Effect of aggregate size and soil water content on emergence of soybean (Glycine max, L. Merr.) and maize (Zea mays, L.)

Rapid wetting of irrigated soils often leads to slaking and slumping, and on drying a surface crust and hard-set conditions may occur. This results in reduced crop emergence unless the surface is kept moist. The effect of aggregate size and water content on the emergence of soybean and maize from an Entic chromustert (heavy cracking clay) was determined using pots of sieved aggregates with size ranges less than 1, 1–2, 2–5 and 5–15 mm at soil water contents of 15, 20 and 25 g (100 g)⁻¹. Unsieved soil was used as a control. Greatest emergence tended to occur from fine (1–2 mm) seedbeds compared with coarse (5–15 mm) seedbeds for both crops. A covered treatment, simulating a stubble mulch, resulted in greater emergence than an uncovered treatment for all water contents and aggregate sizes. Earlier emergence occurred from finer (less than 1 mm and 1–2 mm) seedbeds than from coarse (5–15 mm) seedbeds, and at the greatest water content used. Soil strength, measured with a shear vane, decreased with increasing water content and tended to be less on fine (1–2 mm) seedbeds compared with very fine (less than 1 mm) or coarse (5–15 mm) seedbeds. It is recommended that, for good emergence from this Entic chromustert, seedbeds be brought to a water content of 25 g (100 g)⁻¹ by capillary wetting to prevent hardsetting and consist of 1–2 or 2–5 mm aggregates for soybean and maize, respectively, and have a stubble mulch on the surface. This corresponds to an equivalent depth of water of 15 mm and 9 mm for soybean and maize, respectively, in the top 50 mm of the profile.     

用Stock6杂交诱导的单倍体鉴定方法初探

试验以Stock6杂交诱导种子为材料,对单倍体鉴定方法进行初步研究。结果表明,表型性状如子粒Navajo标记、紫色植株标记、株高都可用于鉴定单倍体,综合应用这些方法时株高鉴定最准确。子粒Navajo标记和紫色植株标记鉴定可淘汰掉大量杂交二倍体;在无紫色植株标记的绿色植株中,株高相对较矮的是单倍体,生长发育正常的植株可能是纯合二倍体或杂交二倍体,需进一步通过单倍体子代果穗子粒Navajo标记鉴定,所获子粒均无子粒Navajo标记的是纯合二倍体,有子粒Navajo标记的是杂交二倍体;细胞学鉴定直接验证了其它表型鉴别方法的鉴定准确性。总之,这些单倍体鉴定方法各有优缺点,综合应用它们可以提高单倍体鉴定效率,加快单倍体育种技术在玉米遗传育种中的应用。     

三种杨树树皮真菌群落的研究

对毛白杨、陕林4号杨、北京杨不同年龄枝条、树体空间层次的真菌种类、数量及季节动态作了分析，结果表明：三种杨树树皮真菌群落组成不同，链格孢属(Alternaria)、曲霉属(Aspergillus)、内脐蠕孢属(Drechslera)、毛壳属(Chaetomium)等为毛白杨上的优势菌种群；链格孢属、曲霉属、木霉属(Trichoderma)、青霉属(Penicillium)等为陕林4号杨的优势菌种群；链格孢属、曲霉属、盾壳霉属(Coniothyrium)、青霉属等为北京杨的优势菌种群。真菌种类及数量在树体空间层次的分布趋势是由上到下逐渐增多；真菌群落季节变化趋势为夏、秋季种类和数量稍高，春、冬季有所减少。     

数字图像处理在植物新品种鉴定中的应用

随着分子生物学和信息技术的发展,指纹图谱技术已成为品种鉴定的重要手段。本文从目前人工鉴定指纹图谱的方法出发,提出了利用计算机的图像处理技术来实现指纹图谱鉴定的方法以及实现技术。     

黑龙江省部分玉米杂交种的综合评价

玉米杂交种的综合评价是新品种选育、审定和推广的重要依据。以黑龙江省种植的部分玉米杂交种为试验材料,测定其产量（14%含水量）、籽粒含水量、容重、秃尖长、出籽率、轴粗/穗粗、百粒重和穗长8个性状,采用灰色关联度法对28个供试玉米杂交种的8个性状进行综合评价。结果表明,德美亚3号、先玉696和先玉335加权关联度排在前3位,综合表现好。     

Genetic Analysis of Chromosome 2D of Wheat

The Yugoslavian varieties ‘Novosadska Rana 1’ and ‘Sava’ are shown by monosomic comparisons to carry weak height promoters on chromosome 2D characteristic of the ‘Akakomugi’ gene for reduced height, Rht8. Reciprocal monosomic crosses between ‘Bersee’ and ‘Sava’ demonstrate ‘Sava’ chromosome 2D reduces height by about 16 cms, accelerates ear emergence by about 9 days and increases yield through increased grain number and grain size. Recombinant lines developed for chromosome 2D suggest that this chromosome in Mediterranean wheats carries three genes, Rht8, Ppd1 and Yr16, important to their adaptation. Rht8 and Ppd1, a gene for day length insensitivity together reduce height. Ppd1 and, to a minor degree, either yr16, the susceptible allele of a gene for adult plant resistance to yellow rust or a closely linked gene, accelerate time to flowering and thereby avoid desiccating Yugoslavian summer conditions. The same genes reduce spikelets numbers but this is offset by increased floret fertility producing an overall increase in the number of grains per ear. Ppd1 also by avoiding desiccating conditions increases gram size and together with either yr16 or the closely linked fertility gene increases ear and plant yields.     

大别山油茶4个优良品种光合作用特性

2010年9月20测量了大别山系列油茶优良品种1号、2号、3号及4号光合特性的日变化,结果表明:(1)4个油茶品种的Pn日变化均为单峰曲线,大别山1号和4号的峰值出现在12:00,2号和3号峰值出现在11:00,不存在光合午休现象;(2)4个油茶品种Tr日变化均为单峰曲线,但峰值出现时间不一致;(3)eWUE的日变化总体呈逐渐下降的趋势,最高值出现在8:00,到16:00以后有小幅上升,随后迅速下降;(4)从4个油茶的光补偿点(ELCP)和光饱和点(ELSP)来看,均为耐阴喜光的阳性树种。     

木瓜属植物新品种特异性、一致性和稳定性(DUS)测试指南的研制

遵循国际植物新品种保护联盟及我国的相关规定,分析木瓜属植物品种的性状变异规律及其稳定性和相关性(DUS),探讨标准品种和测试性状的选择。筛选31个测试性状和12个标准品种用于新品种DUS测试;其中,质量性状10个、数量性状6个、假质量性状15个,*号性状24个、非*号性状7个,每个性状的表达状态给以相应的代码。*号性状主要有株型、花色、花径、重瓣性、果实形状及果皮皱缩状况等。提出木瓜属植物新品种的特异性、一致性、稳定性判别标准。     

湖北省林业植物新品种保护现状及对策

植物新品种权是知识产权的一部分,我国从法律层面保护植物育种者的权益,鼓励在新品种培育上的投入和研发.本文综述我国林业植物新品种保护制度的历史演变、授权情况和湖北省林业植物授权品种的概况,分析湖北省新品种保护存在的问题,并提出了对策和建议.     

不同种肥施用水平对大果沙棘苗期生长的影响

在西宁地区采用裂区设计将不同品种沙棘种植于不同种肥用量下进行实验结果表明：中华沙棘在其株高、根长、根茎、干重四项指标的测定中均高于向阳、楚伊两个大果沙棘品种。在300 kg/hm^2的施肥水平下,大果沙棘的苗期株高、根长、根茎、干重生长量最大。品种和不同磷酸二氨的施肥量的互作显著,中华沙棘在低肥条件下的生长量大,在高肥条件下向阳、楚伊的生长量大。