从不同源杂交种选育玉米二环系的配合力研究

在玉米育种中以GCA,SCA为指标选择玉米二环系的源杂交种作为基础材料来选系,从而选择优良的玉米自交系和杂交组合,本研究结果表明,这种选育玉米自交系的方法是可行和有效的.     

春早熟甘蓝新品种‘张甘40’

‘张甘40’是以雄性不育系‘M0105-7’(保持系‘8513-1-2’)为母本,以‘F07013-5’为父本配制而成的甘蓝新品种,成熟期60 d左右。开展度56.08 cm,外叶9~11片,蜡质轻,单球质量1.6~2.4 kg,叶球高17.0 cm,叶球宽14.0 cm,产量75 000~85 500 kg·hm~(-2)。圆球,中心柱7.0 cm,成熟球外包绿叶2~3层,根茎高3.0 cm。口感脆甜。耐裂球,耐抽苔,适合冀北高寒地区春秋两季露地栽培。     

Numerical simulation of deformations and forces of a floating fish cage collar in waves

The dynamic behavior of a fish cage collar in waves was investigated using a numerical model based on the finite element method. The floating collar and mooring system were divided into a series of line segments modeled by straight massless model segments with a node at each end. To verify the validity of the numerical model, research data from other authors were cited and compared with the simulated results, the comparison of results showed a good agreement. The numerical model was then applied to a dynamic simulation of a floating cage collar in waves to analyze its elastic deformation and mooring line tension. The simulated results indicated that the greatest deformation of the collar taken place in the position of the mooring line connection point when incident waves were in the same direction. An increase in the length of mooring line would help to decrease the mooring line tension of the collar. Furthermore, the effects of collar dimension, including collar circumference, pipe diameter in cross-section, and pipe thickness, on the dynamic behavior of the floating collar were discussed. The results of this study provided a better understanding of the dynamic behavior of the fish cage collar.     

浅谈二种生活用具在棉花自交与杂交中的应用

棉花在栽培过程中,为了获得好性状的棉珠,利用自交与杂交技术进行育种,本文论述小铁夹和吸汽水管方法的精髓及注意事项。     

Comparison of dietary essential amino acid requirements determined from group‐housed versus individually‐housed juvenile bluegill,Lepomis macrochirus

Two 60‐day experiments were conducted sequentially to determine (i) lysine requirement of juvenile bluegill, Lepomis macrochirus based on the dose–response method, (ii) requirements for other essential amino acids (EAAs) using whole‐body amino acid profile and (iii) whether differences in growth rates of group‐housed versus individually‐housed bluegills lead to different lysine requirement levels because of the presence and absence, respectively, of social hierarchies. Seven, semi‐purified, experimental diets (isonitrogenous, isocaloric) were prepared to contain graded levels of digestible lysine (10–31 g kg⁻¹). Experiment‐1 involved group‐housed bluegills (approximately 27 g, n = 10 fish/chamber, 4 chambers/diet) whereas experiment‐2 involved individually‐housed bluegills (approximately 30 g, n = 1 fish/chamber, 14 chambers/diet). Fish were fed twice daily to apparent satiation. Bluegill growth responses in both experiments generally improved (P < 0.05, anova ) with increasing dietary lysine levels from 10 to 16 g kg⁻¹, and then levelled off with further increase in lysine level (P > 0.05). Optimal dietary lysine level (digestible basis) was estimated to be 15 g kg⁻¹ based on broken‐line regression analyses of relative growth rate and feed conversion ratio with no differences being observed between the two rearing methods. Determined dietary requirement levels for other EAAs ranged from 2.4 g kg⁻¹ (tryptophan) to 15.3 g kg⁻¹ (leucine).     

聚合7OE亚基1B/1R易位系材料的创制及其品质研究

为提高小麦1B/1R易位系的加工品质，本研究选用高分子量麦谷蛋白亚基组成为1/7+9/2+12的小麦1B/1R易位系品种科农199为母本，与高分子量麦谷蛋白亚基组成为1/7^OE+8^*/5+10的强筋春小麦品种津强6号杂交，利用分子标记在F₄代株系中筛选到一个7^OE亚基基因与黑麦碱基因聚合在同一条染色体上的1B/1R易位系材料。PCR结果显示，该聚合材料和非聚合材料在Glu-A1和Glu-D1位点没有差异。在温室种植条件下，对这些聚合材料和非聚合材料及其亲本进行麦谷蛋白溶胀指数(SIG)测定，结果表明，与1B/1R易位系亲本科农199比较，聚合5+10优质亚基后SIG值显著提高，聚合7^OE优质亚基后，SIG值进一步显著提高，部分聚合材料达到了强筋亲本津强6号的水平。将聚合材料和非聚合材料及其亲本种植于大田，发现聚合5+10和7^OE优质亚基株系的乳酸-SDS溶剂保持力(LA-SDS SRC)和SDS沉降值均显著高于只聚合5+10优质亚基的株系，但未达到强筋亲本...     

不同种质玉米自交系种子萌发的干旱胁迫研究

种子萌发期被认为是作物生长的关键时期,也是衡量作物耐旱性强弱的重要时期。为了明确不同玉米自交系的耐旱性,本研究采用聚乙二醇(PEG)模拟干旱条件,对254份不同种质玉米自交系进行种子萌发期处理。通过检测发芽指数、发芽率、根数、根鲜重、根干重、茎鲜重、茎干重、根长、苗高等种子发芽性状,以其相对值为指标,鉴定不同自交系种子萌发期的耐旱性。结果表明,在5%PEG6000浓度胁迫时,种子萌发程度低,当PEG浓度为10%时,种子萌发受抑制程度较高；各性状相对指标都与品种综合抗旱能力呈显著或极显著正相关；不同自交系的耐旱性存在较大差异,通过隶属函数法结合抗旱分级标准筛选出99份中等耐旱材料。因此,该方法可以作为一种简单的玉米自交系萌发期耐旱性鉴定方法。     

籼型耐高温三系不育系巨风2A的选育

以优质常规材料9526为母本,宜陵1B为父本杂交,优选后代与宜陵1A回交而育成的早熟中籼型三系不育系巨风2A,具有耐高温、高异交率、高配合力,所配杂交稻熟色好等优点,应用前景广泛。2014年8月通过了湖北省农作物品种审定委员会的现场鉴定,2015年通过了湖北省审定。     

线损分析在轨道交通企业能源管理中的应用

轨道交通的不断发展需要更多的电能,但当今能源日趋紧张,对节能降损必须予以足够的重视.所以轨道交通企业须在供电用电管理中加强线损的分析和预测,从供电设计、规划、管理等方面实施降低线损管理,使企业节能降耗并有效提高经济效益.