Nuclear Changes in the Ageing Ray Parenchyma Cells in Relation to Heartwood Formation

Abstract

Nuclear changes occurring in the ray parenchyma cells of the wood in six tropical taxa have been studied with the aid of standard statistical methods. In the taxa with distinct heartwood (Acacia catechu, Bauhinia tomentosa, Bridelia retusa, Lagerstroemia speciosa), the nuclear area and slenderness ratio show a strong negative correlation with the distance from the cambium except in Lagerstroemia speciosa, where the slenderness ratio shows no relation. In Bauhinia purpurea and Lagerstroemia indica, having no distinct heartwood, the nuclear area and slenderness ratio bear no relation with the distance from the cambium, except for the slenderness ratio in Lagerstroemia indica which shows a positive correlation. The analysis indicates that the change in the nuclear area and slenderness ratio shows a definite pattern during the necrobiosis of the ray parenchyma cells in the taxa where heartwood is distinct.