青藏高原东部几种自然土壤放线菌的生态分布

ECOLOGICAL DISTRIBUTION OF SOIL ACTINOMYCETES IN EASTERN PART OF THE QINGHAI TIBET PLATEAU

采用常规方法研究了青藏高原东部几种自然土壤中放线菌区系及与土壤养分的关系 .结果表明 :①供试土壤有机质、全氮、速效氮、速效钾及速效磷含量变异很大 ,其变异系数分别为 71.9% ,6 0 .8% ,6 5 .8% ,5 3.5 %及 130 .6 % .pH差异很小 ,平均值为 8.16 ,变异系数为 6 .5 % .②供试土壤放线菌数量n(cfu) =(8.2～ 14 72 .7)× 10 4g-1.放线菌组成以链霉菌为主 ,其次为小单孢菌 ,二者分别占土壤放线菌总数的 4 1.7%～ 90 .9%及 0～ 5 3.6 % ,其平均值和变异系数分别为 82 .2 %和 18.0 %及 10 .3%和 15 4 .2 % .沼泽土中小单孢菌占放线菌总数的 5 3.6 % ,盐化土中无小单孢菌 .高山草甸土、森林棕褐土、黑钙土及灰钙土中分别出现链孢囊菌属与马杜拉菌属、间孢囊菌属、诺卡氏菌属及链孢囊菌属 .③在链霉菌属中 ,可划分 10个类群 ,其中白孢类群、灰褐类群、金色类群、粉红孢类群为优势类群 ,分别占链霉菌总数的 2 3.3%～ 5 7.0 % ,2 .7%～ 32 .8% ,5 .8%～ 6 3.7及 2 .3%～ 2 4 .6 % ,其次为淡紫灰类群和灰红紫类群 ,6个类群共占链霉菌总数的 70 .3%～ 10 0 % .盐化土和黑钙土分别为链霉菌数量与类群最少和最多的土壤生态体系 .④供试土壤按植被、土壤形成条件及土壤性质分为高山草甸土、森林棕褐土、黑钙土、?

Actinomycete population and their relations to soil nutrients were studied by normal methods in several natural soil samples collected from the eastern part of the Qinghai Tibet Plateau. The results indicated that: ① The organic matters, total nitrogen, available nitrogen, available potassium and available phosphorus contents of the tested soil samples varied obviously, and their coefficients of variation were 71.9%,60.8%,65.8%,53.5% and 130.6% respectively.The pH value of the tested soil samples varied slightly, of which the mean was 8.16 and the coefficient of variation was 6.5%. ② The quantities of actinomycete in the tested soil samples were n (cfu)=(8.2～1 472.7)×10 4 g -1 . Streptomyces was the main genus, followed by Micromonospora . Their percentages of the totals were 41.7～90.9 (the mean was 82.2,and the coefficient of variation was 18.0%) and 0～53.6 (the mean was 10.3, and the coefficient of variation was 154.2%), respectively. The Micromonospora 's percentage was 53.6 in marshy soil sample, and there was no Micromonospora in saline soil sample. Streptosporangium and Actinomadura could be found in alpine meadow soil, and Intrasporangium in sylvogenic soil, Nocardia in chernozem and Streptosporangium in sierozem. ③ Streptomyces could be classified into 10 groups. Albacores, Griseofuscus, Aureus and Roseosporus were dominant groups, and their percentages of the Streptomyces were 23.3～57.0,2.7～32.8,5.8～63.7 and 2.3～24.6, respectively, and Lavendulae and Griseorubro violaceus were followed. These 6 kinds were 70.3～100 percent of the total Streptomyces . Saline soil was the ecological system where the quantity and the kinds of Streptomyces were the least, and Chernozem was just opposite. ④ According to plants, soil farming conditions and soil quality, the tested soil samples could be classified into 8 ecological types: alpine meadow soil, sylvogenic soil, chernozem, sierozem, castanozem,saline soil, eolian sand soil and marshy soil. The biological varieties of actinomycete in saline soil, eolian sand soil and marshy soil were worse than those in other soils. Tab 5, Ref 16