9株绵羊肺炎支原体内蒙古分离株P113基因克隆及蛋白序列分析

[目的]克隆绵羊肺炎支原体内蒙古分离株P113基因,比对、分析不同菌株P113蛋白序列,为研究绵羊肺炎支原体P113蛋白的生物学功能提供参考。[方法]设计绵羊肺炎支原体P113基因特异性引物,采用PCR方法扩增9株绵羊肺炎支原体内蒙古分离株的P113基因片段;对获得的9株绵羊肺炎支原体P113基因片段进行测序分析,将DNA序列翻译为氨基酸序列,对不同菌株的P113氨基酸序列进行比对。[结果]不同分离株P113基因片段扩增产物大小不同。氨基酸序列分析显示,C末端序列重复区域长度存在差异,以KKAEGA（S）QNQG为主要重复序列单元。不同菌株重复序列单元数量不同,NM01-MO株和CK-MO株的重复序列单元数量最多,为16个;LK-MO株重复序列单元数量最少,为3个;多数菌株之间重复序列单元数量差异较大。[结论]绵羊肺炎支原体内蒙古分离株P113氨基酸序列的C末端重复序列单元数量不同,这些不同数量的重复序列影响P113蛋白结构,进而可能影响其生物学功能。     

红藤苗木施肥量的初步研究*

红藤(Daemonorops margaritae Hance)是我国主要商品藤种之一,目前已在广东、海南和福建等省推广人工栽培。红藤苗木培育周期长,从播种到成苗出圃约需一年时间,而壮苗技术是推广人工栽培的关键。为了研究红藤壮苗培育技术,在取得藤苗光照试验和矿质营养试验结果的基础上,安排了苗木施肥试验,以探求红藤苗木最适施肥量,为合理施肥提供科学依据。     

桤柏混交林的效益探讨

桤柏混交林是川中丘陵区的主要造林类型。本文对不同年龄阶段的桤柏混交林进行了对比研究。结果表明：２６年生的混交林中其柏木在单位面积上的蓄积最比纯柏木林大８０．６％，地上中分生物量比纯林高４７．２％；混交林柏木的Ｎ，Ｐ，Ｋ，Ｃａ等营养元素含量分别 比纯柏林高６５．４７％，５０．４３％，７．７０％和１７．９６％；混交林内空气相对湿度比纯柏木林大９．４－１０．５％，混交林能改善生态环境，提高土壤肥力。     

Comparative analyses on the litter in Korean pine Mongolian Scots pine and Dahurian Larch plantations

Comparative analyses were conducted on the nutrient element content and returning amount of main fractional compositions of litter in Korean pine (KP), Mongolian Scots pine (MSP) and Dahurian larch (DL) plantations in Laoshan Plantation Experiment Station of Maoershan Experiment Forest Farm of Northeast Forestry University. The results are as follows: (1) The nutrient element content and returning amount in litter varies among different fractional compositions and tree species, the total returning amount of all nutrient elements and the returning amount of K, Ca, Mg, N and P are DL > MSP > KP, the returning amount of Cu is DL > KP > MSP, the returning amount of Fe and Mn are MSP > DL > KP; (2) To KP and DL plantations, the main nutrient element returned is dead needles; dead branches, bark scales and dead cones account for a little proportion; whereas to MSP plantation, besides dead needles, dead branches and bark scales also play an important role in the return of nutrient elements; (3) A little deal of dead leaves can provided a great deal of returning amount of nutrient elements.     

雷竹林营养元素分配与积累

对不同年龄雷竹各器官的N、P、K、Ca、Mg 5种营养元素的含量进行分析.结果表明:雷竹不同器官的营养元素含量大小N、P、Ca、Mg均为叶＞枝＞秆,K为秆＞叶＞枝.各营养元素含量大小顺序为,叶:N＞K＞Ca＞P＞Mg;枝:K＞N＞P＞Ca＞Mg;秆:K＞N＞P＞Mg＞Ca.雷竹林地上部分生物量为34 654.20kg·hm-2,5种营养元素贮藏总量为202.94kg·hm-2.     

山核桃溃疡病与营养元素的关系

调查并分析了安徽省宁国市不同种植区山核桃溃疡病与土壤因子、树皮中营养元素等之间的关系,结果表明:山核桃林分中土壤条件与溃疡病的发生与发展的关系十分密切,其感病指数与土壤密度,树皮中P、Fe的含量呈正相关关系;与土层深度,土壤中N、P、K元素的含量和土壤中有机质的含量及树皮中N、K、M g的含量等呈负相关关系。     

柠条锦鸡儿组培苗继代培养中矿质元素的吸收规律

比较柠条锦鸡儿在MS、WPM、B5三种基本培养基中对P、K、Ca、Mg、Mn、Cu等主要矿质元素的吸收规律,用向量分析方法找出三种基本培养基中的限制因子.结果表明:矿质养分整体供应水平是影响柠条锦鸡儿组培苗吸收矿质元素的关键因子;除此之外,MS培养基的Ca、P水平偏低,WPM和B5培养基的主要限制因子分别为K、Mn和Ca、P、K.     

火炬松人工林养分体内转移与内循环研究

对江苏省下蜀林场火炬松人工林 (15年生 )地上部分养分体内转移和内循环特点进行了初步研究 ,结果表明 :(1)在体内养分转移中 ,叶的贡献最大 ,N、P、K和Mg元素的平均转移量均大于枝和干 ;地上部分养分N、P、K和Mg元素的转移率分别为 44 9% ,34 5 % ,2 0 8%和 30 7%。 (2 )地上部分养分归还量N、P、K、Ca和Mg元素分别 5 5 787,6 13,2 6 70 ,70 79和 2 0 30kg·hm- 2 ·a- 1 分别占需要量的 36 6 7% ,44 6 5 % 5 5 3% ,78 0 2 %和 42 84% ;地上实际消耗土壤中的养分量N、P、K、Ca和Mg分别为 2 2 48,2 13,4 6 4,2 6 98和 7 41kg·hm- 2 ·a- 1 ,分别占吸收量的 2 3 99% ,2 2 76 % ,11 84% ,2 4 32 %和 2 1 0 9%。 (3)与当地的杉木林和次生栎林相比 ,该火炬松人工林养分利用率高 ,并处于养分消耗阶段。     

火焰原子吸收光谱分析法增感效应的研究──Ⅱ．树木叶片铜、铁元素的测定

从７种对ＣＵ、Ｆｅ元素有较大增感效应的有机物中，筛选出邻菲啉作增感剂，用于对杉木、油茶样叶中的Ｃｕ，Ｆｅ元素进行分析测定．结果表明，可使样叶中Ｃｕ，Ｆｅ元素的吸光度增加５０％左右，提高了测定的灵敏度和精度．在相关元素的测定中，除Ｃａ元素的结果表现为偏高外，对Ｋ，Ｎａ，Ｍｇ，Ｍｎ，Ｎｉ和Ｚｎ元素的测定无不良影响．     

Altitudinal patterns of the flora of seed plants of Dawei Mountain in Yunnan Province, south China

Altitudinal gradient incorporates multiple resource gradients, which vary continuously in different fashions. It is important to study the mountain floristic patterns along altitudinal gradients, which reveal the regular pattern of the flora along the environmental gradients, the changing trend of biodiversity patterns along the altitudinal gradient, and relevance of biological fitness. To explore the compositional characteristics and ecological significance of floristic patterns along altitudinal gradient in China National Nature Reserve of Dawei Mountain in the southeast of Yunnan Province, field investigations have been made to the flora along the two routes of the southwest slope and the northeast slope of the said reserve, including a vertical vegetation transect. Meanwhile, further investigations have also been made to the flora of Dawei Mountain, which has been accounted for in the literature, as Flora Yunnan, The Seed Plant in Yunnan, and so on. The structural characteristics of the flora and the altitudinal distribution pattern of its floristic components were analyzed. By applying systematic cluster analysis, the altitudinal position of the dividing line of floristic changes along altitudinal gradient was detected, and the effects of the montane climate on the vertical variation of floristic composition were studied. Conclusions were put forward. This paper can be summarized as follows: (1) The obvious boundary that differentiates tropical floristic elements is located at the altitude of approximately 1,500 m; it is reasonable to stipulate the boundary line between tropical rain forests and the evergreen broad-leaved forests. (2) The vertical vegetation spectrum made by cluster analysis shows that humid rain forests are below 700 m a.s.l, montane rain forests are between 700 and 1,500 m, monsoon evergreen broad-leaved forests are between 1,300 and 1,800 m, and montane mossy evergreen broad-leaved forests are above 1,800 m a.s.l. Nonrepresentative montane mossy dwarf forests (above 2,100 m) in the area are distributed in windward sides and in barren land on the mountain slopes. __________ Translated from Acta Phytoecologica Sinica, 2005, 29(6): 894–900 [译自: 植物生态学报]