广东省高州市园林植物冻害调查与冻害后处理方法

通过调查冻害发生后本地绿化植物受害程度以及灾后救治,提出对冻害植物进行适时适度修剪,科学的肥、水管理,强化树体,及时防治病虫害,是快速恢复绿化树生势的有效方法。同时,建议合理利用乡土植物,以减少绿化树的冻害。     

Effect of Indigenous Nitrogen Supply of Soil on the Grain Yield and Fertilizer-N Use Efficiency in Rice

The effects of application of N fertilizer on wheat on the grain yield and N use efficiency （FNUE） of rice in the wheat-rice rotation system, as well as on the soil fertility were studies. N-fertilizer application on wheat significantly increased total N, arnrnoniurn-N and nitrate-N contents in paddy field, resulting in high indigenous N supply of soil （INS）. Compared with low INS, the effect of N rate on the grain yield of rice was reduced significantly, and FNUE was decreased under high INS. These results indicated that high INS was one of the main reasons for the low FNUE in rice.     

云南地方稻种Wx基因第一内含子供体+1位碱基变异与直链淀粉含量的关系

应用PCR一步法对来自云南省14个地州、55个市/县的220个籼、粳地方稻种Wx基因第一内含子供体+1位碱基G/T进行了检测,同时用PCR Acc I酶切法对其中的101份进行验证,结果表明两种方法检测结果一致。根据G/T碱基将220个供试材料分为GG、TT两种基因型。云南地方稻种以GG型占优势,有164个,占74.5%;TT型有56个,占255%;籼稻中80.5%属GG型,粳稻中67.0%属GG型。GG型直链淀粉含量较高,平均18.97%,TT型较低,均低于16%, GG、TT基因型之间的平均直链淀粉含量差异极显著。G/T与直链淀粉含量存在密切的联系,其相关系数为0733**。GG型品种中有33个直链淀粉含量较低（3.91%～15.93%）,多数为来源于云南西南部傣族地区的品种。籼稻中的GG型或TT型品种与粳稻中的GG型或TT型品种间平均直链淀粉含量无显著差异,表明GG/TT基因型在籼粳不同遗传背景下直链淀粉表达无显著差异。     

云南地方稻种的多样性及优异种质研究

 以5285余份云南地方稻种资源为研究对象进行云南地方稻种的多样性及优异种质研究。结果表明：（1）云南是中国稻种最大的遗传和生态多样性中心及其天然宝库，不仅性状间多样性存在较大差异，更重要的是地州间的多样性差异也十分明显，云南稻种资源的多样性大致可划分为多样性中心区、多样性扩散区和多样性贫乏区。（2）云南是中国稻种优异种质的富集中心, 云南地方稻种是开展中国稻种资源核心种质研究的最佳材料。（3）以云南地方稻种为研究对象开展云南稻种核心种质库的构建工作，不仅可以构建理想的核心种质库，而且可以明确核心种质的系统发生规律和建立优异核心种质动态基因库     

The impact of indigenous soil and water conservation practices on soil productivity: examples from Kenya,Tanzania and Uganda

Farmers in many parts of Africa use indigenous soil and water conserving (ISWC) practices as an integral part of their farming systems. Farmers have developed such methods which have maintained productivity and contributed to long‐term sustainability, while introduced measures have often been rejected or simply failed to achieve their technical objectives. This paper examines the strengths and weaknesses of some ISWC practices in Kenya, Uganda and Tanzania. An evaluation has been carried out based on farmers' evaluation criteria as well as criteria identified by researchers. Farmers' criteria are often based on the quality of their natural resources (farmers are more likely to conserve those soils that will give the highest return on their investment), the resource level of the household (particularly income levels and labour availability), cropping intensity as well as cultural traditions related to age, education and gender. Of great importance, however, is the need to maintain or increase soil productivity. Methods that conserve moisture, reduce soil erosion, maintain soil fertility and increase productivity, which are socially acceptable and economically viable, are those which farmers favour. ISWC practices often have these qualities but farmers have not always been able to adjust the techniques to rapid changes in farming systems and increasing intensity of land use. Soil productivity and economic modelling indicate that although yields declines are lower when traditional technologies are used, long‐term productivity remains a problem. There is an urgent need to work closely with farmers to improve and develop traditional SWC techniques. Copyright © 2000 John Wiley & Sons, Ltd.     

Genetic diversity of mtDNA D-loop sequences in four native Chinese chicken breeds

1. To explore the genetic diversity of Chinese indigenous chicken breeds, a 585 bp fragment of the mitochondrial DNA (mtDNA) region was sequenced in 102 birds from the Xichuan black-bone chicken, Yunyang black-bone chicken and Lushi chicken. In addition, 30 mtDNA D-loop sequences of Silkie fowls were downloaded from NCBI. The mtDNA D-loop sequence polymorphism and maternal origin of 4 chicken breeds were analysed in this study.

2. The results showed that a total of 33 mutation sites and 28 haplotypes were detected in the 4 chicken breeds. The haplotype diversity and nucleotide diversity of these 4 native breeds were 0.916 ± 0.014 and 0.012 ± 0.002, respectively. Three clusters were formed in 4 Chinese native chickens and 12 reference breeds. Both the Xichuan black-bone chicken and Yunyang black-bone chicken were grouped into one cluster. Four haplogroups (A, B, C and E) emerged in the median-joining network in these breeds.

3. It was concluded that these 4 Chinese chicken breeds had high genetic diversity. The phylogenetic tree and median network profiles showed that Chinese native chickens and its neighbouring countries had at least two maternal origins, one from Yunnan, China and another from Southeast Asia or its surrounding area.     

Mortality Patterns in Dairy Animals under Organized Herd Management Conditions at Karnal India

Mortality patterns of two Zebu cattle breeds, Sahiwal and Tharparkar, and two crossbred strains, Karan Swiss and Karan Fries, maintained at the National Dairy Research Institute, Karnal were studied. Nine-year (1989--90 to 1997--98) data on mortality were analysed for year, season, age and cause effects on mortality rate. The overall mortality was 14.17%. The mortality in Sahiwal, Tharparkar, Karan Swiss and Karan Fries averaged 14.35%, 7.21%, 17.12% and 13.46%, respectively. The breed mortality rate did not vary significantly between years, seasons, age categories and causes of disease. However, the trends indicated appreciable difference in mortality rates. The mortality was highest in the year 1994--95 (19.53%) and lowest in 1991--92 (8.56%). There was very little variation in seasonal mortality rate and mortality rate averaged 4.53%, 4.81% and 4.84% in hot-dry (March-June), hot-humid (July-October) and cold (November-February) seasons, respectively. The mortality up to 2 months of age accounted for a major share (50-60% or higher) in different breed groups. Digestive problems followed by respiratory disorders together accounted for 70-80% of total deaths.     

12个中国地方鸡种群体遗传结构及遗传多样性分析

利用29对微卫星引物对我国的12个地方鸡种进行群体遗传结构及遗传多样性评估，结果表明：每个座位的等位基因数从2到23不等，所有的12个群体均显示较高水平的杂合度，固始鸡最低，为0．4532，大骨鸡最高，为0．6271。鸡种间存在较大的遗传分化，16．7％的遗传变异源于品种间的差异。基于Reynolds’遗传距离的邻近（NJ）聚类图显示，12个群体可以分为2个主要的类群：重体型的鸡种首先聚在一起，然后轻体型鸡种加入。structure程序同时也被用于评价鸡种间的遗传关系，结果与NJ聚类法相似，重体型的鸡种首先与轻体型鸡种分成两类。     

佤族野生食用植物资源的民族植物学研究

沧源佤族自治县拥有142 820佤族人口,是云南省佤族分布最多的一个县。通过对文献资料的查阅收集和整理,以当地佤族人为向导,运用民族植物学研究方法对沧源野生食用植物资源进行调查。结果表明,沧源佤族民间传统食用野生植物有105种,隶属52科78属。根据民间的食用用途,当地民间野生食用植物可分为野生蔬菜、野果、调味品3种主要类型。其中可作为野生蔬菜食用的有69种,野果有34种,用于调料的植物有8种,野生食用植物以幼嫩枝叶（60.95%）和果类（39.05%）为主。佤族野生食用植物的传统知识,在食物新资源的开发利用方面具有重要的参考价值。     

云南13种乡土绿化树种对SO2、NO2气体反应的研究

采用人工模拟熏气的方法,研究了13种云南乡土绿化树种对城市SO2、NO2有害气体的反应.结果表明云南红豆杉、长梗润楠、翠柏、滇润楠、麻栗坡含笑、南亚含笑、山玉兰对SO2气体的抗性弱,而云南含笑、脉叶虎皮楠、川滇三角枫对SO2气体的抗性最强,灯台树、川滇三角枫净化SO2的能力较强,其净化量分别为300mg·kg-1、700 mg·kg-1.NO2浓度为1.0 mg·m-3时,长梗润楠、云南含笑、云南拟单性木兰、云南红豆杉、麻栗坡含笑、灯台树叶片的N净化量依次为2 000 mg·kg-1、1 100 mg·kg-1、1 700 mg·kg-1、2 300 mg·kg-1、1 200 mg·kg-1、13 100 mg·kg-1.经综合比较川滇三角枫对SO2气体具有较好的抗性和净化能力,而对NO2气体具有较好的抗性;云南含笑、云南拟单性木兰、脉叶虎皮楠等树种对SO2、NO2气体具有较好的抗性和净化能力.