Table 6. Effect of PPD1 gene combinations on heading dates in the field experiments.
| PPD-A1, PPD-B1, and PPD-D1 allele combination | Predicted phenotypes | Day of the year | ||||
|---|---|---|---|---|---|---|
| LA12 | GA12 | NC12 | NC13 | NC14 | ||
| A1a, B1a, D1a | I,I,I (21) | 73.5 | 80.4 | 88.4 | 108.2 | 116 |
| A1a, B1b, D1a | I,S,I (26) | 72.2 | 79.6 | 87.6 | 107.2 | 115.4 |
| A1b, B1a, D1a | S,I,I (27) | 74.7 | 80.3 | 88.6 | 108 | 116.2 |
| A1a, B1a, D1b | I,I,S (25) | 75.8 | 81.9 | 89.4 | 108 | 116.3 |
| A1b, B1b, D1a | S,S,I (24) | 76.1 | 82 | 89.5 | 108.2 | 116.3 |
| A1a, B1b, D1b | I,S,S (21) | 77.6 | 82.4 | 91 | 109.3 | 118.3 |
| A1b, B1a, D1b | S,I,S (16) | 80.8 | 84.6 | 93.1 | 110.1 | 117.5 |
| A1b, B1b, D1b | S,S,S (17) | 88.8 | 92.8 | 105.2 | 118 | 120.1 |
| LSDa | 2.5 | 2.0 | 2.3 | 1.8 | 1.3 | |
Mean heading dates for AGS 2000 × 26R61 recombinant inbred lines having different PPD1 gene combinations when grown at Baton Rouge, LA, 2012; LA12, Plains, GA, 2012; GA12 Raleigh, NC, 2012; NC12, 2013; NC13, 2014; NC14. Alleles with "a" designation confer day length insensitive phenotype (I) and "b" alleles are associated with day length sensitivity (S).
a LSD = Least significant difference (p<0.05).