The Physiological Mechanism Of Transportation In Sugar Beet(Beta Vulgaris L.)

Sugar beet (Beta vulgaris L.) was an endemic sugar crop and played an important role in agricultural production in north China. Yields of sugar beet were not high and the total output was instable, particularly sugar content showed a downward trend in Heilongjiang province and the national. All had become the obstacle factors to the development of sugar beet.Sugar beet was an endemic crop that storage large sucrose in hypertrophy main root.The mechanism of sucrose synthesize and transportation in sugarbeet leaves was clearly,because of the isotope technology widely application.However,there is little research and different opinions about the post-phloem transportation way of sucrose in root,By using radioactivity isotope trace technology way can trace the photosynthetic product transportation way on the phloem and post-phloem in root ,So it can according to whether the whole transportation way of phloem and post-phloem and storage tissue being a high to low 14C photosynthetic product gradient and the condition of this gradient increased or decreased with beet root growth. And further judge the whole transportation of sucrose enter into root to storage tissue,Especially judge whether the post-phloem transportation is the limited speed stage of sucrose transportation.So the purpose of this study is to reveal the transportation way of sucrose in beet root,and judge whether the post-phloem transportation is the limited speed stage of sucrose transportation.The result showed that :(1)The sugar content of beet root is sustainable increased with sugar beet growth.(2)Before the sugar beet complete mature, photosynthetic product of sugar sheath all account for 50% of beet root,and it is the centre of photosynthetic product distribution in beet root.And to the sugar beet complete mature,it is similar to other tissue that 14C photosynthetic product in sugar sheath,and there is no longer a significantly distribution center.(3)The 14C radioactity of sugar sheath showed downtrend with the sugarbeet growth, especially it has a significantly downtrend on later period.(4)The 14C radioactity photosynthetic product of sugar sheath is mainly to be in sucrose form,which showed that photosynthetic product is mainly to be in sucrose involved in accumulation and metabolism.(5)The dynamic changes showed different law between all kinds of sugarbeet glucose metabolism key enzyme.