Weight-length relationships of coniferous wood tracheid skeletons

Cherla Bhaskararama Sastry
The hypothesis is examined that, among individual tracheids of coniferous woods, the weights of holocellulose and alpha-cellulose skeletons are a direct quantitative function of their length, independent of species. A total of 28 annual increments, representing wood from nine coniferous genera and seven families, separated into earlywood and latewood fractions, was delignified with peracetic acid and subsequent reduction with NaBH₄. Further reduction to alpha-cellulose followed for a portion of
more » ... the holocullulose skeletons. About 750 individual holo- and alpha-cellulose tracheid skeletons were measured for length and weight. A specially developed quartz ultra micro-balance, having a weighing range of 0.06 to 14 μg and a precision ± 0.03 μg, was constructed and used to weigh; individual tracheids. Statistical analyses indicated a significant positive curvilinear relationship between length of tracheid and weight of its carbohydrate fraction. Estimated variations accounted for in holocellulose and alpha-cellulose skeleton weights, by the length factor alone were, respectively, 91.9 and 95.7 per cent for pooled data of all the species. No significant differences in holocellulose skeleton weights were evident within species for the same tracheid length, whereas weights of alpha-cellulose skeletons within species, and both the holo- and alpha-cellulose between species, differed significantly. Radial variation for single tracheid weights followed trends similar to those established by others for specific gravity, and percentage of cellulose based on gross wood analyses. Individual tracheids of juvenile wood had significantly lower (1% level) alpha-cellulose skeleton weights than those from mature and overmature wood, while differences were nonsignificant for holocellulose. Overmature wood tracheids were significantly lighter (carbohydrate skeleton weight) than those from mature wood, for the same tracheid length. Differences between earlywood and latewood were explored. For the same tracheid length, both earlywoo [...]
doi:10.14288/1.0075375 fatcat:m6wozjs6rbe7lcmh6slqmfzxiy