Effect Of Boron, Molybdenum And Zinc On Yield And Quality And Their Forming Process Of Brassica Napus And Its Mechanism

The field experiment was conducted to study the effects of boron (B), molybdenum (Mo), zinc (Zn) on seed yield and oil quality and their dynamic forming process of Huashuang 4 (Brassica napus). The nutritional mechanism was elementarily studied at the same time. The main results were obtained as follows:1 The results showed that seed yield increased 20.7% under the condition of applying B, Mo and Zn fertilizers comparing to control of B, Mo and Zn deficiency, however, the effect of B and Mo on seed yield was more significant than that of Zn among the three micronutrient fertilizers. What B and Mo deficiency resulted in decrease of seed yield was contributed to significant decrease in the number of seed per silique and siliques per plant. Zn deficiency slightly caused the decrease in seed yield.2 Dry weight of pericarp in main inflorescence and branch increased firstly, and then decreased after flowering. But the seed dry weight increased at all times after flowering. The transportation of nutrition from pericarp to seeds was improved under the condition of applying B, Mo and Zn fertilizers which was blocked when B deficiency.3 Application of boron fertilizer could increase oil content and reduce protein content, but the effect of Zn application was on the contrary. Oil content and protein content increased at the same time when boron and zinc were used together. Mo showed the same function as Zn when added together with Zn, but when together with B it had same action as B. B, Mo and Zn application reduced content of glucosinolate and erucic acid. Effect of them on other fatty acid component was very complex.4 The oil content of seed in main inflorescence increased gradually after flowering and enhanced quickly after flowering for 30-45 days, and then decreased when the silique was 50 days old. For seed in branch, its oil content increased quickly after flowering for 30-40 days, and then kept steady. Oil content was increased under the condition of applying B, Mo and Zn. Protein content of seed in main inflorescence decreased firstly, then increased and keep steady finally. For seed in branch, its protein content increased gradually after flowering. Protein content was increased under the condition of applying Zn fertilizer. Glucosinolate content of seeds in main inflorescence decreased firstly, and then increased. For seed in branch, its glucosinolate content decreased firstly, and then increased and keptdegressive after flowering. The glucosinolate content was decreased under the condition of applying each fertilizer of B, Mo or Zn.5 Oleic acid content of seeds both in main inflorescence and branch increased quickly in early flowering period and kept steady increased after then while the linoleic acid content was on the contrary. Lionlenic acid content decreased firstly then increased and kept steady decreased finally after flowering. Erucic acid content of seed in main inflorescence decreased firstly, and then increased and kept decreased finally. For seed in branch, its erucic acid content gradually decreased after flowering. The 20 acid content of seed both in main inflorescence and branch decreased quickly after flowering for 23-33 days, and then kept increased. Plamic acid content of seeds in main inflorescence increased firstly, and then decreased and kept steady finally. For seed in branch, its plamic acid content kept steady decreased after flowering. Stearic acid content of seed both in main inflorescence and branch decreased firstly, and then kept steady after flowering.6 Chill resistance during winter season and drought resistance in flowering period were decreased under the condition of Mo deficiency, while the chill resistance during winter season was increased under the condition of applying B, Mo and Zn fertilizers. The activity of NR was increased and the utility of nitrogen was advanced when B, Mo and Zn was applied.7 The accumulative content of B, Mo and Zn were increased under the condition of applying B, Mo and Zn fertilizers, while the absorption, transportation and accumulation of B, Mo and Zn were blocked when B, Mo or Zn deficiency. Therefore the quality and quantity were decreased when B, Mo or Zn deficiency.