Evidence for anthropic selection of the Sheanut tree (Vitellaria paradoxa)

The Sheanut tree (Vitellaria paradoxa Gaertn.), a multi-purpose species highly valued for the oil obtained from its seeds, is commonly maintained in the semi-arid parklands of sub-Saharan West Africa. An inventory in the West Gonja District, Northern Region, Ghana, revealed that on intensively farmed land this species constituted 79.7 ± 7.2% (Basal area = 2.19 ± 0.64 m² ha⁻¹) of the woody biomass, on low intensity farmland 84.2 ± 10.0% (2.16 ± 0.57 m² ha⁻¹) and only 10.2 ± 3.3% (0.92 ± 0.23 m² ha⁻¹) in unmanaged woodland, with similar environmental characteristics. No significant differences were found between total Sheanut tree densities on different land use intensities, although as a proportion of all trees surveyed, large trees were more common on farmed land. Participatory surveys revealed that these populations are a direct result of anthropic selection as local farmers eliminate unwanted woody species on farmland, leaving only those Sheanut trees that meet criteria based on spacing, size, growth, health, age and yield. Characteristics that could affect population dynamics during traditional management and harvesting including short viability seeds and cryptogeal germination are also discussed with reference to unconscious selection. Tree improvement is currently constrained, as true to type varieties are difficult to propagate. It is proposed that Sheanut trees on farmland are semi-domesticated having been subject to long-term anthropic selection during cycles of traditional fallow and crop cultivation. This revised version was published online in June 2006 with corrections to the Cover Date.     

蒺藜苜蓿SSR反应体系优化及在一年生苜蓿种质鉴定中的应用

利用正交设计和完全随机试验优化蒺藜苜蓿(Medicago truncatula Gaertn)SSR标记的PCR反应体系。结果表明,适合于一年生苜蓿(Medicago L.)遗传分析的SSR技术体系为:10μL反应体系中TaqDNA聚合酶为1U,dNTP浓度为0.20mmol/L,Mg²⁺浓度为2.0mmol/L,引物浓度为1.5umol/L,模板DNA用量为20ng/uL;利用该反应体系将2个蒺藜苜蓿亲本和杂交种有效鉴别;利用SSR标记对19个一年生苜蓿种质进行SSR-PCR扩增,用8%的非变性聚丙烯酰胺凝胶电泳检测,不同种质间DNA谱带多态性丰富,通过UPGMA方法聚类分析可以明确区分19个一年生苜蓿种质。     

仙茅属13个种群遗传多样性ISSR分析

为了解我国仙茅属植物种质资源分布情况及其亲缘关系,利用ISSR技术对来自湖南、广西、四川、云南、江西的13个种群的134份野生样本的遗传多样性进行了研究。利用筛选出的15条引物共扩增出256条清晰、重复性好的条带,多态性条带百分比达到91.79%;在种内水平上,多态性位点百分比为4.69%~29.30%,Shannon信息指数为0.028 3~0.160 5。13个种群中遗传多样性最高的为四川宜宾种群,多态性位点百分率为29.30%,Shannon多样性指数为0.160 5;云南9号种群遗传多样性最低,多态性位点百分率为4.69%,Shannon多样性指数为0.028 3。13个种群之间的遗传距离为0.187 1~0.513 1。根据遗传距离进行UPGMA聚类分析,13个种群共聚为2大类,四川宜宾与江西武功山种群最先聚在一起,二者的亲缘关系最近;广西雅长与四川盐边的种群聚在一起,说明二者亲缘关系较云南的较近。     

莲藕片真空微波联合气流膨化干燥工艺

为优化莲藕片真空微波-气流膨化联合干燥工艺,本试验在单因素试验的基础上,采用三因子二次正交旋转组合设计,探讨了单位质量微波功率、转换点含水率和膨化温度对产品的亮度、硬度、脆度和水分含量的影响,并对变量进行了响应曲面分析.结果表明:单位质量微波功率、转换点含水率和膨化温度对莲藕脆片的品质指标有显著影响.真空微波联合气流膨化干燥莲藕片工艺的最优参数组合为:单位质量微波功率12.48W·g-1,转换点含水率48.73％,膨化温度86.56℃.优化莲藕片的生产工艺可为莲藕片工业化生产提供参考.     

日本“肯定列表制”对中国莲藕出口的影响

笔者通过分析比较了日本“肯定列表制”和中国无公害蔬菜规定的农业化学品的残留限量标准。得出:“肯定列表制”对莲藕等蔬菜的农业化学品的残留限量标准种类多,要求严格,对中国莲藕等蔬菜产品的对日出口增加了难度。“肯定列表制”实施3个多月来,中国的莲藕的出口量和创汇额与2005年“肯定列表制”实施前同期相比分别下降了约7.7%和6.6%。对照“肯定列表制”,中国的无公害标准简单,欠具体,农民和莲藕加工出口企业在生产和加工中对“肯定列表制”的认识和重视不够,原料基地建设不能满足加工出口的需要等是中国莲藕生产和加工中存在的主要问题。按“肯定列表制”的要求完善中国的莲藕标准化生产体系,引导农民按标准组织生产,帮助企业建立生产基地,提高莲藕产品的深加工程度,拓展日本以外的出口市场等,是促进中国莲藕出口的有效途径。     

Molecular analyses of genetic variability in soap nut (Sapindus mukorossi Gaertn.)

Sapindus mukorossi Gaertn. (Sapindaceae) is commercially an important plant much valued for its fruits commonly known as soap nut as well as for the seed oil used as a feed-stock for biodiesel production. Molecular polymorphism, determined, using three single primer amplification reaction (SPAR) methods (RAPD, DAMD and ISSR) is used to assess the genetic variability in 69 accessions of S. mukorossi Gaertn., encompassing different geographical regions in India. Cumulative band data generated using the three SPAR methods resulted in 82.49% polymorphism across all genotypes of S. mukorossi Gaertn. UPGMA tree showed two major clusters that were in accordance with the geographical diversity. The intra-population genetic diversity (0.16), Shannon information index (0.24) and polymorphic loci (45.62%) were highest in AS population, while the corresponding lowest values were recorded in HP population. The inter-population average distance ranged from 0.05 (GA and HP) to 0.26 (AP and HP). Based on these distances, the UPGMA tree for the populations was computed, which showed the presence of two major clusters. Cluster I contained all the populations from Himachal Pradesh (HP) and Uttarakhand (GA and KU) and cluster II grouped the populations from North Eastern region (AS, AP, MG). The present study showed that SPAR methods are informative and useful to unravel the diversity among different populations of the soap nut plants and is a prelude for further utilization of promising and genetically divergent materials in the breeding programmes.     

无患子嫁接试验研究

探索无患子的最佳嫁接时间及嫁接方法:于2006年1月至4月,采用了四种嫁接方法进行嫁接试验。结果表明:不同嫁接时间的成活率差异显著,2～3月最适宜嫁接;不同嫁接方法对成活率的影响较显著,劈接效果最好,成活率高。     

海南岛莲雾害虫

报道了海南岛莲雾害虫２３号，并记述了主要害虫角盲蝽、莲雾瘿木虱、蓝绿象及白裙赭夜蛾的为害、形态、生物学特性及防治方法。     

超干处理对沙芥属蔬菜种子活力及抗氧化代谢的影响

【目的】研究超干处理对沙芥属蔬菜种子活力及抗氧化代谢的影响,为沙芥属蔬菜种子耐干性及贮藏提供理论基础。【方法】采用硅胶干燥法将沙芥种子（4.5%）和斧形沙芥种子（4.3%）的含水量分别降至3.1%、2.2%、1.3%,测定不同含水量条件下种子的生活力及抗氧化代谢的变化。【结果】种子含水量由CK降至1.3%时,斧形沙芥种子活力保持较高水平,而沙芥种子则急剧下降;脱水后3个含水量的沙芥和斧形沙芥种子的相对电导率均低于CK,细胞膜完整性保持良好;超干处理会使沙芥属蔬菜种子的MDA含量和 产生速率增加;超干处理对种子内4种抗氧化酶（SOD,CAT,GPX,APX）活性无明显影响。【结论】沙芥和斧形沙芥种子均具有较强的耐干性,但斧形沙芥种子抵御伤害的能力及种子的耐干性均强于沙芥种子,含水量2.2%是沙芥种子发芽率和活力的转折点。     

莲藕膨大过程中碳水化合物变化的初步研究

在莲藕膨大过程中，测定其干物质、淀粉、可溶性总糖、还原糖、可溶性蛋白质等含量，研究碳水化合物的变化规律。结果表明：干物质、淀粉和可溶性蛋白质含量在莲藕膨大过程中均逐渐上升，至膨大后期有一个急增过程；还原糖含量先有所上升，膨大中期迅速下降，至膨大后期维持较稳定水平；可溶性总糖含量从膨大始期至膨大中期平缓上升，至膨大后期则迅速增加。莲藕根状茎的储藏物质主要为淀粉。