Genetic analysis on Dolichospermum (Cyanobacteria; sensu Anabaena) populations based on the culture-independent clone libraries revealed the dominant genotypes existing in Lake Taihu, China

An overview of diversity, occurrence, genetics and toxin production of bloom-forming Dolichospermum (Anabaena) species

“…D. mendotae, commonly found in meso to eutrophic lakes, was found to dominate in Lake Iznik, a deep lake of Turkey, on 22 May 2013 with abundance of 4.9 Â 10 7 cell L À1 at WT of 20.6 8C and TN of 1.889 mg L À1 (Akcaalan et al, 2014). Dolichospermum flosaquae was abundant in Taihu Lake, the third largest freshwater lake in China, during the period from late fall to spring, with the peak abundance of 4.0 Â 10 7 cpc gene copies L À1 (based on realtime PCR detection) in April 2009 at a time of TN > 4.0 mg L À1 Liu et al, 2014). A severe cyanobacterial bloom dominated by Dolichospermum circinalis was present in the Barwon-Darling River, Australia, in November and December 1991 with concentrations of around 5.0 Â 10 8 cell L À1 in many localities (Bowling and Baker, 1996), and this bloom was triggered by the combination of many factors incuding lower flow in the river, higher temperatures between 25 and 30 8C, high TP, high TN with low Nox-N and lower TN/TP values of 5-10.…”

“…90). Genotype compositions of natural populations have more widely been studied during Microcystis blooms (Briand et al, 2009;Bozarth et al, 2010;Xu et al, 2011;Zhu et al, 2012), and rarely studied in Dolichospermum blooms (Liu et al, 2014 regression analyses showed that the succession of the two dominant genotypes was significantly correlated with water temperature. These two dominant Dolichospermum genotypes displayed striking seasonal pattern and temperature-associated features, implying that these are major ecotypes during Dolichospermum blooms in Lake Taihu.…”

Photosynthetic characteristics and inferred changes in thylakoid membrane fluidity determine bloom succession between Anabaena and Microcystis in eutrophic lakes

“…The dominant species of blooms often occur with the change of season and specific weather. Bloom succession between Microcystis and Anabaena appears every year in Lake Taihu and Lake Chaohu, which are the major eutrophic lakes in China (Wang et al 2012a;Liu et al 2014). This succession period of dominant bloom species is usually very short and often lasts less than 1 month (Vance 1965;Jia et al 2011).…”

Dominance and succession of Microcystis genotypes and morphotypes in Lake Taihu, a large and shallow freshwater lake in China

“…The most recent studies have consistently shown that warming and nutrient input (both N and P) play interactive roles in the establishment, duration, and severity of blooms (Liu et al, 2014;Paerl et al, 2011;Qin et al, 2010). However, the dynamic characteristics of morphotypes, genotypes, and potential MC-producing Microcystis during bloom development are still not fully understood.…”