The Study Of Physiological And Biochemical Mechanism On Different Genotypes Brassica Napus L. Under The Heat Stress

21 strains of Brassica napus in the paper were treated under heat stress in the period of formatting seed.Three high-temperature stable strains of Brassica napus and three high-temperature sensitive strains ware selected by comparing the seed oil content,protein content of them,soluble sugar content and grain weight under heat stress.At the same time,the high-temperature steady Brassica napus compared dynamic changes and differences of relevant quality indicators.SPS. SS.PK.PPase.antioxidant activity and chlorophyll content with high-temperature sensitive strains to find the mechanism of lower oil content caused by heat stress.The results were as following: 1 R51.R67 and R69 were selected out as three high-temperature steady strains of Brassica napus; R54.R65 and R64 were selected out as three high-temperature sensitive strains of Brassica napus.2 Soluble sugar content in seed of high-temperature-sensitive Brassica napus strains significantly was decreased under heat stress,and decomposition of soluble sugar was transformed into more protein.This led to lower seed oil in seed of high-temperature sensitive Brassica napus strains. More soluble sugar content was kepted in Seeds of high-temperature stable Brassica napus strains, and decomposition of soluble sugar was normally transformed into oil content.So oil content in seeds of high-temperature steady Brassica napus strains was more stable.3 Oil content was reduced in seed of high-temperature sensitive Brassica napus strains,because the raw materials forming oil was reduced for compound of sugar,transport of sugar and decomposition of sugar significantly affected under heat stress.This normally offered.More oil content was holded in in seed of high-temperature steady Brassica napus strains,because the raw materials forming oil were offered for varieties of sugar,transport of sugar and decomposition of sugar infected relatively small under heat stress.4 Formation of pyruvic acid was interfered.Supply of acetyl CoA about oil synthesize and the formation of three ester triglyceride were affected for PK activity and PPase activity affected on high-temperature sensitive Brassica napus strains by heat stress.PK activity and PPase activity on high-temperature steady Brassica napus strains maintained higher activity.Both Supply of acetyl CoA precursor and formation of three ester triglyceride were not effected,so that it assured oil was normally synthesized.5.SS.SPS.PK and PPase activity on high-temperature sensitive Brassica napus strains were affected by heat stress,but PPase activity most abviously correct with oil compound,so that Heat stress mainly affected PPase activity in seeds of Brassica napus to oil content.6 Epicyte in slique peels of high-temperature sensitive and high-temperature steady Brassica napus strains Brassica napus strains was damaged by heat stress and occurred membrace lipid peroxidize. Epicyte in slique peels of high-temperature-sensitive Brassica napus strains occurred worse membrace lipid peroxidize.7 The water content of the slique peel and the oil synthesize of seeds on high-temperature sensitive Brassica napus were influenced for the solute of its slique peel cells decreased.permeability of cell membranes increased and the normal physiological metabolize was badly influenced under heat stress.The oil synthesize of seeds kept normal for normal physiological metabolize on high-temperature steady Brassica napus under heat stress.8 The oil could be synthesized favorably for the ability increased of elimination O^2-.and H₂O₂.the peroxidization of the cell membranes decreased and the normal physiological metabolize hold out on The high-temperature steady Brassica napus under hear stress.However when,its result in,so,and the normal oil synthesize was influenced for ability of eliminate O^2-and H₂O₂ decreased.the peroxidization of the cell membranes increased and the physiological metabolize turbulenced on the high-temperature sensitive Brassica napus over heat stress,.9,Photosynthesis of the slique peel was influenced on the high-temperature-sensitive Brassica napus when over the high temperature,thereby the oil sythsize was influenced,but the influence to the high-temperature steady Brassica napus was infirmly.10.The high-temperature steady Brassica napus kept strong photosynthetic capacity to increase by improving capacity about eliminating free radical.decreasing membrace lipid peroxidize reaction and increasing osmoregulation level.The high-temperature steady Brassica napus kept normal metabolize function and stable quality index by upper water content and stable enzyme activity level of metabolize...