陕西安康烟区生育期气候综合指数对烤烟化学成分的影响

为了明确烤烟不同生育期气候资源对烟叶品质的贡献率，以陕西安康烟区2002—2011年气象资料和烟叶化学成分为材料，采用主成分分析法，对烤烟不同生育期的平均温度、降水量和日照时数进行分析，构建不同生育期的气候综合指数(CCI)；采用相关分析、通径分析和决策分析对各生育期CCI与烟叶化学成分的关系进行分析。结果表明：不同生育期CCI对烟碱含量的影响以采烤前期最大，旺长期最小，对采烤前期的影响主要为直接作用；对烟叶总糖含量的影响以采烤后期最大，采烤前期最小，对采烤后期的影响主要为直接作用和通过旺长期的间接作用；对烟叶糖碱比的影响以采烤后期最大，旺长期最小，采烤后期的影响主要为直接作用和通过采烤前期的间接作用。     

基于SRAP的西瓜种质资源遗传多样性评价

运用SRAP分子标记技术分析了80份西瓜种质资源的遗传多样性，28对不同的引物组合共扩增出308条谱带，其中多态性谱带68条。引物组合的多态性频率最低为9.1%，最高为45.5%，平均22.1%。基于全部材料的SRAP基因型数据评价品种间的遗传关系，80份西瓜种质的遗传相似系数变化范围在0.94～1.00之间，表明供试西瓜种质资源的遗传背景比较狭窄。利用NTSYS软件聚类分析，80份西瓜材料被划分为3个类群，类群间相似度较高。来源地不同的西瓜材料也被划分到一个类群，进一步说明供试材料遗传背景狭窄。西瓜育种要取得突破性进展，必须加强种质资源的引进与创新。     

Complexity of indica-japonica varietal differentiation in Bangladesh rice landraces revealed by microsatellite markers

To understand the genetic diversity and indica-japonica differentiation in Bangladesh rice varieties, a total of 151 accessions of rice varieties mostly Bangladesh traditional varieties including Aus, Boro, broadcast Aman, transplant Aman and Rayada varietal groups were genotyped using 47 rice nuclear SSRs. As a result, three distinct groups were detected by cluster analysis, corresponding to indica, Aus and japonica rice. Among deepwater rice varieties analyzed some having particular morphological features that mainly corresponded to the japonica varietal group. Some small seeded and aromatic varieties from Bangladesh also corresponded to the japonica varietal group. This research for the first time establishes that the japonica varietal group is a prominent component of traditional varieties in Bangladesh, particularly in deepwater areas.     

不同熟期荔枝品种的枝梢生长节奏的初步研究

本试验以3-4年生的早熟（‘三月红’）、中熟（‘妃子笑’）、晚熟（‘糯米糍’）及特迟熟（‘马贵荔’）荔枝品种为试材，比较不同成熟期荔枝品种周年的枝梢生长节奏及新叶发育过程中叶绿素指（SPAD）数动态。结果表明：各品种枝梢伸长生长具有一定差异，但都具有一定的节奏性，而枝梢增粗生长周年持续进行，无明显节奏特征；叶绿素指数达到最高值的80%时增加缓慢，因此叶绿素指数达最高值的80%时作为枝梢成熟的标准，用来确定枝梢成熟的时间。     

Relationship between Geographical Distribution of Pinus yunnanensis and Climate

A distribution map of Pinus yunnanensis was made according to the data on geographical distribution of P.yunnanensis by means of applying geographic information systems software ArcGIS, and the climatic parameters of the distribution areas for P.yunnanensis were determined by the climate forecast model Climate China.The relationship between the geographical distribution of P.yunnanensis and the climate was studied by adopting the indexes of Kira including the warmth index(WI),coldness index(CI) and aridity index (K),Xu’s humidity index(HI),Holdridge’s life temperature(BT),potential evapotranspiration (PET),potential evapotranspiration ratio(PER) and the single factors as the mean annual temperature, the mean temperature in January,the mean temperature in July,the mean annual precipitation, the>5℃accumulated temperature,the>18℃accumulated temperature,the maximum temperature, the minimum temperature,the temperature variation, the ratio of temperature and precipitation of the year, etc.And the Kira’s water-temperature indexes on distributional upper limit,low limit and north limit were discussed.The major climatic factors effecting the distribution of P.yunnanensis were screened out by statistical analysis software SPSS and the results showed the impact factors are in the order of temperature>humidity>the temperature difference between mean warmest month temperature and mean coldest month temperature.     

双抗虫基因三倍体毛白杨对舞毒蛾幼虫的抗性研究

用室内群体饲养舞毒蛾幼虫的方法,对15个双抗基因三倍体毛白杨株系进行饲虫试验。结果表明:校正死亡率划分了高抗、中抗、低抗虫植株,舞毒蛾校正死亡率在95以上为高抗株系;40～75为中抗株系,30以下为低抗株系。舞毒蛾的发育历期、蜕皮指数和毒效反映的规律相一致。     

贵州野生枇杷资源遗传多样性的ISSR分析

本文采用ISSR标记，构建了贵州39份野生枇杷种质的DNA指纹图谱，并对其遗传多样性进行了评价。结果表明，以筛选出的15条引物进行PCR扩增，获得清晰、重复性好的谱带125条，其中多态性谱带108条，多态性比例为86.4%；应用引物815、825和841的组合，构建了39份枇杷种质的ISSR指纹图谱，可以有效区分所有供试材料；15条引物的谱带数据聚类分析表明，供试种质的遗传相似性系数为0.40~0.98，在相似性系数为0.70时，可将供试种质分成五大类。聚类结果与种质表型相关，与地理分布的相关性不明显。     

Prospect of Evaluation Study on Vegetation Degradation

Vegetation degradation is related to the stability and succession process of ecological systems.This paper combed and screened the recent national and international research on vegetation degradation,and discussed vegetation degradation research in terms of selection of reference ecosystem for evaluation,selection of evaluation index system and the selection of evaluation methods.At last,the direction of vegetation degradation research was predicted and prospected.     

木粉/PVC复合材料挤出流动性的影响因素

研究木粉的粒径、添加剂的种类及配比等因素,对木塑复合材料挤出流动性的影响.结果表明:木粉粒径越小,复合物料在挤出过程中的流动性能越差,所制备的木塑复合材料色差越大,且产品材色越深.综合考虑加工特性和制品材色,宜选用木粉粒径45～60目；并添加稀土热稳定剂及铝酸酯偶联剂,可以提高物料的挤出流动性.     

Responses of Components of Antioxidant System in Moongbean Genotypes to Cadmium Stress

Four genotypes (Pusa 9531, Pusa 9072, Pusa Vishal, PS‐16) of moongbean [Vigna radiata (L.) Wilczek] grown in earthen pots were treated with cadmium at 0, 25, 50, and 100 mg kg^?1 soil. Cadmium tolerance (CdT), the ability of a plant to maintain growth at high levels of cadmium (Cd), was calculated as the ratio of dry‐matter production in the untreated and the Cd‐treated soils. The moongbean genotypes showed a differential response to Cd concentrations; Pusa 9531 was identified as Cd tolerant, whereas PS 16 was Cd susceptible. To find out the physiological basis of these differences, we investigated the possible role of antioxidant (enzymatic and nonenzymatic) defense systems. Activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), ascorbate peroxidase (EC 1.11.1.11), and glutathione reductase (EC 1.6.4.2) and the amounts of ascorbate and glutathione were monitored in the Cd‐tolerant and Cd‐sensitive moongbean genotypes. The results revealed the presence of a strong antioxidant defense system in the Cd‐tolerant genotype (Pusa 9531) for providing adequate protection against oxidative stress caused by Cd.