Study of morphology,reproduction and chromosomes of three Bangia atropurpurea(Bangiales,Rhodophyta)populations

Bangia atropurpurea has been inadequately studied in China.To understand the basic biological characteristics of B.atropurpurea in China, the morphology, reproduction, chromosome characteristics and pigment contents of B.atropurpurea were studied in this research.Three B.atropurpurea samples were collected from Niangziguan(Shanxi Province), Wuquanshan(Gansu Province)and Xinglongshan(Gansu Province).The growth environment conditions of the Bangia samples were studied in the fields.The morphological and reproduction characteristics of these three samples were examined under the light microscope.The nuclear division processes of samples were observed under a photomicroscope with an aceto-iron-haematoxylin-chloral hydrate stain.The freshwater Bangia populations in these three different locations were found adhered to rocks, waterfall and fast flowing streams, and the Bangia populations were often found to coexist with Cladophora insignis.These Bangia samples were unbranched filaments and the length ranged from 1.1 cm to 3.5 cm.Phycobiliprotein contents of three samples were ranged from 7.26 to 9.46 mg/g, in which the sample from Niangziguan contained the highest concentration, followed by the sample from Wuquanshan.The Xinlongshan sample contained the lowest phycobiliprotein contents concentration in comparison with other samples.These Bangia samples reproduced asexually and the released archeospores germinated into gametophytes continously.The nuclear division of three Bangia samples were mitosis and the sister chromosomes always assembled as a "8" or a "X" shape in the early metaphase.All freshwater samples had the consistent somatic chromosome numbers of n=4.The length of chromosomes were ranged from 0.42 to 1.67 μm and one of the chromosomes was usually found to be shorter than the other three.This is the first time that the biology characteristics of Bangia samples from Wuquanshan and Xinglongshan have been systematically studied in China.That provides useful information for the B.atropurpurea research.