Abstract
To investigate the effect of heterosis between F1s (F1:First filial generation) and their parents, we investigated the differences of canopy surface temperature (Tc) among six sugar beet genotypes.
Three of the genotypes: “NK195BR”, “NK235BR” and “NK388” were tested as parents, while the other three “NK235BR×NK195BR”, “NK195BR×NK388” and “NK235BR×NK388” were tested as F1s.
The diurnal variation of Tc was maximal between 10:00 and 14:00. The maximum difference among genotypes was about 2.7 ℃ in daytime and the Tc of “NK195BR×NK388” showed the lowest among the other genotypes in 103 days after transplanting. The differences of Tc among genotypes increased with increasing vapor pressure deficit. Comparing the 6 hours mean Tc value of six genotypes from 10:00 to 16:00 and in descending order of its value, the results showed “NK388” > “NK235BR” > “NK195BR” > “NK235BR×NK195BR” > “NK235BR×NK388” > “NK195BR×NK388”. Although there was a trend that the yield of F1s was higher than that of their parents with high Tc, it is necessary to clarify the relationship between Tc and yield in the future.
