 

 (Y) in the seed-coat from changing to yellow. When this factor 

 is absent the small letter h is used. 



Table XXXI II. taken from Terao illustrates four possible 

 combinations. (G) and (Y) are transmitted only through the 

 cytoplasm of the egg cell. 



TABLE XXXIII. INHERITANCE OF COTYLEDON AND SEED-COAT COLOR 



1 Black and brown pigments also appear in the seed-coats of certain 

 varieties. These pigments are entirely independent of the green and yellow 

 colors but they make the green and yellow colors indistinct. 



