Vascular bundles in lower secondary branches of hybrid rice Liangyoupeijiu devel oped poorer than those in upper primary branches.The conduit, sieve tube and ac company well in lower secondary branches are not cell differentiated,and the to tal areas of its conduit and phloem and single areas of conduit, sieve tube and accompany cell become smaller than those in upper primary branches. The content of soluble sugar of lower secondary branches is higher than that of upper primar y branches in mature period, the obstruction of carbohydrate and other materials transportation bigger, as is one of t...
