Effect of Placement and Dose of Phosphatic Fertilizers on Onion

ABSTRACT

An experiment was conducted with six doses of phosphorus (P) and three placements to judge their effects on yield under gangetic alluvial soil. Univariate analysis of variance revealed that 60 kg ha^?1 P in combination with placement at 5 cm are the best with respect to different vegetative ant yield characters. Correlation and path analysis revealed that yield has got significant negative correlation with leaf dry weight. A direct negative effect of fresh weights of leaves was also evident from the path coefficient analysis. Multivariate cluster analysis following complete linkage using Euclidean distance by forming dendrogram could identify four clusters taking all the characters together. The treatment combinations T5 (2.5 cm, 60 kg ha^?1), T11 (5.0 cm, 60 kg ha^?1), T17 (7.5 cm, 60 kg ha^?1) along with T10 (5.0 cm, 45 kg ha^?1) are found to be the best lot of treatments for growth and yield of onion.     

甜菜套种毛葱丰产栽培技术

甜菜套种毛葱丰产栽培技术打破了传统的甜菜单一种植模式,根据毛葱与甜菜共生期短,在同一地块上将甜菜与毛葱进行套种,实现了优势互补、效益双赢的目的,提高了单位土地利用率,对推动种植业结构调整,起到了重要作用。     

大葱不同类型品种主要营养成分分析

本试验对26个中国棒状大葱、8个中国鸡腿大葱、3个中国分蘖大葱和3个日本大葱品种进行了品质测定。结果表明:鸡腿大葱的含糖量和丙酮酸含量均较高,生食熟食风味均较佳;日本大葱的含糖量较低,丙酮酸含量较高,适宜熟食;分蘖大葱的含糖量高,干物质、蛋白质、维生素C含量均较高,丙酮酸含量低,是生食大葱的最佳选择类型;棒状大葱粗纤维含量少、游离氨基酸含量较高,生熟食皆宜。同一类型不同品种之间,营养品质差别较大,每个类型都有营养品质较高的品种。     

固相微萃取-气相色谱-质谱法分析大葱挥发性成分

采用固相微萃取法(SPME)提取大葱中的挥发性成分,并用气相色谱-质谱联用仪分析其化学组成。结果表明,挥发性物质中主要成分为硫化物,3个大葱品种的硫化合物含量依次为黑310(72.6%)、气煞风(59.85%)和陕西鸡腿(50.97%)。3个大葱品种中的含硫化合物,一硫化合物主要以3,4-二甲基噻吩为主,二硫化合物主要以1-甲乙基丙基二硫醚为主,三硫化合物主要以二丙基三硫醚为主。     

南疆地区棉田棉蓟马种群数量动态研究

2002～2004年研究了南疆地区棉田棉蓟马的种群动态及棉花品种的影响.结果表明和以前相比棉蓟马依然是南疆棉花的重要害虫,2002、2003和2004年棉田棉蓟马日最高密度分别为5 328、3 033和3 383头/百株.对转基因抗虫棉GK19(表达Cry1A杀虫蛋白)、SGK321(表达Cry1A+CpTI杀虫蛋白)和普通棉花泗棉3号、石远321的研究表明棉蓟马在不同品种上的季节性数量动态没有显著差异.     

洋葱AcSCL4的克隆及其功能分析

【目的】初步探讨AcSCL4在洋葱成花中的功能,为解析洋葱成花分子调控机制提供理论基础。【方法】以长日生态型洋葱品系SB2为试验材料,根据已有的洋葱转录组数据,通过qRT-PCR筛选目的基因AcSCL4后进行基因克隆,并对其进行生物信息学分析;构建AcSCL4基因的过表达载体pB221-3300-AcSCL4并转化农杆菌,采用花序浸染法浸染拟南芥,并对T₃代纯系转基因植株进行表型分析和开花相关基因表达量分析。【结果】洋葱AcSCL4基因CDS长1 515 bp,编码504个氨基酸;AcSCL4蛋白N端高度变异,C端有GRAS结构域。聚类分析发现,AcSCL4与石刁柏和棉花的SCL4蛋白亲缘关系较近。与野生型拟南芥相比,AcSCL4过表达植株表现晚花表型。荧光定量PCR结果表明,与野生型拟南芥相比,AcSCL4过表达植株开花调控基因CO和FT的表达量极显著下降。【结论】AcSCL4通过调控CO及FT基因表达来抑制洋葱开花。     

洋葱种质资源数量性状的主成分分析和聚类分析

洋葱(Allium cepa L.)属百合科葱属二年生植物,是世界上主要蔬菜作物之一,也是中国主要的栽培和出口蔬菜.随着农业产业结构的调整,对洋葱优良品种的需求日益增加.     

Spread of levan-positive populations of <Emphasis Type="Italic">Pseudomonas savastanoi</Emphasis> pv. <Emphasis Type="Italic">savastanoi</Emphasis>, the causal agent of olive knot,in central Italy

Mixtures of wet vegetable wastes (Brassica, carrot or onion) and dry onion waste were composted at 50 °C for 7 days. The incorporation of the raw or composted vegetable waste mixtures into sandy loam, silt and peat soils reduced the viability of sclerotia of S. cepivorum in glasshouse pot bioassays. The reduction in viability was dependent on waste type, rate of incorporation, duration of exposure and soil type. Onion waste was the most effective waste type in reducing sclerotia viability in all three soils. The Brassica and carrot wastes were as effective as the onion waste in silt soil but less effective in sandy loam and peat soil. A 50% w/w incorporation rate of the wastes gave the largest reduction in viability, with an increase in reduction over time. Composted onion waste reduced sclerotia viability under glasshouse and field conditions although the effect was smaller in the field. Composted onion waste incorporated into soil at 50% w/w reduced the incidence of Allium white rot on onion seedlings in glasshouse pot tests. Incidence and control of the disease differed with soil type. The most consistent control was achieved in peat soil whereas no control was observed in silt soil. Incorporation of the waste 2 months prior to sowing or transplanting reduced seedling emergence in sandy loam soil and growth in all three soil types. The potential for field application of composted vegetable wastes as a sustainable method for control of Allium white rot and waste disposal is discussed.     

Fusarium oxysporum,F. proliferatum and F. redolens associated with basal rot of onion in Finland

In recent years in Finland, Fusarium infections in onions have increased, both in the field and in storage, and Fusarium species have taken the place of Botrytis as the worst pathogens causing post‐harvest rot of onion. To study Fusarium occurrence, samples were taken from onion sets, harvested onions and also from other plants grown in the onion fields. Isolates of five Fusarium species found in the survey were tested for pathogenicity on onion. Fusarium oxysporum was frequently found in onions and other plants, and, of the isolates tested, 31% caused disease symptoms and 15% caused growth stunting in onion seedlings. Fusarium proliferatum, a species previously not reported in Finland, was also identified. Over 50% of the diseased onion crop samples were infected with F. proliferatum, and all the F. proliferatum isolates tested were pathogenic to onion. Thus, compared to F. oxysporum, F. proliferatum seems to be more aggressive on onion. Also some of the F. redolens isolates were highly virulent, killing onion seedlings. Comparison of the translation elongation factor 1α gene sequences revealed that the majority of the aggressive isolates of F. oxysporum f. sp. cepae group together and are distinct from the other isolates. Incidence and relative proportions of the different Fusarium species differed between the sets and the mature bulbs. More research is required to determine to what extent Fusarium infections spoiling onions originate from infected onion sets rather than the field soil.     

大葱新品种郑研寒葱的选育

郑研寒葱是以日本宏太郎为母本，郑州长白条为父本，利用杂交育种技术，单株选择与系统选育相结合的方法培育
出的大葱新品种。株高95～120 cm，葱白长40～50 cm，横径2～3 cm，功能叶5～7 片，叶色浓绿，蜡粉多，单株鲜质量 0.25～0.65
kg，每 667 m² 产量 5 200 kg 以上；田间表现抗寒性强，抗紫斑病、霜霉病和锈病的能力强于对照章丘大葱，抗倒伏；葱白洁
白致密，辣味浓，有香味，风味佳；货架期长，耐贮藏。适合我国中原地区及西部、北部地区栽培。