Study On Relationship Between Source And Sink After Flowering In Oilseed Rape

Through analyzing the proportion of photosynthetic area, seed number per pod, seed volume and seed weight etc. in different pod size, planting densities and varieties and N fertilizer application to study the relationship between the source and sink after flowering in oilseed rape. The main.results were as follows:1. Pod area of oilseed rape attributed high efficient photosynthetic area. The proportion of pod area in total photosynthetic area increased as the single pod area increasing, and decreased a little as the increasing of planting density and N fertilizer application.2. Seed number per pod of oilseed rape decreased as the increasing of planting density, increased first and then decreased as the increasing of pod length or area, and was affected very little under different N fertilizer application. Single seed volume and total seed volume per pod increased first and then decreased as the increasing of planting density, and was positively correlated with pod length or area significantly.3. SNPA (seed number per pod area) and SVPA (seed volume per pod area) were the important indices to measure relative sink capacity after flowering in oilseed rape. Both of them were parabolic curve function with planting density and accorded exponential function with different pod length or areasignificantly. SNPA decreased a little as the increasing of N fertilizer application.4. Through testing characters of seed on the different parts of plant, the results indicated that seed weight was positively correlated with seed volume significantly. Path analysis also indicated that the increasing of seed volume was the main reason to increase seed weight. Measures of adjusting planting density and selecting varieties etc. to increase seed weight were also through the increasing of seed volume.5. SWPV (seed weight per seed volume) decreased as the increasing of seed volume in same plant, increased as the increasing of seed volume in different planting densities, and was correlated with seed volume insignificantly in different pod length or area.6. PPA (the productivity per pod area) was positively correlated with SNPA and SVPA significantly. The results from Path analysis showed that the SVPA was the main reason to increase PPA. Measures of adjusting planting density, increasing N fertilizer application and selecting varieties etc. to increase PPA were also through the increasing of SVPA or SNPA.7. Promoting the growing of pod and increasing seed number and seed volume per pod area could increase not only the proportion of high efficient photosynthetic area in population but also the photosynthetic efficiency of pod.