[Diversity and resistance of rhizobia isolated from Caragana intermedia in Maowusu sandland].
Fifteen rhizobia strains were isolated from wild shrubby legume Caragana intermedia in Maowusu sandland. A dendrogram was constructed based on esterase profiles, showing a rich diversity of these rhizobia. Many biochemical characteristics were detected, including acid or alkali production, catalase activity, utilization of sole carbon sources, and resistance to salt, acid-alkali and temperature variation. The results indicated that all the rhizobia strains isolated from Caragana intermedia could excrete H+ on YMA agar and produce catalase. 73.3% strains could tolerate NaCl stress at 3% concentration, and 80% strains could grow at 50 degrees C. Except the difference in lactose and starch utilization, rhizobia strains had no bias on the rest carbon sources. However, the difference in resistance to stress existed among strains, which might be related to the adaptation of rhizobia to diverse landscapes in Maowusu sandland. It was revealed that rhizobia nodulating Caragana intermedia could be used as a new germplasm to fix nitrogen under severe environment.
Gao
Lifeng
L
Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. gao_lifeng@yahoo.com.cn
Deng
Xin
X
Wang
Hongxin
H
Hu
Zhiang
Z
D032602:Caragana / Q000382:microbiology*; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D012231:Rhizobium / Q000302:isolation & purification*; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature
D003470:Culture Media; D012965:Sodium Chloride