Three linked autosomal loci were studied in cucumbers: fruit color (dark vs. light), tendril size (long vs. reduced) and fruiting (normal vs. early). Pure breeding early fruiting light cucumbers with long tendrils were mated to pure breeding normal fruiting dark cucumbers with reduced tendrils. The F1 were testcrossed and the testcross progeny are given below. Time to Fruit Tendril Size Fruit Color Number Normal Long Dark 360 Normal Long Light 32 Early Long Light 753 Early Long Dark 28 Early Reduced Dark 24 Early Reduced Light 494 Normal Reduced Light 35 Normal Reduced Dark 975

Explanation:

1. Progeny observed in the experiment is calculated by adding all the progeny numbers observed in the :

TIME TO FRUIT                TENDRIL SIZE        FRUIT COLOR       NUMBER

 Normal                             normal                      dark                        370

 normal                              normal                      light                        32

 early                                  normal                      light                        971

 early                                   normal                     dark                         28

 early                                  reduced                    dark                          25

 early                                   reduced                   light                          483

 normal                                reduced                   light                          36

 normal                                reduced                    dark                         810

                                                                               TOTAL

                                                                                PROGENCY           2755

2. The locus in the center is TIME TO FRUIT. Tendril size is at the beginning of the locus and the distance between the locus B and locus C is R2