6 



BULLETIN 971, U. S. DEPAETMENT OF AGRICULTURE. 



Table I. — Measurements of the tassel characters of the Ramosa and Oordo 

 varieties of maize compared with those of the first and second generations 

 of their hybrids. 





Measurements of length (centimeters). 



Number of 

 branches. 



Central 



designation. 



Entire. 



Branching 



space. 



Central 

 spike. 



Uppermost 

 branch. 



Lowest 

 branch. 



spite 

 index. 



Parents: 



Ramosa 



Gordo 



Combined Fii 



Combined F2: 



Normala 



Ramose a 



Mhl57Fi 



Mlil58Fi 



MI1I59F1 



MI1I57 F2: 



Normal 



Ramose 



Mhl58 F2: 



Normal 



Ramose 



Mill 59 F2: 



Normal 



Ramose 



32.6±0.37 

 30. 5±0. 33 



47.7 



38.4 

 33.5 



47.1 ±0.48 

 48. 6± 0.33 

 46. 0± 0.43 



33. 7±0. 27 

 29.6±0.39 



40.3±0.39 

 35. 2± 0.50 



43. 2± 0.39 

 38.1 ±0.66 



27.7±0.32 

 5.1±0.14 

 10.7 



8.3 • 

 21.7 



10. 7 ±0.28 

 10. 8± 0.16 

 10. 5±0. 23 



8.4±0.12 



19. 8 ±0.36 



8.0±0.26 

 24. 3±0. 57 



8.6±0.21 

 28. 2 ±0.62 



6.0±0.23 

 25.1 ±0.30 

 36.7 



30.0 

 10.3 

 36. 3±0. 55 



37. 6 ±0.28 

 35. 6±0. 30 



24.9±0.21 

 10. 0±0. 25 



32. 4±0. 55 



10. 7 ±0.30 



34.5±0.37 

 10.0±0.60 



1.8±0.05 

 15.4±0.21 

 21.8 



17.3 

 3.1 



22.0±0.39 

 22. 2 ±0.26 

 21. 2±0. 38 



14. 8±0. 18 

 3.3±0.21 



18.3±0.46 

 2.9±0.11 



19.5±0.28 

 3.4±0.20 



20. 7 ±0.31 

 19.4±0.30 

 28.0 



22.3 

 17.6 



26.7±0.51 

 28. 4± 0.30 

 28.1 ±0.45 



18. 4± 0.24 

 14.4±0.26 



23. 4± 0.55 

 18. 6 ±0.46 



27.3±0.44 

 22.8±0.72 



133.7±3.69 

 7.0±0.23 

 14.4 



13.4 



58.9 



17. 4±0. 83 



11.8±0.30 



16.6±0.44 



19. 2± 0.35 

 60. 4±0. 16 



10. 0± 0.37 

 55, 2± 1.51 



10. 3± 0.32 

 66.0±0.70 



15.5±0.58 

 83. 4± 0.43 

 77.6 



77.4 

 30.8 



77. 0± 0.74 

 77. 7 ±0.30 

 77. 9 ±0.57 



73. 6± 0.33 

 32. 8 ±0.69 



80.1 ±0.62 

 30.5±0.79 



78.7±0.45 

 25.3±1.24 



a The several progenies were combined for purposes of inspection only, and therefore the probable errors 

 were not calculated. Asa close inspection of the table will show, sister progenies differed in some charac- 

 ters by amounts too large to be ascribed to chance, and therefore the combined progenies do not constitute 

 a homogeneous population . 



When the ears 

 were harvested the 

 variability in the 

 expression of the 

 ramose character 

 was even more 

 striking. PI a n t s 

 classified as ra- 

 mose from the 

 characteristics of 

 their tassels bore 

 ears which ranged 

 in a continuous 

 series from un- 

 branched cobs to 

 the typical rami- 

 fied inflorescence 

 (fig. 4). The un- 

 branched ear pro- 

 duced on a ramose 

 plant is shown in 

 Plates IV and V, 

 while some of 

 the intermediate 

 stages are shown 



so 



I 



I 



SO 



to 



JffS9A/0F 

 A/0/?M/9L 



^ '1 



MS/fA/OF 



f»' S 



SJ"> 



lOJU. 



1 1 1 1 I I 1 1 1 1 



■ 



uJtL 







n 



20 



dO 



W 



SO 



eo 



70 



80 



30 



WO 



/ 



II 



Zf 



31 



^ 



SI 



61 



71 



81 



SI 



lot 



Fig. 2. — Frequency distributions with respect to the cen- 

 tral spike index in maize plants of the second hybrid 



■ generation of Ramosa-Gordo. The square marked with 

 a cross represents a plant classed as ramose. 



