Correlation Study Of Oil Content Between Physiological And Biochemical Indexes And Meteorologicb L Factors In Brassica Napus L.

The physiological and biochemical mechanism of lipid accumulation is the research basic of crop breeding field.The study purpose of rapeseed oil synthesis pathway is to improve oil content. Twelve lines of rapeseed with different oil contents were used to explore the similarities and differences of oil accumulation in the rapeseed development process at Hanzhoung and Yangling.The correlation between physiological and biochemical indexes, geographical meteorological factors and oil content was analysed on the dynamic accumulation of oil content during seed formation of Brassica napus at Hanzhong ang Yangling.The seed of Brassica napus in ultrastructure at different developmental stages of cotyledon inclusion was observed by transmission electron microscope. The results are as follows:Rapeseed oil accumulation was significantly different in different ecological environment,the oil rapid accumulation is 21~42d day after flowering(DAF) at Hanzhong,for 21 days,while at Yangling is 28 ~ 42 d,for 14 days.In the pods during development,oil content,chlorophyll a content,chlorophyll b content,total chlorophyll content of seeds,PEPc activity followed a increase-decrease pattern, reached the minimum values at 49,42,42,42 and 42 day after flowering respectively. Chlorophyll a content,chlorophyll b content,total chlorophyll content of pod skin and the soluble sugar content reached the minimum values at the first sampling(21 day after flowering);the content of chlorophyll a was higher than chlorophyll b;chlorophyll a,chlorophyll b,total chlorophyll content, the soluble sugar content, the soluble protein content and PEPc were correlated with oil content at some stages, but there is no correlation in each stage and has not formed the corresponding distribution of high oil content is the physiological and biochemical indexes of high or low.The chlorophyll and soluble sugar gradually transformed into fat,protein or other substances on rapeseed,the soluble protein and oil content is in a competitive relationship, PEPc activity has a regulatory effect on oil accumulation, but is not the key enzyme of seed oil content.From the results above,we can come to the inference that chlorophyll a content,chlorophyll b content,total chlorophyll,soluble sugar, soluble protein and PEPc aren’t the key factors affecting oil content difference in different regions and lines.Daily minimum temperature, Daily minimum humidity and Daily mean temperature difference were correlated with oil content at Hanzhong. Daily mean temperature,Daily higest temperature and Daily sunshine hours were correlated with oil content at Yangling. Meteorological factors and the accumulation of time play a decisive role in the oil formation process of Brassica napus L.In seed maturation period,the cotyledon cells contain oil body, body protein and starch granule storage materials,also the endoplasmic reticulum, vacuole, mitochondria and chloroplast organelles.Protein bodies formed in vacuoles, oil bodies formed in the endoplasmic reticulum, the starch grains in the chloroplast.In the rapeseed development process, the moisture content decreased continuously, the nucleus dehydrate deformation, organelle disintegration, starch granules increased first and then decreased, the oil bodies and protein content increase in the number of and become transparent, mature seeds were almost filled with oil bodies and protein bodies, some mature cotyledon cells still exist in small starch granules.