Study On The Cytology And Flora Component Of Brassicaceae In Xinjiang

The Brassicaceae are one of the most valuable of economic crop in angiosperm. Brassica and Raphanus are the main vegetable or oil plants in north. There are also many purposes including condiment of mordacity, medicine, ornamental and coloring matter in other genera of Brassicaceae.Brassicaceae is a big natural and world family, and have many same characters of morphological, such as containing mustard oils, cruciform corolla, tetradynamous stamens, silique fruit and so on. So it is easy to identify from other taxa. But it has some problems of classification, especially in identification of some tribe or genus. This paper studies the cytology and flora of Brassicaceae in Xinjiang to find some evidences of classification of Brassicaceae. The main results are as follows:1. Cytology: we are studied 27 materials, and analysis karyotype of 11 materials of them. The karyotype formula: Cithareloma vernum Bunge 2n=2x=12=6m +6sm, Neotorularia korolkovi (Regel. Et Schmalh)O.E. Schulz 2n=2x=14=12m+2M, Berteroa incana (Linn)DC. 2n=2x=16=12m+4sm, Leispora exscapa (C.A. Meyer)Dvorak 2n=2x=14=4m+10sm,Tetracme quadricornis (Steph.)Bunge 2n=2x= 14 =8m+6sm, Smelowskia calycina ( Steph. ) C.A.Mey. 2n=2x=12=8m+4sm,Oreoloma violaceum Botschantzev 2n=4x=28=18m+10sm, Isatis indigotica Linn. 2n=2x= 22= 12m+10sm, Lachnoloma lehmannii Bunge, 2n=2x=14=6m+4sm+4st, Erysimum siliculosum(Marsch.von Beiberst)DC. 2n=2x=14=12m +2sm, Dontostemon elegans Maxim 2n=2x=14=6m+8sm. The most evolutional karyotype is Dontostemon elegans. Only 4 materials have polyploid, they are Oreoloma violaceum, Malcolmia africana, M. scorpioides, Alyssum desertorum. Rest of them are all diploid. The basic numbers of chromosome of all the species are diversiform. The basic numbers are 6,7,8,10,11.2. Study on Tauscheria: we study the characters morphology, micro-morphology, and cytology of Tauscheria. We suggest that Tauscheria gymnocarpa should be an independent species, resume previously systematic status.3. Analysis the flora: Brassicaceae have 76 genera, about 180 species in Xinjiang, the genus occupy 73.08% and species occupy 45% of the country. They distribute from plain to Alp Mountain. So we deduce that Xinjiang is the center of distribution of Brassicaceae, and perhaps the center of evolvement. Many of them are ephemeral plants in the north of Xinjiang, which are important part of flora of the early spring-plant. They play a very important role in protecting frail ecosystem, and supplying feed for livestock.