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BREEDING CROP PLANTS 



TABLE LXI. LIST OF PISUM FACTORS, ALPHABETICALLY ARRANGED, AND 

 THEIR CORRESPONDING CHARACTER EXPRESSIONS 



Expression 



Salmon-pink or rose flower color. With CD gives reddish leaf axils. 

 Purpling factor plus A gives purple flowers. With CD plus A gives purplish 



leaf axils and stem bases. 



Glaucous foliage, stems and pods (with W); "bloom." 

 Pods with blunt apex. 

 With D gives leaf axil and stem color. 

 With C gives leaf axil and stem color. 

 With F and B gives purple dotting on seed coats: in the absence of B gives 



reddish dots. 



Modifies the expression of (Lf) toward earlier flowering. 

 With E and B gives purple dotting on seed coats; in the absence of li gives 



reddish dots. 



Axillary flowers, round stems, regular phyllotaxy. 

 1 to 2 flowers per peduncle. 

 Yellowish green to grayish brown seed-coat color (weak chromoseN factor), 



brown hilum. 

 Green cotyledon pigment. 

 Green pod color. 



Brightener or inhibitor of expression of (Gc.) 

 Factor which causes green cotyledon color to fade. 

 With (Gc) gives dark brown seed-coat color. 

 With Li gives indent peas. 

 With Li (A) gives indent or dimpled peas. 

 Long internodes; with T gives tall plants. 

 Primarily responsible for late flowering. 



Brown or maple mottling on seed coat; or "ghost mottling" in absence of A. 

 Violet eye on seeds. 

 Green foliage, stems, and pods. 

 Inflated, parchmented, nonedible pods with V. 

 With P-> gives purple pods. 

 With Pi gives purple pods. 

 Black-eyed seed-coat pattern. 

 Round, smooth seeds with simple, oval starch grains, low water content 



and with excellent powers of germination under unfavorable weather 



conditions. 



Pods with seeds separated or free. 

 Tall, robust plants, large number of internodes. 

 Leaves with tendrils. 

 Dark self-colored purple seed-coat. 

 With P gives parchmented. smooth pods. 

 With ( B1) gives glaucous foliage, pods. 



The presence and absence of these thirty-five factors are gene- 

 tically responsible for seventy or more differential characters. As 

 is noted in the table, there is a modifying effect of one factor upon 

 another in certain cases. Studies have also shown that certain 

 environmental conditions may modify a particular inheritance in 

 such a way that the true genetic nature can not be determined 

 by inspection. This is an instance which should help to impress 

 upon the student the necessity of the controlled breeding test as a 



