凹叶厚朴粗壮枝和细弱枝的树皮和韧皮部结构的比较研究

凹叶厚朴的树皮由外向内为周皮、皮层、初生韧皮部的纤维束和次生韧皮部.筛管分子具有复筛板或单筛板、P-蛋白质,筛板孔开放,可见联络索,无淀粉粒.伴胞为与筛管分子等长的一列或单个细胞.粗壮枝周皮的木栓层约6层细胞组成,皮层中油细胞、淀粉粒、石细胞较多.细弱枝周皮的木栓层约3层细胞组成,皮层中油细胞、淀粉粒、石细胞较少.粗壮枝和细弱枝筛管分子宽度相当,但前者筛管分子较长,筛管蛋白质较多,后者筛管分子较短,筛管蛋白质较少.

Comparative anatomical studies of bark and phloem of stout branch and leptos branch in Magnolia biloba

The bark structure of Magnolia biloba, from external to internal parts, includes periderm, cortex, fibre bundies of primary phloem and secondary phloem. Its sieve tube members have P-protein, compound or simple sieve plates, but no starch grains. The pores of these sieve plates are opening, so connecting strand can usually be seen. Companion cells arrange in a row or single cell as long as the sieve tube member. There are about six layer cells in cork of periderm, more oil cells, starch grain cells and sclereid in cortex in stout branches, where as three layer cells, less oil cells, starch grain cells and sclereid in cortex in leptos branches. The width of sieve tube members in stout branches is equal to that in leptos branches, but more length of sieve tube members and more P-protein than that in leptos branches.