Boron Distribution in Cell Wall Components in Rape Cultivars (Brassica napus) with Different Boron Use Efficiency Study on the influence of B on cell wall components in different B efficiency rape cultivars Effects of boron-calcium nutrition on suspension-cell of rape cultivars with different boron efficiency Response of rape cultivars with different boron efficiency to boron-magnesium nutrition at seedling stage Differences in mineral nutrients content in xylem and phloem sap between cotton cultivars with different boron efficiency Study on the allelism of boron efficiency genes in Brassica napus Construction of a Brassica napus Bacterial Artificial Chromosome Library and Identification of Clones Linked to Boron Efficiency Gene