Evaluation of morphological and anatomical characters for discrimination and verification of some Medicago sativa (L.) Cultivars

摘要

Medicago sativa L. (alfalfa) is one of the most important legume forages in the world. The objective of this study was to characterize and discriminate among 15 alfalfa cultivars with a different geographical origin. Macro-morphological and anatomicalcharacters as well as seed coat sculpture were investigated. Twenty five morphological characters were extracted directly from the fresh specimens. Transverse section in the main stem were carried out; stained and seventeen anatomical characters were examined by light microscope. Seed coat surface was investigated using Scanning Electron Microscope (SEM). Data obtained were coded and analysed using NTsys-Pc software (Version 2.02) and the resulted dendrogram is discussed. The results showed morphological and anatomical variation between the studied taxa. Vascular bundles ranged from 16 to 23. The Egyptian cultivar Nubaria has the lowest number of vessels (16) while the American Super supreme has the larger number (23). The seed coat ornamentation revealed five main surface patterns and suggests the presence of variations in anticlinal boundaries and periclinal walls that provide stable diagnostic characters for morphologically closely related taxa. The dendrogram showed that the Egyptian cultivar Nubaria was the most distant and clustered separately from all the other alfalfa cultivars which were grouped into two main clusters. Seed coat morphology and combination of other plant morphological and anatomical characters permitted identification and discrimination between the examined cultivars. Results obtained in this work could be considered for further breeding strategies and studies.