Plant Resource Of Allium L. From Xinjiang

The genus Allium L. is the important germplasm resources utilized by people as vegetable, medicinal and ornamental plant in the world. It is mainly distributed in the Northern Hemisphere, especially in Central Asia, Afghanistan, Turkmenistan, Uzbekistan, Iran, Turkey, Mongolia and China, scattered in South of America and Africa. Because of the special geographic location and envirionmemtal conditions, the province of Xinjiang has different species of Allium, and it is becoming the important distribution zone of the genus Allium in China. The present study examined its morphological traits, leaf epidermis, pollen morphology and seed coat of Allium from Xinjiang in order to identify the species, charateristics type, and their taxonomic relationship for better establishing the core collection, analyzing genetic background, and domestication and cultivation of Allium. The results have been summarized as follows:There are 50 species, one variety of Allium from Xinjiang. Basing on the significance taxonomic morphological traits, the key to 68 species of Allium is established. The amount of ovules per locule, bulbiferous tunic, bulb growth habit, leaf shape and cross section traits have subgeneric classification significance. The length ratio of filaments and perianth segments, the trait of inner filaments bases and nectaries have the important taxonomic significance. Leaf size, shape, margin smooth or not, bulblets existing or not, amount of flower, perianth segments colour, ovary shape and style length have the less taxonomic significance, since they are changeable and unstable in different environments, seasons and populations.The leaf epidermis of 43 taxa were examined. The leaf epidermis characteristics has taxonomic value at the species level. Based on the leaf epidermis characteristics, three groups are established. Group 1: leaf epidermal cells are rhomboid, anticlinal walls are straight; Group 2: leaf epidermal cells are rhomboid, anticlinal walls are arched; Group 3: leaf epidermal cells are rectangular, anticlinal walls are straight. Based on these results we propose that rhomboid leaf epidermal cell and arched anticlinal wall are advanced characters, and rectangular leaf epidermal cell and straight anticlinal wall are primitive characters.Pollen morphology of 12 taxa were studied. Pollen morphology has taxonomic value at the species level. Based on the pollen morphology, two groups are established. Group 1: the exine sculpture is striate with perforations; Group 2: the exine sculpture is regulate with perforations. Based on these results we propose that regulate exine are advanced characters, and striate exine are primitive characters. Pollen morphology has limited value in determining taxonomic relationships and setting infrageneric classification.Seed coat sculpture of 38 taxa were investigated. These features has important taxonomic significance in determining taxonomic relationships and setting infrageneric classification. Based on the seed coat sculpture, six groups are exsisted. Group 1: anticlinal walls are arched or arched- straight, cellular arrangement is relatively loose and with reticulated tissue connecting among the basal part of cellulars, more and small verrucate on the periclinal walls; Group 2: anticlinal walls are arched, S type or arched-S, cellular arrangement is relatively close, middle verrucate on the periclinal walls; Group 3: anticlinal walls are straight or straight-arched, cellular arrangement is relatively loose and with reticulated tissue connecting among the basal part of cellulars, irregular lumps and middle verrucate on the periclinal walls; and with reticulated tissue connecting among the basal part of cellulars; Group 4: anticlinal walls are arched or S-arched, cellular arrangement is close, colliculate in cellular center and tuberculate and verrucate on the periclinal walls; Group 5: anticlinal walls are straight-arched, cellular arrangement is close, lumps and verrucate on the periclinal walls;Group 6: anticlinal walls are S type or U type, cellular arrangement is close like islands. Based on these results we propose that S type or U type, close cellular arrangement and big verrucate are advanced characters, loose cellular arrangement, small verrucate are primitive characters, and reticulated tissue are intermediate type.