Effect Of Several Enzymes' Activity On Oil Content And Fatty Acid Compositions In Rapeseeds (Brassica Napus)

High oil content has been one of the new quality targets following double-lowquality in 1980s. Many studies have been made on raising oil content, includingbreeding, cultivation, ecological and genetic engineering techniques etc, but studieson physiological and biochemical basis of raising oil content was lacked and notcomprehensive. This paper mainly discussed the key factors for raising oil contentfrom physiological and biochemical aspects.The results were described as following:1. Two genotypes of Rape with high and low oil content which has same geneticbackground was used as materials in this experiment, and the flowers blooming at thesame day were Marked for analysis.2. The following physiological and biochemical factors was measured during seed'sformation in the two genotypes of Rape: oil content, fatty acid compositions,G6PDHactivity, PPase activity, ACCase activity, soluble sugar content, starch content,sucrose content, protein content, chlorophyll content. The dynamic changes of thesefactors and their difference between two genotypes during seed's formation have beenanalysised in this paper.3. The main conclutions were abtained as following. In the stage of oil content risingfastest, G6PDH activity and PPase activity also rise fastest, and soluble sugar, starch,sucrose content decline rapidly; Chlorophyll and protein content shows same dynamicchange with oil content; Oleic acid content in seed has two peak curves whichincreases quickly after flowering and fertilization and stagnates.within 31-38 d andcontinues increasing after 38d; Linoleic acid content shows highest in the initial, butdeclines with the subsequent development of the seeds; The change amplitude ofpalmitic acid, stearic acid and linolenic acid is small; In the course of seedformation, especially stage of oil content rising fastest, G6PDH activity,PPaseactivity,chlorophyll content and oleic acid content of high oil content genotype ishigher than low oil content genotype, but linoleic acid on the contrary; The differencebetween high and low oil content genotypes in oil content, oleic acid content, linoleic acid content,G6PDH activity, PPase activity, ACCase activity, soluble sugar content,starch content, sucrose content, protein content, chlorophyll content reachessignificant level or very significant level; The G6PDH activity and PPase activity wassignificantly correlated with oil content, so they are key factors that impacting oilcontent; other factors have relevance with oil content, but the correlation coefficientsdon't reach significant level; Correlation between Oleic acid content and oil content issignificantly positive, and correlation between linoleic acid content and oil content issignificantly negative.