水稻不育系先红A紫叶性状的遗传行为及其应用前景

用新育成的带紫叶色标记的水稻不育系先红A(B)为材料,分别与不同类型的绿叶籼稻、粳稻品种杂交,研究其紫叶性状的遗传行为。结果表明,先红A(B)的紫叶性状由1对紫叶基因控制,一般正常绿叶水稻品种带有1～2对抑制基因可调控该紫叶基因的表达。先红A(B)的紫叶性状及其杂种F1绿叶性状表达稳定,不受光温环境及栽培条件的影响。先红A的紫叶性状是杂交稻种子鉴纯和制种防杂保纯的一种理想标记。先红A配制杂种,可筛选出株叶型好且优势强的组合,显示出良好的应用前景。     

天水市不透水表面提取及时空变化分析

不透水表面的发展是城市化进程的重要体现。采用天水市1996、2001、2007年3个时期的LandsatTM遥感影像,使用面向对象的方法,通过构建具有较强适应性的比值不透水表面指数RISI,结合植被指数NDVI、水体指数MNDWl等,从遥感影像中提取了不透水面信息,并对其时空发展变化和驱动力进行了分析。结果表明,天水市不透水表面增加明显,与该地区的自然地理格局和经济社会发展密切相关。     

远距离台风暴雨研究综述

归纳了近几十年来对此类暴雨的研究成果,总结了其气候特征,主要从中纬系统的相互作用、地形作用、重力惯性波、中尺度系统综述了其形成的机理。     

1961—2015年安徽省春季日照时数变化特征

为了研究安徽省春季日照时数变化特征,为合理安排农事提供依据,使用近55a(1961—2015年)安徽省春季78个气象台站逐日日照时数资料,利用相关分析、线性趋势分析、Mann-Kendall以及Morlet小波变换分析等方法对安徽省春季日照时数进行了分析,结果表明：安徽省春季多年平均日照时数在381.55—626.75h之间,呈北多南少的空间分布特征;春季日照时数年际变化明显,日照时数最多年为最少年的1.7倍。在近55a中,日照时数整体上呈现出先减后增的变化趋势;在各个年代中日照时数周期存在差异;在21世纪初日照时数由减少转为增加,属于突变现象;安徽省春季日照时数变化趋势存在明显的空间差异,淮北主要以减少趋势为主,江淮之间增减参半,沿江江南则主要表现为增加趋势。     

Effect of a short duration feed withdrawal followed by full feeding on marbling fat in beef carcasses

The effect of feed withdrawal for 48 h, prior to initiation of the finishing (fattening) period (75 d) on carcass marbling fat was studied in 120 European × British cross-bred heifers with an average weight of 585 ± 39 kg. Heifers were randomized in a 2 × 2 factorial design experiment with two dietary management treatments, where half the heifers were provided the feed components of steam rolled barley and barley silage either free choice or as a total mixed ration (TMR) containing 87% steam rolled barley and 13% barley silage with ad libitum vitamins and minerals via salt blocks for all animals. Within each dietary management treatment, 30 heifers were denied feed (water was available) for 48 h prior to the two week adaptation to the high grain diet preceding the 75 d finishing period. At the end of the 48 h feed denial blood samples were collected from the jugular vein prior to feeding for determination of glucose and insulin concentrations, which indicated that 48 h feed withdrawal consistently decreased (P = 0.0001) plasma concentrations of both glucose and insulin but the ratios of the concentrations of glucose to insulin were not affected. At slaughter samples of subcutaneous fat from the brisket (BF) and skirt muscle (pars costalis diaphragmatis; PCD) were procured for determination of chemical fat content, fat dissected from the muscle and for enumeration of adipocytes, less than 35 μm in diameter and to determine the average cell size in the dissected fat and from the BF by flow-cytometry of adipocytes fixed in osmium tetroxide. The carcass characteristics were also obtained. Although no differences due feed withdrawal for 48 h were evident for carcass weight, percent lean (saleable) meat yield, rib eye area, average fat cover, fat content of PCD or BF, the US marbling score was increased (P = 0.048) and the amount of dissected fat from the muscle tended to be higher (P = 0.107), thus 81% of the carcasses graded “US Choice” or “Canada AAA,” or displayed at least a “small” amount of intramuscular fat as compared (P = 0.0807) to 68% of the heifers not denied feed. Based on more than three years of weekly prices of carcasses that graded “Canada AAA” and “Canada AA,” these experimental results suggested that the expected price of a finished heifer could increase by $4.61 Canadian if a 48 h feed withdrawal was imposed prior to initiation of the finishing phase. Although significant differences in adipocyte numbers due to a single time 48 h feed withdrawal prior to initiation of the finishing phase were not detected, the carcass quality factors were affected leading to an odds ratio of 1.84 times in favour of cattle carcasses to grade “Canada AAA” than if fed continuously.     

江苏句容地区土壤中多环芳烃的分布特征及来源

以江苏句容地区20个点位的土壤样品为试材,分析了该地区土壤中16种优控多环芳烃（PAHs）污染物的含量特征及污染水平。结果表明,该地区土壤中PAHs总量为5.15～375.19μg/kg,其中Flt含量最高,与西藏、北京、天津、汕头等地区相比,PAHs污染处于中等水平;土壤中PAHs以3环PAHs为主,主要单个污染物为Flt、Phe和Cry;秸秆焚烧、薪柴烹饪、燃煤取暖等人类活动是该地区多环芳烃主要来源因素,个别采样点因靠近交通干道,其多环芳烃主要来源于汽车尾气。     

不均衡种植方式对谷子农艺性状及光合参数的影响

为了探究不均衡种植方式对谷子产量的影响,以农大8号和农大10号为试材,采用裂区设计,以品种为主区,不均衡种植方式为副区,测定不均衡种植方式下的谷子主要农艺性状、光合参数等指标。结果表明,与等行距种植(30cm+30cm)和宽幅种植(60cm+15cm+15cm)相比,宽窄行种植(宽行40cm+窄行20cm)的谷子株高、茎粗、叶绿素、叶面积及光合速率、气孔导度等显著提高,胞间CO2浓度有所下降,产量显著提高,等行距种植与宽幅种植之间无显著差异;与等行距相比,宽幅种植的穗重、千粒重显著提高。本研究结果为谷子高产栽培提供了技术指导。     

围栏封育对红松洼自然保护区草原植物群落特征及多样性的影响

以红松洼自然保护区草原植物群落为研究对象,采用样方法对研究区2012—2016年连续5年围栏封育植被进行了调查分析。结果表明:围封5年的植物群落优势种并未发生明显更替变化,但随围封年限增加,围栏内优势种及其他物种的重要值发生改变,其中地榆(Sanguisorba officinalis)、裂叶蒿(Artemisia tanacetifolia)重要值明显增加,细叶苔草(Carex rigescens)降低最多。围栏封育使植物群落的高度、盖度、生物量均明显增加(p0.05)。从不同经济类群分析,其优良牧草类、药用类植物比例增加,而杂类草比例相对下降。围封5年,植物群落丰富度指数、物种多样性指数、均匀度指数显著增加(p0.05)。     

近50年青州市气温变化特征分析

利用1961—2010年青州市气温观测资料,采用线性回归、M-K突变检验等方法,分析近50年来该市年、季、月平均气温以及平均最高、最低气温的变化特征。结果表明,1961—2010年青州市平均气温呈上升趋势,其气候变化倾向率为0.35℃/10 a,近50年年平均气温上升约1.8℃;四季平均气温均呈增温趋势,其中冬季气温增温趋势最为明显,增温率大小依次为冬季、春季、秋季、夏季;年平均气温的突变年是1989年。近50年青州市平均最高气温20世纪60年代为一个高值区,70年代为近50年来最低值,自70年代以来气温逐渐回升,在90年代达到最高值;平均最低气温20世纪60年代为最冷期,自70年代以来气温快速回升,在90年代达到最高值。     

NaCl胁迫对不同染色体倍性西瓜种子发芽特性的影响

用盐水浸种催芽方法,通过对蜜枚西瓜的二倍体、三倍体、四倍体在不同浓度NaCl胁迫下种子的发芽率、胚轴长度以及鲜重、发芽指数、活力指数等指标的测定,在30~90mmol/L低浓度下,倍性之间相对发芽率没有明显差异;在120 mmol/L以上浓度时,不同倍性之间差异明显,在150mmol/L NaCl胁迫下,其M4x、M3x、M2x相对发芽率分别为77.8%、63.4%、30.6%,180mmol/L时分别为37.8%、31.7%、0,在210mmol/L时,M4x和M3x仍然有种子萌发,耐盐性为M4x＞M3x＞M2x。