Studies On Physiological Mechanism Of Sucrose Accumulation In Sugar Beet Root

This study take ty7(high sugar type),ty8(high yield types)and shuangfeng8(standard form) as experimental materials, and it is carried out in test practice base of Northeast Agricultural University on 2008.Starting with the basic substances of sugar accumulation-photosynthetic product ranslocation and distribution, System study on the relationship between the sucrose-metabolizing enzymes and sugar accumulation, beet root sugar accumulation potential and osmotic adjustment of different cultivars , the effect mechanism on beet sugar accumulation of different cultivation measures. That can provide the basic data for sugar beet cultivation physiology, theoretical basis for the sugar beet high-yield and high-sugar physiological selection and scientific regulation.The result shows that:(1)In the different period of sugar beet growth and development, comparison the 14C specific radioactivity of the leaf and the petiole and the root, and shows this laws as follows: leaf > Petiole>root. The photosynthetic product in leaf translocation to the root followed concentration gradient. It has a strong photosynthesis ability in sugar content accumulated stage, But the transportation function of photosynthetic product decreased significantly, The 14C photosynthetic product specific radioactivity in leaf is still large.(2)Sugar accumulation in beet is the result of common regulation of sucrose phosphate synthase and sucrose synthase and neutral invertase acid invertase and Mg2+-ATPase,there is close contact between sucrose-metabolizing enzymes and the content of sucrose-metabolizing main product.(3)Mg2+-ATPase activity and sugar content shows reduced in different degree in root and leaf of different cultivars after DNP,NO3- treatment.(4)Determination the sugar content of beet root vitro body wafer after 2h,4h and 6h treatment in sucrose solution. It find that the order of beet accumulation sucrose potential in different period as follows : Leafage formation stage>root epacme>sugar content accumulated stage It has no obvious difference that the sugar content change of ty7 and ty8 in seedling stage, and the difference is significant in root epacme and sugar content accumulated stage, high-sugar type cultivars is significantly higher than high-yield type. Sugar accumulation potential is related to genotype,accumulation intensity is related to growing process.(5)That take 800mmol/Lmannitol as osmotic adjustment substance, Sugar uptake of beet root tissue wafer is decreased, This shows that involved in the regulation of vector and regulate the permeability of plasmodesmata ,which can effect sugar transportation and accumulation(6)It has great effect on sugar beet yield and sugar content by pick 10 or 20 leaves per 10 days. The yield by treatment is reduced 15.28% and 18.42% than that of no picking. The lowered range of sugar content is increased with the picking leaves number, it is reduced 0.4 degree and 1.5 degree than that of no picking.(7)The yield and sugar content is lower than the check (N120) when no nitrogen application; The yield is increased 9.8% than the check, while sugar content is lower than the check after N180 teatment It goes against the improvement of sugar yield that excess amount of nitrogenor less amount of nitrogen.