Variation Analysis In Tracheid Morphological And Basic Density Of Loblolly Pine Provenances Grown In Fujian

Loblolly pine (native to US) was one of the most successful exotic species in China for wood industrial materials. There was obvious relationship between wood traits and cultivated environment, but this kind relationship was uncertain. Geographical provenances would present some obvious variations grown in new location, so it is necessary to do some research about the wood properties variation rules of the trees grown in new location. It is significant that in understanding the rules of loblolly pine provenances geographical variation. This will provide guidance in choice of high compatibility provenances and programming seed areas even in oriented cultivation. This study did lots of work about the variation of tracheid morphological features, width of growth ring and basic density. It also studied about the mutuality between the factors mentioned above and the geographical and meteorological factors. All the loblolly pine increment cores studied in this research were collected from Nanyu state plantations located in Fujian, China and US Forest Service provided the seeds of the samples. The research will provide the scientific basis for the choice of fast-growing, high quality loblolly pine provenances and rational use of the timber resources.The variance analysis indicated there was a great difference in the growth ring width among provenances. The difference was significant at the level of 0.01. The difference achieves 51.72% in ring width between the provenances of largest and the smallest. At radial direction growth ring width increased more rapidly for the 1-5 growth rings, decreased for the 6-9 growth rings, then increased approaching phloem.In the original of growth, the variance analysis indicated there were significant differences in tracheid morphological features including tracheid length, tracheid width, tracheid diameter, tracheid double wall thickness, tracheid length-width ratio, tracheid wall thickness-diameter ratio and tracheid diameter- width ratio. Results showed by multiple comparisons that there were not significant differences between each two provenances, but part of provenances. The grade of canopy density would rise with the increasing in the age and crown of the trees, it would induce reducing in diversity of tracheid morphological features at the latter of the growth period. In the entire period of growth, the variances were distinct in the weighted morphological features of tracheid length, tracheid double wall thickness and tracheid length-width ratio. And the variances of other features were indistinctive.The coefficient of variation showed that individual trees within each of these provenances were greater than the variability among provenances in the tracheid morphological features of spring wood, autumn wood and weighted wood among each growth ring. In addition, the environment also played an important part in the variation of tracheid morphological features by analyzing F value of the block.It showed the increasing tendency basically for the radial direction of various provenances in tracheid morphological features value. The tracheid length, tracheid double wall thickness, tracheid length-width ratio and tracheid wall thickness-diameter ratio of autumn wood were significantly higher than the corresponding characters of spring wood. The mean tracheid length of 5 segments growth ring of 31 loblolly pine provenances were 2015μm,2826μm,3024μm,3144μm,3522μm. The tracheid double wall thickness were 7.28μm,9.30μm,9.37μm,14.33μm,14.35μm. The tracheid length-width ratio were 50.98,64.11,68.1,70.09,76.45. And the tracheid wall thickness-diameter ratio were 0.228,0.277,0.666,0.488,0.466 followed.Trend was increasing of loblolly pine basic density from the pith out to 14 round year by year. The variations were significant in the basic density of provenance. 1-3 round, 1-5 round, 1-7 round, 1-9 round, 1-14 round provenance average values were 0.346g/cn~3,0.364 g/cm~3,0.388 g/cm~3,0.403 g/cm~3,0.419 g/cm~3 in turn. Provenance F value were 1.70,1.74,2.37,3.11,3.37 respective The variation of basic density was influenced by genetic, but also subject to site environmental conditions as the same as the tracheid morphological features.There was some geographic variation model in the tracheid morphological features. There was positive correlation between latitude and tracheid wall thickness-diameter ratio, and negative correlation between latitude and other tracheid morphological features. Longitude and tracheid diameter- width ratio was negatively correlation, and longitude with other characteristics was positive correlation. There were not significant correlation between loblolly pine basic density and geographical factors. And it also was no apparent pattern of variation with longitude and latitude.