Study On Mechanisms In Boron Efficiency Differences Between Different Boron Efficiency Rape Cultivars By Grafting Methods

The different response to boron deficiency and their mechanism in rapeseed(Brassica napus L.) cultivars with different boron efficiency was studied under soiland solution culture condition by grafting them each other. Main results are as follows:1. By comparing different grafting methods, sprout insertion was proper graftingmethod because of the highest survival rate and fastest grafting speed.2. It is the key to improving survival rate to manage after grafting, especiallysuitable temperature(20℃-30℃) and humidity(90%-95%). The death phenomenonappeared in the 4th day to the 9th day; and in the 10th to 12th day could find out whethergrafting plants could survive. Agronomic characters of grafted plants were similar withtheir maternal plants.3. Agronomic characters of grafted oilseed rape plants were similar with theirmaternal plants when boron deficiency was serious, and their yields were mainly affectedby the shoots, but the affect of root was not excluded. Their yields were affected by theshoots and the roots at gentle boron deficiency.4. Soil and solution culture test results indicated that boron deficiency significantlydecreased the boron content in the shoots, roots and bottom leaves in grafted ornon-grafted oilseed rape plants, but the decrease degree in the boron-efficient oilseed rapecultivar was the least, that of the boron-inefficient one was the most, and their plantsgrafted each other was in the middle of them. The effects of boron deficiency on boronaccumulation in shoots in all oilseed rape plants were similar to their boron content.Furthermore, there was a tendency that the boron distribution rate in the shoots ofboron-efficient cultivar and the plant grafted onto the boron-efficient rootstock was higherthan that of boron-inefficient one and the plant grafted onto the boron-inefficientrootstock, respectively, whether boron supply was sufficient or deficient. It was suggestedthat the oilseed rape boron efficiency might be a cooperative consequence of boronabsorption and transportation from roots to shoots.5. B, N, P, Ca, Zn contents of bottom leaves in grafted or non-grafted oilseed rapeplants were mainly affected by shoots of the plants, K, Mg were mainly affected by roots,and Cu, Fe, Mn might be affected by the two parts of the plants.