Komparativna morfo-anatomska analiza roda Trifolium L. 1737. (Fabales, Fabaceae)

Abstract

<p>U radu je izvr&scaron;ena komparativna analiza kvalitativnih i kvantitativnih anatomskih karakteristika vegetativnih i reproduktivnih organa 20 vrsta roda Trifolium L. Ispitana je varijabilnost pojedinih karaktera i izdvojeni su oni koji imaju taksonomski značaj i mogu biti od koristi za diskriminaciju vrsta i sekcija. Izdvojene su histolo&scaron;ke karakteristike biljnih organa koje su od značaja za kvalitet biljaka koje se koriste za ishranu životinja i koje mogu biti kori&scaron;ćene u oplemenjivanju gajenih vrsta i pobolj&scaron;anju njihove hranljive vrednosti i svarljivosti. Procenjen je potencijal divljih vrsta za njihovo eventualno kori&scaron;ćenje kao stočne hrane. Stereolo&scaron;kom metodom određena je volumenska gustina pojedinih tkiva lista kod odabranih vrsta i procenjen značaj tih parametara za određivanje kvaliteta detelina kao stočne hrane.<br />Kombinacija odabranih anatomskih kvantitativnih i kvalitativnih karaktera vi&scaron;e biljnih organa ima značaja u taksonomiji, na nivou razdvajanja sekcija. U anatomskom pogledu vrste sekcije Chronosemium su međusobno najsličnije i jasno se na osnovu anatomskih karakteristika izdvajaju od vrsta ostalih sekcija. Karakteri&scaron;e ih odsustvo papila na epidermisu lista, prisustvo i specifičan, okrugao oblik protuberanci na nežlezdanim trihomama lista, tri provodna snopića u lisnoj dr&scaron;ci, pet provodnih snopića u cevi ča&scaron;ice, odsustvo trihoma na spolja&scaron;njem epidermisu cevi ča&scaron;ice i visoko procentualno uče&scaron;će epidermisa u građi dr&scaron;ke cvasti. Vrste sekcije Trifolium imaju relativno gust indumentum na spolja&scaron;njem epidermisu cevi ča&scaron;ice, abaksijalnom epidermisu zalistaka i oba epidermisa lista, na vrhu u&scaron;iljene provodnih snopića u cevi ča&scaron;ice. Vrste sekcije Lotoidea su znatno heterogenije i njihove zajedničke osobine su odsustvo protuberanci na nežlezdanim trihomama lista, rebrast oblik poprečnog preseka dr&scaron;ke cvasti i prisustvo malog broja trihoma na spolja&scaron;njem epidermisu cevi ča&scaron;ice. Vrstu T. subterraneum iz sekcije Trichocephalum moguće je sa sigurno&scaron;ću determinisati na osnovu karaktera ča&scaron;ice i semena.<br />Vrste koje se koriste za ishranu životinja imaju nizak sadržaj vlakana, naročito u listovima, odnosno relativno nisko uče&scaron;će debelozidnih, a visoko uče&scaron;će tankozidnih ćelija u strukturi biljnih organa. Po ovim karakterima, gajenim vrstama su veoma slične vrste T. angulatum, T. medium i T. pannonicum, pa se može smatrati da one poseduju određeni potencijal i kao krmne biljke.<br />Modifikacijom i prilagođavanjem stereolo&scaron;ke metode za ispitivanje strukture tročlano složenih listova pro&scaron;irena je mogućnost primene ove metode u botanici. Stereolo&scaron;kom analizom je utvrđeno da listovi gajenih biljaka imaju manju volumensku gustinu provodnog i mehaničkog tkiva, a veću mezofila, u poređenju sa listovima biljaka koje se ne koriste kao stočna hrana. Komparacija rezultata dobijenih klasičnom histolo&scaron;kom analizom i stereolo&scaron;kom analizom pokazuje da primena obe metode dovodi do istih zaključaka kada su u pitanju kompaktna tkiva (epidermis, provodno i mehaničko tkivo). Stereolo&scaron;ku metodu smatramo preciznijom kada se analizira rastresito tkivo mezofila, jer procentualno uče&scaron;će intercelulara nije moguće odrediti standardnim anatomskim ispitivanjima.</p>

<p>Comparative analysis of qualitative and quantitative anatomical characteristics of vegetative and reproductive organs of 20 Trifolium L. species was carried out. Variability of characters was examined and those of taxonomic significance, for determination of species and sections, were pointed out. Histological characteristics of plant organs, that determine the quality of forage crops and that could be used in breeding of cultivated species and improvement of their nutritive value and digestibility, were also examined. The potential of wild growing species for their possible use as forage crops was evaluated. Leaf tissues volume density of selected species was determined using stereological method, and significance of those parameters in determination of quality of clovers as forage crops, was evaluated.<br />Combination of selected anatomical qualitative and quantitative characters of plant organs has significance in taxonomy, at the level of separation of sections. From anatomical point of view, species of the section Chronosemium are the most similar to each other and clearly separated from the species that belong to other sections. They are characterized by the absence of papillae on leaf epidermis, presence of protuberances of specific, rounded shape on leaf non-glandular trichomes, three vascular bundles in petiole, five vascular bundles in calyx tube, absence of thichomes on outer epidermis of calyx tube and high percentage of epidermis in peduncle. Species of the section Trifolium have relatively dense indumentum on leaf epidermis, outer epidermis of calyx tube and abaxial epidermis of stipulae, protuberances with sharp tips on non-glandular trichomes, crystals in stipulae mesophyll and ten or more vascular bundles in calyx tube. Species of the section Lotoidea are more heterogeneous and their common characteristics are absence of protuberances on leaf non-glandular trichomes, ribbed cross section of peduncle and small number of trichomes on outer epidermis of calyx tube. Species T. subterraneum, that belongs to section Trichocephalum, can be easily determined on the basis of calyx and seed characters.<br />Species that are used as forage crops have low fiber content, especially in their leaves, with relatively low percentage of thick-walled and high percentage of thin-walled cells in their organs. On the basis of those characters, species T. angulatum, T. medium and T. pannonicum are very similar to cultivated ones, and could be considered as species that possess certain potential to be used as forage crops.<br />Modification and adjustment of stereological method for examination of the structure of compound trifoliate leaf enables wider application of this method in botany. The results of stereological analysis show that leaves of cultivated species have lower volume density of vascular and mechanical tissue and higher of mesophyll, compared to the leaves of the plants that are not used as forages. Comparation of the results obtained by classic histological and stereological analysis shows that application of both methods leads to the same conclusions for compact tissues (epidermis, vascular and mechanical tissue). Stereological method is more precise for the analysis of loosely mesophyll tissue, because it is not possible to evaluate percentage of intercelulars using standard anatomical examinations.</p>