摘要
水稻化感潜力的田间表现受根际微生物间接调控.以不种水稻的土壤为对照,通过平板计数法、氯仿熏蒸法和BIOLOG分析,探讨了水稻PI312777、IAC47Iguape Cateto和Lemont苗期根际土壤微生物的群落特征及其功能多样性.结果表明,水稻品种显著地影响其根际微生物生物量碳,不同品种水稻根际微生物生物量碳大小为：Iguape Cateto（441.0 mg·kg-1） ＞ IAC47（389.7 mg·kg-1） ＞ PI312777（333.2mg·kg-1） ＞ Lemont（283.8mg·kg-1）,对照土壤为129.3mg·kg-1; PI312777、Iguape Cateto、 IAC47、Lemont土壤的呼吸作用强度依次为1.404、1.019、0.671、0.488 μgC·g-1·h-1, 对照土壤仅为0.304 μgC·g-1·h-1.不同品种水稻根际土壤微生物均以细菌占优势,占微生物总数的58.4%～65.6%,放线菌占32.2%～39.4%,占2.2%～2.8%.BIOLOG分析显示,不同水稻根际土壤的平均颜色变化率（AWCD）显著不同,总以强化感水稻PI312777最高,弱化感水稻Lemont最小,各土壤的AWCD值在培养144 h时均达到最大值,此时PI312777、IAC47、Iguape Cateto和Lemont的AWCD值依次为对照土壤的1.89、1.79、1.60倍和1.43倍.主成分分析表明,从31个因素中提取的与碳源利用相关的主成分1、主成分2和主成分3依次能够解释变量方差的70.08%、11.33%和7.02%;与3个主成分显著正相关的碳源有19种,其中与主成分1显著相关的是酚酸、糖类、氨基酸和胺类,与主成分2显著相关的是酚酸、糖类和脂肪酸类,而与主成分3显著相关的是糖类和羟基酸,对各主成分起分异作用的主要碳源分别是胺类和氨基酸.相关分析表明,土壤微生物总量与细菌数量、莴苣根长抑制率IR、AWCD、MBC、 MBR及Shannon指数间存在显著的正相关;土壤微生物总量与莴苣根长抑制率IR间的显著正相关与水稻品种有关.可见,水稻根际土壤微生物群落、活性和功能多样性与水稻品种密切相关,这些变化可能对水稻田间化感潜力起到重要的调节
Field performance of rice allelopathic potential is indirectly regulated by the microbial flora in rhizosphere. The present study aimed to investigate the population dynamics of microbial flora and their functional diversities in the rhizospheres of rice seedlings of a range of rice varieties with varied allelopathic activity by employing agar plate bioassay, fumigation, as well as BIOLOG analysis. Rice cultivars significantly affected the microbial carbon content in their associated rhizospheres. The contents of microbial carbon were ranked in the decreasing order as cv. Iguape Cateto （441.0 mg·kg^-1） 〉 IAC47 （389.7 mg·kg^-1 ） 〉 PI312777 （333.2 mg·kg^-1） 〉 Lemont （283.8 mg·kg^-1） , with the nil-rice control soil of 129.3 mg·kg^-1. Similarly, the respiration rates of the soils were 1. 404, 1. 019, 0. 671 and 0. 488 p, gC· g^-1·h^-1 for cv. PI312777, Iguape Cateto, IAC47 and Lemont, respectively. The respiration rate was only 0. 304 μC·g^-1·h^-1 for the control soil. The microbial flora in the rhizospheric soils of different rice cultivars was dominated by bacteria （58.4% -- 65.6% ）, followed by actinomycete （32.2% -- 39.4% ） and fungi （ 2.2% -- 2.8% ）. BIOLOG analysis showed that the value of Average Well Color Development （AWCD） differed significantly among rice cultivars. It was always the highest in the rhizospheric soil of the strongly allelopathic rice cv. PI312777, and the lowest in the poorly allelopathic rice cv. Lemont. The AWCD values reached the maximum in all the sampled soils after 144 hours of incubation. The AWCD values from the rhizospheric soils of PI312777, IACA7, Iguape Cateto and Lemont were 1.89, 1.79, 1.60 and 1.43 times higher than that of the control soil. Principal Component Analysis （PCA） identified 3 principal component factors （PCF） in relation to carbon sources, explaining 70.1% , 11.3% and 7.0% of the variation respectively. Nineteen categories of carbon sources were significantly positively related to the 3 principal components
出处
《生态学报》
CAS
CSCD
北大核心
2007年第9期3644-3654,共11页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(30471028
30671220)
福建省科技厅资助项目(2002F012
2005K039)~~
