以色列野生二棱大麦籽粒氮素含量的基因型及其生态差异

为了筛选极端蛋白质含量或氮素营养含量的大麦材料,以采自以色列不同生境的9个群体90个野生大麦基因型为试验材料,分别于2012年和2013年种植于黔中地区4个环境条件下（Y2012 Farm、Y2013 AS、Y2013 Garden和Y2013 9F）,测定并比较其籽粒可溶性蛋白质和总氮含量。结果显示,Y2012 Farm环境下的籽粒总氮含量显著高于Y2013 AS环境;Y2013 AS环境下的籽粒可溶性蛋白含量显著高于其他3个环境;在Y2012 Farm 和Y2013 AS两个环境下,籽粒总氮含量最高的是Tabigha群体,最低的分别是Golan High和Hermon群体,两者均与Tabigha群体有显著差异;Y2012 Farm、Y2013 AS及Y2013 Garden 3个环境中,Gilboa群体的可溶性蛋白质含量均显著高于其他群体,说明野生二棱大麦籽粒氮素营养积累既受种植环境的影响,又有一定的保守性。Y2012 Farm 和Y2013 AS两个环境下,总氮含量较高的基因型有T8、R23和R3,分别为3.42%、3.04%和3.12%,较低的基因型是GN26,平均值为2.01%。综合比较发现,在供试的野生二棱大麦基因型中,有利用价值的氮素含量极端高和低的基因型分别为T8和HM17,可用于现代栽培大麦的改良。     

Analysis of Yam Minisett technique adoption in Nigeria

White yam (Dioscorea rotundata Poir.) is an important tuber crop grown throughout West Africa, the Caribbean, and Latin America. Propagation of the crop is primarily vegetative, through the use of small whole tubers (seed yams) and cut pieces of tuber (setts) planted to produce the larger tubers (ware yams) that households consume and sell. The Yam Minisett Technique (YMT) was introduced in Nigeria in the late 1970s as a means of increasing the production of seed yams. The YMT is different from many other agricultural technologies in that it requires farmers to do something – cut their tubers into small pieces – which they feel based on experience is potentially damaging as it causes rot. Indeed, the existing literature suggests that adoption of the YMT tends to be low and variable. However, to date there has been no systematic analysis of the existing literature on YMT adoption designed to explore which factors are reported to be the most important and why. Hence, the objective of this paper is to analyze the YMT adoption studies published to date to explore which factors are particularly important, and how this may help guide future research in YMT adoption. The results suggest that uncertainty – risk and ambiguity aversion – as perceived by farmers is a key consideration in YMT adoption and needs to be considered in future work.     

Ovarian development and nutritional quality changes of the wild‐caught Portunus trituberculatus during the artificial fattening period

A female swimming crab (Portunus trituberculatus) with fully developed ovaries is considered one of the most nutritious types of seafood. The fishing yield of P. trituberculatus in China has always been high; however, its economic value has been low and unreliable due to poor ovarian development and low nutritional value. Artificial fattening is an effective way to improve the value of wild‐caught crabs, and this study focused on analysing the ovarian development and nutritional quality of the female P. trituberculatus during an artificial fattening period. Therefore, this study provides scientific evidence on the effects of artificial fattening on female P. trituberculatus and can guide the development of nutritional quality regulations for wild‐caught female crabs during the fattening process. The results showed that the ovaries of the wild female P. trituberculatus developed gradually. The ovarian morphology became bulkier, while the gonadosomatic index (GSI) and total edible yield (TEY) were significantly improved after artificial fattening. Significant changes in the nutritional components of the edible tissues were observed, and the moisture content in the ovaries and hepatopancreas decreased continually, while both the protein and fat content in the ovaries significantly increased. Moreover, the fat content in the hepatopancreas significantly increased. The saturated fatty acids(ΣSFA) in the ovaries and hepatopancreas had an increasing trend after fattening, while ΣPUFA and Σn‐3PUFA first decreased and then increased. In contrast, the ratio of Σn‐3PUFA to Σn‐6PUFA decreased steadily. However, the fatty acid composition of the muscles did not change significantly. The levels of all the amino acids increased continuously during the fattening process, and EAA increased significantly in the early stages of the fattening period. Consequently, all amino acids became nonlimiting amino acids after fattening. Furthermore, the ratio of EAA/NEAA in the ovaries increased continually until the end of the fattening period. On the other hand, the fatness and TEY increased significantly after artificial fattening. In addition, the nutritional value significantly improved with the exception of the high‐quality fatty acids in the ovaries and hepatopancreas, which were slightly lower in both.     

长白山野生观赏植物引种与栽培试验

1999～2003年,将采收的野生种子、直接到野外采挖等方式直接获取的种源,按其种类进行适当的处理和保存后,通过播种、扦插、分鳞茎、块茎等方式扩繁,并采取防治病虫害和合理施肥等措施,对长白山野生观赏植物40科117属170种进行了栽培试验,并记录了其物候观测结果,以探讨其生态习性及繁育栽培技术。试验证明,长白山野生观赏植物具有适应性较强、管理粗放等特点。     

<Emphasis Type="Italic">Ziziphus </Emphasis><Emphasis Type="Italic">spina-christi</Emphasis> (L.) Willd.: a multipurpose fruit tree

Neglected and underutilized species often play a vital role in securing food and livestock feed, income generation and energy needs of rural populations. In spite of their great potential little attention has been given to these species. This increases the possibility of genetic erosion which would further restrict the survival strategies of people in rural areas. Ziziphus spina-christi is a plant species that has edible fruits and a number of other beneficial applications that include the use of leaves as fodder, branches for fencing, wood as fuel, for construction and furniture making, and the utilization of different parts e.g. Fruits, leaves, roots and bark in folk medicine. Moreover, the plant is adapted to dry and hot climates which make it suitable for cultivation in an environment characterized by increasing degradation of land and water resources. Lack of research in Z. spina-christi hinders its successful improvement and promotion. Therefore, studies are needed to fully exploit this species. This article aims at summarizing information on different aspects of Z. spina-christi to stimulate interest in this crop which is of importance in Sudan and other countries of the semi-arid tropics.

Cattle depredation by puma (Puma concolor) and jaguar (Panthera onca) in central-western Brazil

In this study, data on cattle depredation by puma (Puma concolor) and jaguar (Panthera onca) were recorded for six years (1998-2003) in a cattle ranch in central-western Brazil. Depredation represented 18.9% of the overall cattle mortality, being predominant on calves. In biomass, kills represented 0.4% (63.8 kg/km²) of the ranch’s annual stock. In economic loss, kills represented 0.3% of the cattle stock value. Depredation was mainly associated with cattle’s age class and location along with the time of birth of calves. The proportion of pastures next to forest with depredation (n = 33, 48.5%) was not distinguished to the proportion of pastures not bordering forest with depredation (n = 35, 51.5%). However, the proportion of pastures next to forest with depredation represented 54% (n = 33) of the 61 total pastures that were at least partially surrounded by forest patches or riparian forests that comprised eight continuum blocks of forest fragments of different sizes in the ranch and adjacent areas. No kills occurred in the central portion (main house) of the farm, close to the headquarters where the pastures not bordering forest. The distances of the kills in relation to areas of native forest was 1317.48 ± 941.03 m. In order to reduce depredation, calves should be kept as far as possible from forest areas and concentrated cattle breeding and calving seasons should be encouraged.     

麻山药收获机振动松土装置的设计

针对麻山药收获机械化水平低、机械挖掘根茎损伤率高及人工拔出根茎劳动强度大等问题,结合麻山药收获农艺需求与麻山药的物理机械性质,设计了4F-2型麻山药收获机的振动松土装置。确定了振动松土装置的设计方案,建立了振动松土装置的特征模型;并运用ADAMS软件对机组前进速度、偏心轮转动速度和偏心距进行运动仿真分析,结果表明:机组前进速度为3m/min、偏心轮转动速度为540r/min、偏心距为50mm时性能最优。优化后振动松土装置的麻山药收获机田间试验结果表明:人工拔出根茎轻松省力,根茎的损伤率为3. 5%,满足企业标准《Q/JL001-2016麻山药收获机》相关要求。     

野生大豆和不同栽培大豆品种在镉胁迫下种子萌发及幼苗生长的差异

为探讨野生大豆和不同栽培大豆品种在镉胁迫下种子萌发的差异,筛选优质的大豆耐镉资源,首先比较5种镉浓度(5,10,25,40 mg·L^-1)对野生大豆与栽培大豆的种子发芽率、发芽势、发芽指数、活力指数、根长及芽长等参数,筛选出对镉敏感的性状及适中的镉浓度处理;然后以此为基础比较野生大豆1503、超高产大豆(沈农9号和辽豆14)及普通栽培大豆(辽豆16和沈农20)耐镉性差异。结果表明:野生豆1503和栽培豆辽豆16种子的发芽率、发芽势及发芽指数在较高浓度(25或40 mg·L^-1)处理时明显下降,其它浓度处理与对照差异不明显或者高于对照,而活力指数、根长及芽长等指标在较低浓度(5或10 mg·L^-1)处理时就表现明显的被抑制效应,尤其对根长抑制更明显。活力指数、根长及芽长对镉胁迫更为敏感,可以作为鉴定耐镉材料及监测镉胁迫对植物的影响的重要指标。在5 mg·L^-1镉处理下,1503的活力指数、根长、芽长与对照差异不显著,10 mg·L^-1时显著下降,辽豆16在5 mg·L^-1时3种参数显著低于对照,因此镉浓度5 mg·L^-1的处理适中,可用来比较不同品种的耐镉性。在5 mg·L^-1镉处理下,按照3个敏感性状的平均值,筛选出耐镉性较强野生豆1503,镉性较弱的栽培豆沈农20,可用于耐镉育种及耐镉机制研究。     

壳聚糖及UV-C处理对长山药冷害和品质的影响

为探讨壳聚糖及UV-C处理对贮藏过程中长山药冷害和品质的影响,以长山药为试验材料,采用不同浓度的壳聚糖及不同剂量的UV-C照射处理长山药块茎,对比分析长山药的冷害指数、可溶性固形物、丙二醛(MDA)、相对电导率、抗氧化酶类活性等指标的变化。结果表明,维持长山药块茎品质的壳聚糖最佳浓度为1.0%,UV-C最佳照射剂量为6 KJ·m^-2。此条件下,壳聚糖、UV-C、壳聚糖+UV-C处理都能有效降低长山药块茎的冷害指数,抑制其MDA含量和相对电导率的升高,保护膜结构的完整性,显著降低了多酚氧化酶(PPO)活性,还可以保持较高的可溶性固形物含量和过氧化物酶(POD)活性,说明这3种处理均可控制长山药冷害的发生,延长块茎的贮藏期,其中以壳聚糖+UV-C处理效果最佳。本研究结果为减缓采后长山药冷害提供了一定的理论依据。     

Persistence over time,overlapping distribution and molecular indications of interspecific hybridization in wild potato populations of Northwest Argentina

Solanum gourlayi and Solanum spegazzinii, wild potatoes endemic to Argentina, possess desirable traits for breeding. In periodical regenerations of accessions, variability was detected for morphology and breeding barriers. The persistence of these populations in nature was evaluated after more than 20 years. Both species were observed in all visited sites, along with other wild and cultivated potatoes. Chromosome numbers coincided with the originally reported, except for one population of Solanum gourlayi, with diploid and tetraploid cytotypes. The accompanying flora and environmental conditions revealed important alterations as the result of road construction, excessive stocking rates and overgrazing. Principal coordinate and cluster analyses and an AMOVA using AFLP data of three original accessions and the corresponding new accessions revealed high molecular variability and extensive overlapping. Plant grouping of accessions occurred at a distance of 0.58 for S. gourlayi, 0.62 for S. spegazzinii and 0.67 for both species. The role of natural hybridization and sexual polyploidization in the evolution of sympatric populations of wild potatoes is discussed.