可可种质资源多样性与创新利用研究进展

就可可种质资源在起源、分布、传播、分类、鉴定及种质创新与利用等方面取得的研究进展进行综述。可可属植物有22种,仅可可(Theobroma cacao)和大花可可(Theobroma grandiflorum)用于栽培。可可种质资源多样性丰富,其分类研究经历了传统形态学划分的Criollo、Forastero和Trinitario遗传类群到现代分子标记划分的Maran~on、Curaray、Criollo、Iquitos、Nanay、Contamana、Amelonado、Purús、Nacional和Guiana遗传类群。目前,可可的生产性品种选育仍以实生选种和芽变选种为主。分子标记的开发、遗传连锁图谱的构建和全基因组测序的完成,为实现可可分子标记辅助育种提供了技术保障。     

海洋渔业生物增殖放流效果评估研究进展

增殖放流是重要的海洋渔业资源恢复措施,目前该项技术在世界各国大量开展。增殖放流效果评估是 放流工作体系的核心环节之一,根据评估结果,可以不断改进放流技术,使放流效果不断改善。从增殖效果、生态效 果、社会效果3 个方面对国内外海洋渔业生物放流效果评估的主要研究方法和成果进行论述,并对该领域未来的研 究趋势进行展望,可以为放流效果评估工作的高效开展、放流技术的改进提供参考。     

A comparison of three land-based containment systems for use in culturing green sea urchins, Strongylocentrotus droebachiensis (Müller) (Echinodermata: Echinoidea)

Worldwide, most sea‐urchin populations are in decline. Future market demands will likely be met through aquaculture, which may consist of gonad enhancement of wild‐caught sea urchins. In this context, we examined three land‐based containment systems for suitability in maintaining commercial‐size green sea urchins (Strongylocentrotus droebachiensis). Mortality rate, gonad quantity, gonad quality (colour, brightness, firmness, texture) and cleaning efficiency associated with each containment system were the criteria for comparing the effectiveness of the systems (large raceways, small raceways and washtub tanks). After 6 weeks, urchins maintained in large raceways displayed significantly higher mortality rates than urchins maintained in either the small raceways or washtub tanks (mean±SD: 24.3±10.4%, 8.0±3.5% and 4.3±1.5% respectively). Significant differences in cleaning time were detected among the three systems with washtub tanks requiring significantly more cleaning time (0.11±0.02 min urchin^?1) than the other two systems and large raceways requiring significantly less cleaning time (0.06±0.02 min urchin^?1) than the other two systems. No significant differences in gonad characteristics were detected among the three containment systems. Because of the higher mortality rate in the large raceways and the increased cleaning time required for the washtub tanks, the small raceways were considered to be the best of the three systems tested.     

Breaking the crossability barriers between disomic tetraploid Solanum acaule and tetrasomic tetraploid S. tuberosum

Summary A combination of compatible second pollinations and embryo rescue was applied for systematic production of true tetraploid hybrids from crosses between disomic tetraploid Solanum acaule and tetrasomic tetraploid potato, S. tuberosum. Several genotypes of tetraploid potatoes were pollinated with S. acaule, and the compatible second pollinations were made on the following day, with a genotype of S. phureja, IvP 35 to promote fruit development. Embryo rescue was carried out in 21 families, 14 to 27 days after the first pollination. A total of eight plants were obtained from the embryo rescue and their chromosome numbers were counted in the root tips. Three of the eight plants were identified as tetraploid, and five others as diploid. Morphology, isozyme banding patterns, and pollen stainability, as well as potato spindle tuber viroid (PSTVd) resistance, indicated the hybrid nature of the three plants. This is the first report of successful tetraploid hybrid production between disomic tetraploid S. acaule (4x) and tetrasomic tetraploid potatoes. Seed set from the crosses between one of hybrids and diploid potatoes indicated workable levels of both male and female fertility for introgression of valuable genes from S. acaule into the cultivated potato gene pool. The methodology used may be applied to other disomic tetraploid tuber-bearing Solanum species and with some modifications also to distantly related solanaceous species and genera.     

Variation for agronomic and processing traits in Solanum tuberosum haploids × wild species hybrids

Summary The broad range of wild and cultivated species relatives of the commerical potato (Solanum tuberosum L.), guarantees the existence of a gene reservoir to be screened for traits that are absent or present only in low frequencies in the cultivated germplasm. Haploids (2n=2x=24) extracted from the cultivated tetraploid (2n=4x=48) germplasm cross easily with diploid (2n=2x=24) potato species and produce fertile progeny. As most haploid × species hybrids tuberize under long day conditions they can be maintained clonally and evaluated for the traits of interest. Three populations involving Tuberosum haploids × Solanum bukasovii (tub x buk), Tuberosum haploids × Solanum sparsipilum, (tub × spl) and Tuberosum haploids × Solanum berthaultii (tub x ber) clones, were planted at two locations in Wisconsin. The haploids were derived from W231, a selected clone from the University of Wisconsin Potato Breeding Program. The objectives were: to evaluate the H-S populations for agronomic and processing traits, and to determine the phenotypic associations between them. Data were recorded on haulm maturity (HM), tuber weight (TW) and tuber number (NT) per plant, specific gravity (SG), chip color after harvest (CH), and chip color after storage at 4° C and one week of reconditioning at room temperature (CH1). Results for SG and CH indicated good potential of the germplasm evaluated to introgress these traits into the commercial potatoes. For instance, the SG mean for tub x buk, tub x spl and tub x ber were 1.079, 1.086 and 1.082, respectively, and their means for CH were 4.8, 3.9 and 3.5. Chip color after storage and reconditioning was found in low frequency in the populations. Four clones in the tub x spl population, and three clones in the tub x ber population had CH1 4.0, the commercially acceptable score for this trait. Significant (p 0.01) phenotypic correlations (r) were found between HM and SG (r=–0.46 in tub x buk, r=–0.61 in tub x spl, and r=–0.34 in tub x ber), NT and TW (r=0.79 in tub x buk, r=0.88 in tub x spl, and r=0.71 in tub x ber), and TW and SG (r=0.40 in tub x buk, and r=0.36 in tub x spl). The correlation coefficients between processing traits were not significant, which may indicate the presence of separate genetic mechanisms governing the inheritance of these traits.     

Orographic enhancement of wet deposition in the United Kingdom: Continuous monitoring

Continuous monitoring of cloud and rain samples at three mountain sites in the UK has allowed consideration of the long term impact of the enhancement of the wet deposition of pollutants by orographie effects, specifically the scavenging of cap cloud droplets by rain falling from above (the seeder-feeder effects). The concentration of the major pollutant ions in the cloud water is related to the relative proximity of each site to marine and anthropogenic sources of aerosol. In general, the concentrations of major ions in precipitation at summit sites exceed those in precipitation to low ground nearby by 20% to 50%. Concentrations in orographie cloud exceed those in upwind rain by between a factor of five and ten. The results are consistent with seeder-feeder scavenging of hill cloud by falling precipitation in which the average concentration of ions in scavenged hill cloud exceed those in precipitation upwind by a factor of 1.7 to 2.3 for sulphate and nitrate respectively at Dunslair Heights and 1.5 to 1.8 for sulphate and nitrate at Holme Moss. The results suggest that the parameterisation of this relationship with scavenged feeder cloud water concentrations assumed to exceed those in seeder rain by a factor of two for the production of predictive maps of wet deposition in mountainous regions of the U.K. is satisfactory.     

基于Radarsat-2影像的复杂种植结构下旱地作物识别

为提高基于Radarsat-2旱地作物识别的精度,该文研究了一种复杂种植结构背景下具有共同生长期作物的识别方法。研究区为一个12 km×12 km的样方,位于内蒙古上库力农场额很队,以春小麦、油菜2种共同生长期作物为识别对象,利用Spot-6影像和Radarsat-2影像,在数据预处理的基础上分析研究区内典型地物样本的后向散射系数在不同极化波段上的变化特征,根据该变化特征设计图像增强算法,然后基于图像增强后的影像设定合理的阈值实现作物识别提取。结果表明：该方法准确识别并有效提取了共同生长期作物春小麦和油菜的种植面积,总体精度达到97%,Kappa系数为0.96。该方法简便、快捷、可靠,为春小麦、油菜等旱地共同生长期作物种植面积提取提供重要的科学技术支撑。     

Genetic resource enhancement by isolation of diversegenotypes from seed progeny in predominantly sterile rose scentedgeranium Pelargonium graveolens

Four new accessions (BSP1-4) of rose scentedgeranium Pelargonium graveolens were derivedfrom the spontaneous half-sib seed progeny of mostly sterilepopulations of the cultivar accession Bipuli. The seed producingplants of Bipuli had been growing among the populations of cultivaraccessions Hemanti and Kunti in the temperate agroclimate ofKodaikanal, Tamilnadu in India. The four new accessions were comparedwith the cultivar accessions Bipuli, Hemanti and Kunti in fieldexperiments under subtropical agroclimate of Lucknow, Uttar Pradeshfor essential oil yield and quality related traits and in terms oftheir RAPD profiles. The crop yield and essential oil parameters andDNA profiles of the four new accessions and three cultivar accessionsallowed the conclusion that the accessions BSP-1, BSP-2 andBSP-3 were Bipuli × Kunti hybrids and BSP-4was a Bipuli × Hemanti hybrid. The accession BSP-4demonstrated hybrid vigour in several of the essential oil yieldrelated traits; on average basis it out yielded other accessions by afactor of about 2.4. The essential oil of BSP-4 had 89%rhodinol content in which citronellol to geraniol ratio was 1:1 andthe contents of isomenthone, menthone, 10-epi--eudesmol, 6,9-guaiadiene, decanoic acid andisodecanoic acid were relatively lower than in the oils of accessionsBipuli and/or Hemanti. The present study has shown a way for thegeneration of new genotypes in rose scented geranium in which thecultivars have been vegetatively maintained for decades and thegenetic resources are scanty.     

Effects of Delayed Nitrogen Topdressing on Grain Yield and Photosynthetic Characteristics of Flag Leaves of Wheat

Four wheat cultivars were used to study the effects of delayed nitrogen topdressing on popula-tion structure, grain yield and photosynthetic characteristics of flag leaves under high-yielding conditions. Theresults showed that the nitrogen topdressing delayed from overwintering-turning green stage (N1) to turninggreen-jointing stage(N2 ) and jointing-booting stage(N3 ) decreased ineffective tiller in spring, retarded the de-cline of green leaf area and chlorophyll content in late life span, promoted photosynthetic ability of flag leavesand significantly increased the grain yield. N3 treatment was suitable for most wheat cultivars except the geno-types with higher single spike productivity and less ears in unit area.