Discrimination of haploid and diploid maize kernels via multispectral imaging          下载免费PDF全文

Gerald N. De La Fuente  Jens Michael Carstensen  Michael A. Edberg  Thomas Lü bberstedt 《Plant Breeding》2017,136(1):50-60

The use of doubled haploids (DHs) in maize has become ubiquitous in maize breeding programmes as it allows breeders to go from cross to evaluation in as little as 2 years. Two important aspects of the in vivo DH system used in maize are as follows: (i) the identification of haploid progeny and (ii) doubling of the haploid genome to produce fertile inbred lines. This study is focused on the first step. Currently, identification of maize haploid progeny is performed manually using the R1‐nj seed colour marker. This is a labour‐intensive and time‐consuming process; a method for automated sorting of haploids would increase the efficiency of DH line development. In this study, six inbred lines were crossed with the maternal haploid inducer ‘RWS/RWK‐76’ and a sample of seed was sorted manually for each line. Using the VideometerLab 3 system, spectral imaging techniques were applied to discriminate between haploids and hybrids. Using DNA markers to confirm the haploid/diploid state of the tested seed, for the majority of genotypes haploid identification was possible with over 50% accuracy.  相似文献   

Dietary Elements and Quality Parameters of 34 Old and Eight Commercial Apple Cultivars Grown at the same Site in South Tyrol,Italy     

Sara Agnolet  Flavio Ciesa  Evelyn Soini  Anna Cassar  Aldo Matteazzi  Walter Guerra  Peter Robatscher  Alberto Storti  Sanja Baric  Josef Dalla Via  Michael Oberhuber 《Erwerbs-Obstbau》2017,59(3):171-183

Apple is one of the most widely produced and consumed fruits worldwide and hence, complete data of apple composition are important for human diet. Currently, a limited number of cultivars dominate the market, while many others, with a potentially higher nutritional value, are neglected by consumers. The present work reports the content of the dietary elements potassium (K), phosphorus (P), calcium (Ca) and magnesium (Mg) as well as the content of the macroelement nitrogen (N) of 34 old cultivars grown at the same site under identical conditions in South Tyrol, Italy. Their elemental composition was assessed along with quality parameters such as fruit weight, firmness, and soluble solid content and total acidity at harvest and post storage. For selected cultivars the measurements were performed over two or even three different harvest years. Comparison with eight commercial cultivars chosen to represent the fruit currently dominating the market was performed.Besides offering a valuable insight in the variation of dietary elements among old and commercial apple cultivars in up to three harvest years, this study, that complements current nutritional databases, recommends several old cultivars with high content of dietary elements for further study and eventual re-introduction in niche markets.  相似文献   

Increased Postharvest Life of TomLox B Silenced Mutants of Tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>) Var. TA234     

Elizabeth León-García  Gilber Vela-Gutiérrez  Oscar A. Del Ángel-Coronel  Cristobal Torres-Palacios  Javier De La Cruz-Medina  Miguel A. Gómez-Lim  Hugo Sergio García 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(4):380-387

A healthy lifestyle includes fruits and vegetables consumption. Tomato is one of the most consumed vegetables, although it is susceptible to physical damage through postharvest handling, thus leading to important losses. Softening is an important variable during tomato ripening; excessive softening is undesirable and leads to postharvest losses. TomloxB plays an important role in ripening, mainly in the loss of cellular integrity caused by fatty acids released from the lipid matrix of membranes that initiate oxidative deterioration, which is in turn carried into senescence. In order to increase postharvest life, we produced transgenic tomato plants via Rhizobium radiobacter with tomato lipoxygenase B (TomloxB) antisense constructs under control of the cauliflower mosaic virus (CaMV) 35S promoter. Lipoxygenase activity and firmness were measured in tomato fruit and the fatty acids profile was determined. Transgenic fruits were maintained for 40 days at room temperature in optimal conditions, whereas wild type fruits remained in similar conditions for only six days. Firmness in pink and red stages was significantly lower in wild type fruits than in two transgenic lines. Linolenic acid was the most important fatty acid consumed by lipoxygenase in both turning and pink stages of ripening. Lipoxygenase activity was smaller in transformed fruits in comparison with the wild type. These results suggest that silencing the TomloxB gene promoted significant changes in the physiology of transformed tomatoes, being the increase in postharvest life the most important.  相似文献   

Biological control of the charcoal root rot fungus Macrophomina phaseolina on slash pine seedlings by a hyperparasite     

R.E. De La Cruz  D.H. Hubbell 《Soil biology & biochemistry》1975,7(1):25-30

Macrophomina phaseolina. the cause of damping-off and charcoal root rot disease on slash pine seedlings (Pinus elliottii Engelm var. elliottii), was antagonized by an unidentified basidiomycete species under laboratory and nursery conditions. Aseptically-grown slash pine seedlings died 3 days after inoculation with M. phaseolina, whereas seedlings inoculated with the basidiomycete sp., or basidiomycete sp. plus M. phaseolina, and uninoculated controls were alive after 6 months. In nursery studies, survival of slash pine seedlings in plots inoculated with M. phaseolina was significantly lower (57 per cent) than survival resulting from inoculations with the basidiomycete sp. (90 per cent), or basidiomycete sp. plus M. phaseolina (84 per cent), and the uninoculated controls (81 per cent). Electron microscopy showed that the basidiomycete sp. is a hyperparasite on mycelia of M. phaseolina. Preliminary evidence indicates that the hyperparasite is not host-specific but will infect other fungal pathogens. Two ectomycorrhizal fungi were not parasitized by the basidiomycete.  相似文献   

Population structure of purple sea urchin <Emphasis Type="Italic">Strongylocentrotus purpuratus</Emphasis> along the Baja California peninsula     

Nadia C Olivares-Bañuelos  Luís M Enríquez-Paredes  Lydia B Ladah  Jorge De La Rosa-Vélez 《Fisheries Science》2008,74(4):804-812

Abstract:   Purple sea urchin Strongylocentrotus purpuratus is fished from British Columbia, Canada to Punta Baja, Mexico. The North American population has been divided into northern and southern fishery stocks at the break of Point Conception, but little is known about its southernmost distribution along the Mexican Pacific coast of the Baja California peninsula. In this study purple sea urchin populations in six sites along the Baja California peninsula were analyzed using mitochondrial deoxyribonucleic acid restriction fragment length polymorphism (mtDNA RFLP). A homogeneous distribution of three common haplotypes among all sites was observed. A significant F _ST value, however, indicated genetic structure mainly due to the haplotype array in San Miguel, Isla Todos Santos and Punta Baja sites, which were characterized by having high haplotype diversity and several unique haplotypes. Homogeneous distribution of haplotypes along the peninsula could have been influenced by the unidirectional California Current system, flowing north to south. Unique haplotypes in Punta Baja and the structure found could be the result of local oceanographic features specific to this major upwelling zone. It may be necessary to consider the Punta Baja populations individually when managing the purple sea urchin fishery in Baja California, as they show signs of being a unique stock.  相似文献   

Early life history of the black anglerfish Lophius budegassa Spinola, 1807 in the Mediterranean Sea using otolith microstructure     

Mario La Mesa  Francesca De Rossi 《Fisheries Research》2008,93(1-2):234-239

The early life history of the black anglerfish, Lophius budegassa was investigated by otolith (lapilli) increment analysis. Samples of demersal juvenile L. budegassa ranging from 54 to 196 mm total length were collected during bottom trawl surveys in the central Adriatic Sea. By counting increments presumed to be deposited daily in the lapillar otoliths, 88 specimens of L. budegassa were successfully aged. Age estimates of juveniles ranged between 79 and 204 days, indicating that probably the pelagic phase of this species is relatively short and settlement occurs at less than 3 months of life. The analysis of check marks in the core area of lapilli enabled us to determine the period of endogenous feeding, which would last between 15 and 24 days after hatching. Back-calculated hatching dates and, consequently, the spawning season of L. budegassa in the Adriatic Sea was spread over a long period, lasting at least from February to June. The length at age relationship gave an estimate of mean growth rate of approximately 0.8–1.02 mm/day, indicating a faster growth rate of 0+ juveniles L. budegassa than previously thought. The implications of these findings on age estimates discrepancies between previous ageing studies on L. budegassa carried out using different calcified structure (sagittae or illicia) are discussed.  相似文献   

同时检测两种对虾病毒和4种弧菌的同步PCR方法的建立   总被引：3，自引：1，他引：2  

许拉  黄使  戈蕾  杨冰 《海洋水产研究》2008,29(4)

通过检索、多重比对、分析和筛选GenBank中对虾白斑综合征病毒(WSSV)、传染性皮下和造血器官坏死病毒(IHHNV)、副溶血孤菌、创伤弧菌、哈维氏弧菌和溶藻胶弧菌的基因序列,设计了10对特异性引物,以已知毒株和菌株的DNA为模板进行PCR,均能扩增出与实验设计相符合的DNA片段,对PCR扩增条件进行优化,建立了可同时检测鉴别WSSV、IHHNV、副溶血弧菌、创伤弧菌、哈维氏弧菌和溶藻胶弧菌,并且能同时区分WSSV不同地理毒株的同步PCR方法.研究结果表明,该方法检测特异性好,检测通量大,适合于对虾多种病原的同时检测.  相似文献   

浑善达克沙地景观格局变化研究   总被引：13，自引：5，他引：8  

王牧兰  包玉海  阿拉腾图雅  秦树晖 《干旱区资源与环境》2007,21(5):121-125

在遥感和GIS技术的支持下,通过采用转换矩阵和斑块伸长指数、破碎度指数、多样性指数、优势度指数、均匀度指数等景观指数分析了80年代末期到2000年浑善达克沙地景观动态变化,结果显示:①景观要素类型尺度上,研究区草原景观和固定沙丘景观面积明显缩小,半固定沙丘景观和流动沙地景观向外扩展,反映出整个沙地向荒漠化方向发展的趋势;②景观尺度上,斑块伸长指数有所下降,破碎度变大,反映出人类活动对景观的干预作用不断增强;景观多样性指数和均匀度指数减小,优势度指数增加,表明景观的组成趋向简单,主要景观对区域景观变化起到主导作用,景观中的支配能力和影响力在增强。  相似文献   

Temporal changes in the fish community structure of a small subtropical spring lake: Decadal and seasonal analysis     

Arely Ramírez-García  Omar Domínguez-Domínguez  Eugenia López-López  Rodrigo Moncayo-Estrada  José De La Cruz-Agüero 《Ecology of Freshwater Fish》2023,32(1):53-63

In spring lakes, which have homogeneous environmental characteristics, it is expected that there will be no significant changes in the composition and structure of communities over time, and fluctuations will generally be related to the ecological attributes of the species. We studied the fish community in a small subtropical spring lake, Lake Zacapu, for two different decades to analyse its structural characteristics. Sampling was performed every 3 months at four sites from January to October 1995 and from May 2019 to May 2020. We determined the temporal variation (seasonal and decadal) in the fish community structure with respect to composition, abundance, diversity and dominance. We evaluated the association between species and water quality. Our results showed spatial homogeneity in most physicochemical variables that remained in the same range across decades, although some nutrients (NO₃) recently increased. All species identified in the early samples were present in the recent surveys (eleven native and two nonnative species), indicating that the fish community composition had significant qualitative stability. However, the dominant littoral cyprinid in 1995 was replaced by the more limnetic atherinopsid in 2019–2020, and the diversity and abundance of sensitive fish decreased in recent samplings. Consequently, the current status of critically endangered species is supported for some restricted and microendemic fish. The changes in the community structure attributes, which show a tendency for reduction in native species, emphasise the need to implement efforts to conserve freshwater fish diversity in small spring lakes.  相似文献