Turk J Bot 24 (2000) 227-237 @ T†BÜTAK Research Article Ecological Wood Anatomy of Turkish Rhododendron L. (Ericaceae). Intraspecific Variation Nesime MEREV, HakkÝ YAVUZ Karadeniz Technical University, Faculty of Forestry, Department of Forest Engineering, Trabzon - TURKEY Received: 15.02.1999 Accepted: 25.02.2000 Abstract : The intraspecific relationships of selected wood anatomical characters such as altitude, stem diameter, stem age and average annual ring width were investigated in five different Turkish Rhododendron L. species. Rhododendron luteum Sweet. grows at an altitude of 110 to 2230 m, R. ungernii Trautv. 900 to 2020 m, R. smirnovii Trautv. 1600 to 2230 m, R. caucasicum Pallas 1900 to 3100 m, and R. ponticum L. from sea level to 2230 m in the Eastern Black Sea Region. Although the degree of significance varies between species, correlation and multiple regression analysis indicated a significant correlation between wood anatomical characters and non-anatomical factors. Key Words: Intraspecific variation, wood anatomy, altitude, Rhododendron, Turkey. TŸrkiye Orman GŸllerinin (Rhododendron L.) Ekolojik Odun Anatomisi (Ericaceae). TŸr DŸzeyinde Varyasyonlar …zet : TŸrkiye'deki beß Rhododendron L. tŸrŸnŸn bazÝ anatomik šzellikleri ile rakÝm, gšvde •apÝ, yaß ve ortalama yÝllÝk halka genißliÛi ilißkileri tŸr dŸzeyinde araßtÝrÝlmÝßtÝr. DoÛu Karadeniz Bšlgesi'nde; R. luteum Sweet. 110-2230 m, R. ungernii Trautv. 900-2020 m, R. smirnovii Trautv. 1600-2230 m, R. caucasicum Pallas 1900-3100 m, R. ponticum L. ise deniz seviyesinden 2230 m yŸkseklikler arasÝnda yetißmektedir. Korelasyon ve •oÛul regresyon analizleri sonucunda; tŸrlere gšre šnem dŸzeyleri deÛißmekle birlikte, bazÝ anatomik šzellikler ile anatomik olmayan faktšrler arasÝnda anlamlÝ ilißkiler saptanmÝßtÝr. Anahtar SšzcŸkler: TŸr dŸzeyinde varyasyon, odun anatomisi, rakÝm, Rhododendron, TŸrkiye Introduction and the others are evergreen shrubs. R. caucasicum is According to Metcalfe and Chalk (1) Ericaceae, alpine type, and the others are forest type. particularly Rhododendron L. is widely distributed, but Studies on wood anatomical variation within species species are numerous especially in China and South Africa. are few, and usually did not succeed in finding a Rhododendron species are distributed in China, Tibet, correlation between wood structure and non-anatomical Burma, Nepal, New Guinea, Tropical Asia, Europe and factors (5, 6). A significant correlation was found only in North America. There are about 700 species in these studies carried out in a small region, and showed that regions (2, 3). According to Suzuki (4), the habitats of wood anatomical characters are significantly related with Rhododendron species show a wide range, from low- non-anatomical factors (NAF), especially in relation to the montane forests to alpine regions more than 4000 m altitude (7-9). There are very few studies of intraspecific high. These species are usually shrubs and tall trees about variation compared with interspecific ones in ecological 30 m high and 100 cm in diameter in Nepal. In Turkey, wood anatomy. the ones distributed from sea level to about 3200 m, are The objective of this study was to examine the usually large shrubs (R. ponticum L., R. ungernii Trautv.), intraspecific variation of the wood anatomy of Turkish shrubs (R. smirnovii Trautv., R. luteum Sweet.) or dwarf Rhododendron. shrubs (R. caucasicum Pallas). R. luteum is deciduous, 227 Ecological Wood Anatomy of Turkish Rhododendron L. (Ericaceae). Intraspecific Variation Materials and Methods Artvin-Melo 1900 m, KATO 13395 (nm 38), 1950 m, Wood samples of Rhododendron species were KATO 13396 (nm 37); 2000 m, KATO 13397 (nm 39); collected in the Eastern Black Sea Region (Artvin and the 2050 m, KATO 13398 (nm 199); 2100 m, KATO 13399 FÝrtÝna Valley) at an altitude of sea level up to 3100 m, (nm 190); 2150 m, KATO 13400 (nm 198); 2200 m, with 50 m intervals. The material was sectioned in the KATO 13401 (nm 188), 2230 m, KATO 13402 (nm usual way, and sections were stained with safranin. 117); 2310 m, KATO 13403 (nm 118); Artvin-Atilla Maceration was prepared using Schultze's method (nitric vadisi 2320 m, KATO 13404 (nm 119); 2350 m, KATO acid and potassium chlorate). The length of libriform 13405 (nm 133); 2380 m, KATO 13406 (nm 120); fibres, fibre-tracheids and vessel members, and fibre 2400 m, KATO 13407 (nm 200); 2450 m, KATO 13408 diameters were measured using macerations. The other (nm 121), 2500 m, KATO 13409 (nm 46), 2550 m, quantitative data were measured and counted in sections. KATO 13409 (nm 193), 2600 m, KATO 13410 (nm One sample was studied for a particular altitude at 50 m 194); 2650 m, KATO 13411 (nm 192); 2700m, KATO intervals for 5 species making a total of 176 samples. 13412 (nm 135); 2750 m, KATO 13413 (nm 197); Each average value is based on 50 measurements and 2850 m, KATO 13414 (nm 191), 2950 m, KATO 13415 counts. Results of all individuals are compared in relation (nm 195); Ka•kar- …kŸz yaylasÝ 3000 m, KATO 13416 to different non-anatomical factors (altitude, stem age, (nm 138); 3050 m, KATO 13417 (nm 136); 3100 m, stem diameter, ring width). Correlation among these Kato 13418 (nm 137). R. ponticum; Hemßin-FÝrtÝna four factors and 26 wood anatomical characters are deresi 5 m, KATO 13419 (nm 139); 50 m, KATO 13420 assessed, and anatomical characters are then evaluated by (nm 141); 100 m, KATO 13421 (nm 142); 140 m, multiple regression analysis using non-anatomical factors KATO 13422 (nm 47); 250 m, KATO 13423 (nm 145); as independent variables. The software used is 380 m, KATO 13424 (nm 150); 450 m, KATO 13425 multivariate general linear hypothesis in SPSS on a IBM (nm 151); 490 m, KATO 13426 (nm 153); 550 m, PC. All wood terms used conform to the usage of the KATO 13427 (nm 62); 600 m, KATO 13428 (nm 63); IAWA Committee on Nomenclature (10). 650 m, KATO 13429 (nm 64); 750 m, KATO 13430 (nm 43); 800 m, KATO 13431 (nm 49); 850 m, KATO Voucher number of samples: Rhododendron ungernii; 13432 (nm 66); 900 m, KATO 13433 (nm 67); 980 m, Artvin-Murgul 900 m, KATO 13362 (n. merev KATO 13434 (nm 68); Artvin-Murgul 1000 m, KATO [abbreviated as nm from now on] 184); 950 m, KATO 13435 (nm 4); 1060 m, KATO 13436 (nm 50); 1080 13363 (nm 11); 1000 m, KATO 13364 (nm 186); 1150 m, KATO 13437 (nm 69); 1100 m, KATO 13438 (nm m, KATO 13365 (nm 180); 1200 m, KATO 13366 (nm 41); 1150 m, KATO 13439 (nm 27); 1200 m, KATO 80); 1300 m, KATO 13367 (nm 179); 1350m, KATO 13440 (nm 90); 1250 m, KATO 13441 (nm 91); 1300 13368 (nm 178); 1400 m, KATO 13369 (nm 20); 1450 m, KATO 13442 (nm 101); 1370 m, KATO 13443 (nm m, KATO 13370 (nm 177); 1550 m, KATO 13371 (nm 72); 1450 m, KATO 13444 (nm 74); 1500 m, KATO 174); 1600m, KATO 13372 (nm 172); 1650 m, KATO 13445 (nm 53); 1650 m, KATO 13446 (nm 159); 1700 13373 (nm 98); 1700 m, KATO 13374 (nm 170); 1770 m, KATO 13447 (nm 171); 1730 m, KATO 13448 (nm m, KATO 13375 (nm 85); 1790 m, KATO 13376 (nm 169);1850 m, KATO 13449 (nm 164); 1970 m, KATO 165); 1800 m, KATO 13377 (nm 36); 1900 m, KATO 13450 (nm 107); 2100 m, KATO 13451 (nm 123); 13378 (nm 166); 2000 m, KATO 13379 (nm 110). R. 2230 m, KATO 13452 (nm 113). smirnowii; Artvin-Murgul 1350 m, KATO 13380 (nm 176); 1600 m, KATO 13381 (nm 173); 1620 m, KATO 13382 (nm 163); 1660 m, KATO 13383 (nm 93); 1680 Results m, KATO 13384 (nm 36); 1700 m, KATO 13385 (nm Wood Anatomical Description 83); 1730 m, KATO 13386 (nm 168); 1750 m, KATO 13387 (nm 86); 1770 m, KATO 13388 (nm 84); 1850 Rhododendron: Wood diffuse-porous (11) (Figure 1), m, KATO 13389 (nm 167); 1900 m, KATO 13390 (nm with distinct or indistinct growth rings. Pores evenly 185); 1970 m, KATO 13391 (nm 108); 2020 m, KATO distributed without any tendency to a specific pattern, 13392 (nm 109); 2060 m, KATO 13393 (nm 111); many to numerous (pores/sq. mm), very small to small 2230 m, KATO 13394 (nm 112). R. caucasicum; (tangential diameters); angular, solitary and sometimes in 228 N. MEREV, H. YAVUZ small radial and tangential multiples (2-5 pores) in cross- uniseriate rays composed of upright, square and section. Vessel elements short with thin walls (1-1.25 procumbent cells, wings of multiseriate rays short, of µm), perforation plates mostly scalariform (Figure 5) and square cells), uniseriate rays abundant, 8-17-25 sometimes both simple and scalariform (exclusively in R. rays/mm, average 409 µm height, multiseriate rays few luteum). Spiral thickening present on the walls of the 1-4-11 rays/mm, 2-6 cells wide and 30-78 µm wide, vessel elements but inconspicuous, usually restricted to average 534 µm height (Table 1). ligulate ends. Imperforate tracheary elements R. smirnovii Trautv.: Pores 224-472-960 /sq. mm, intermediate or libriform fibres (few), fibre-tracheids mostly solitary (48-80 %), tangential diameter 11-26-37 (abundant) and vascular tracheids. Libriform fibres with µm, vessel elements 252-490-756 µm long, perforation simple pits (sometimes extremely minute vestige of plates with 10-17-25 bars, intervessel pits opposite to border observed on pits, sometimes inpitted). Fibre- alternate and sometimes sparse. Libriform fibres 497- tracheids with distinctly bordered pits on the radial and 743-1054 µm long, 13-19-24 µm wide, 3-7 µm wall tangential walls. Tracheids, here defined as tracheary thickness. Fibre-tracheids 382-614-886 µm long, 11- elements, resemble narrow vessel elements but lack 17-21 µm wide, 2-5 µm wall thickness. Tracheids perforation or only have a single perforation or very average 459 µm long.