Study On Flowering Regulation And Photoperiod Flowering Related Genes In M. Sacchariflorus

Miscanthus sacchariflorus is one specie of Miscanthus Anderesson, perennial C4 plants. Which were widely distributed in northern China. It has strong resistance to cold and drought and it is main stress-resistance breeding in Miscanthus germplasm. In his study through the study on photoperiodic flowering and photoperiodic regulation and photoperiod-related genes in M. sacchariflorus, aiming at flowering regulation which lay the foundation of cross-breeding, reached the following conclusions:1、When M. sacchariflorus were transplanted from high latitudes places to lower latitudes place Changsha, its flowering time focused from back of August until October in original place, after transplanted in Changsha its flowering time advanced to the late May last the end of June. Transplanted from high latitude place to low latitude place M.sacchariflorus flowered earlier, performance as a short-day plant.2、Through the flowering phenology observation of 10 materials of M.sacchariflorus which were transplanted in Changsha from higher latitude place found that 10 materials which grow after stems were cut their booting time were 41.77 days in average, the shortest was 25 days, the longest was 56 days, different genotypes was significant differences. It indicating that cut stem for newborn materials is a way to regulate flowering time.3、M. sacchariflorus will not flower untill the number of sections reach ten. The main stem length and the largest leaves length are very significantly correlated with flowering time and flowering percent. However partial correlation analysis show that the main stem length and the largest leaves length are not correlated with flowering time character, the number of sections and the main stem length have correlated with flowering percent, and flowering time related character are very significantly correlated with each other.4、M. Sacchariflorus B0232L grow under different natural light condition 8h,15h,16h, 17h,18h and and natural light condition(July- August) as a control after stem were cut, then found that M. sacchariflorus were booting in 48 days under natural light condition, in 56 days under short-day conditions, were not booting when the illumination time were longer than 15h. That means when the illumination time are longer than 15h M. Sacchariflorus will not flower or flower delay, and short-day is good to flowering induction.5、Homologous gene cloning method was used, two homologous FT gene were cloned in M. sacchariflorus, both are full length cDNA sequence, coding a open reading frame respectively, named them MsFT1 and MsFT2 respectively. Sequence comparison found that MsFTl and MsFT2 gene have high homology with other plants’ FT gene. One homologous partial cDNA sequences of CO were cloned, named MsCO. Sequence comparison show that MsCO gene have high homology with other plants’ CO gene.6、RT-PCR detection of MsCO and MsFTl found that MsCO abundantly expressed in the leaves and leaf sheath, a certain amount of expression in stem; MsFT1 only expressed in leaves. Both MsCO and MsFT1 have high expression under short-day conditions, very low expressed in long-day conditions.