温度和砷对不同品种水稻幼苗生长和砷吸收的影响

为明确温度和外源砷对水稻生长发育的影响,选取江苏地区常见的8个水稻品种为试验材料,通过添加不同浓度外源砷[0(As0)、0.5(As0.5) 和1 mg?L-1(As1)]和模拟不同温度[白天/夜晚分别为30 ℃/25 ℃（T0）和35 ℃/30 ℃（T1）],在人工气候箱内进行了发芽和苗期培养试验,并分析了8个品种水稻种子萌发、幼苗生长及砷含量状况。结果表明,外源砷对水稻的芽长和活力指数具有抑制作用,与对照（T0As0）相比,T0As1处理使不同品种水稻的芽长和活力指数分别降低13.69%~43.34%和28.14%~52.88%。 而温度对水稻种子萌发的影响与水稻品种有关。在T1处理下,盐两优1618的发芽率、芽长和活力指数均优于其他品种。温度和外源砷的共同作用显著降低了不同品种水稻的芽长（P<0.05）。与T0As0相比,T1As1使水稻芽长显著降低5.66%~43.34%。水稻根长和根系活力显著受到温度和外源砷的单一因素的影响。与T0As0相比,T0As1处理使水稻根系活力降低3.01%~58.21%。温度和外源砷的共同作用抑制了水稻根长和根系活力,其中T1As1使水稻根系活力显著降低53.80%~89.01%。不同品种水稻的苗高和根系活力在相同温度或外源砷处理下具有显著差异（P<0.05）,其中盐两优888的苗高和根系活力均处于较高水平。水稻茎叶砷含量在外源砷处理下显著增加,在增温处理下却降低。与单一的砷处理相比,温度和外源砷的共同作用降低了水稻茎叶的砷含量。综上可知,温度和外源砷影响水稻的生长及砷吸收,但水稻生长状况具有明显的品种间差异,其中盐两优888和盐两优1618在增温和外源砷共存条件下的种子萌发和生长状况优于其他水稻品种。     

1973-2022年广昌县气候变化趋势分析

基于1973至2022年广昌县域气温、降水量以及日照时数地面气象观测数据,通过线性气候倾向率分析、M-K突变检验分析以及滑动T检验分析方法,对过去50年广昌县域气候变化趋势进行分析。结果表明,近50年广昌县域年际平均气温呈显著性上升趋势,上升率为0.28℃/10a,且2001年为突变年;年际累计降水量呈非显著性下降趋势,下降率为-1.56mm/10a;年际总日照时数呈非显著性下降趋势,下降率为-35.49h/10a;因此今后赣中地区应注意加强高温干旱、暴雨洪涝等自然灾害的防御。     

1960-2017年长武县气候变化特征分析

本文利用长武县气象局1960—2017年近58年气温和降水的观测数据,运用线性回归、滑动平均、Mann-Kendall突变检验等研究方法,初步研究了长武县近58年气温和降水量变化特征。结果表明：在1960—2017年间,长武县年均温明显升高,增长速率为0.18℃/10 a,并在2004年发生趋势性突变;最冷月、最热月的平均气温都显著上升,增温速率分别为0.13℃/10 a和0.06℃/10 a;1960—2017年间,长武县年降水量明显下降,下降速率为4.31 mm/10 a,未发生趋势性突变;汛期降水量整体呈波动上升趋势,上升速率为3.65 mm/10 a,汛期降水量很大,约占年降水量的82%。     

Effect of environmental factors on fertility of Holstein–Friesian cattle in Japan

We investigated the environmental factors in Japan, including meteorological conditions, on the fertility of a European cattle breed, Holstein–Friesian, by examining conception rates in different regions. First artificial insemination and associated conception details were recorded for 69,952 Holstein female cattle. In general, meteorological conditions vary considerably according to latitude in Japanese islands. Conception rates were higher in the Northern (above 37°N) than the Southern (below 37°N) region (61.3% vs. 53.3%). All the factors analyzed in the statistical model, including insemination year, region, month, AI technician, service sire and interaction between region and month, had significant effects on the conception rate. In the Southern region, conception rates were lower in the summer months (average temperature, 27.8 °C, and maximum temperature, 32.3 °C). However, this seasonal decline was not observed in the Northern region (average temperature, 23.7 °C, and maximum temperature, 28.4 °C). Regression analysis of conception rate in relation to temperature showed highly significant negative regression coefficients (− 0.66 to − 0.63% per °C; p < 0.001) in the Southern region, but non-significant coefficients in the Northern region. Humidity had a minimal effect on conception rate in both regions. Our data collectively suggest that 37°N latitude is a threshold that affects Holstein–Friesian conception rates in Japan.     

家蚕温度敏感型致死基因ntl的遗传分析

从中系地方品种余杭７ 中发现１ 个新的温度敏感型致死基因ｎｔｌ,该基因的特点为：５ 龄期幼虫在平均温度为２３３ ℃时,幼虫生命率只有１０７％ ,而当５ 龄蚕在平均温度为２９４℃饲养时,幼虫生命率为９００ ％ 。经分析该性状受１ 对隐性基因所控制,可能是ｏｃ 油蚕的等位基因或与ｏｃ 油蚕基因存在着紧密的连锁关系,属于第５ 连锁群。     

Stress response of extensively reared young bulls being transported to growing-finishing farms under Spanish summer commercial conditions

To evaluate the effect of Spanish summer commercial journeys on the stress response of young bulls born and reared under extensive conditions, 2 replicates of a transport from an assembly centre to a growing-finishing farm were studied. Journeys lasted 27 h, involving a total of 62 young bulls. Variables under study included haematocrit, red blood cell count (RBC), total white blood cell count (WBC), differential WBC counts, serum haptoglobin (Hp), cortisol, glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), total protein, and albumin at loading, at the end of an intermediate market stop, and at the unloading. Before the beginning of the journey elevated WBC and neutrophil counts, and high Hp values were detected, reflecting high stress levels probably as a consequence of previous procedures associated with the grouping at the assembly centre. Some stress was also detected at the end of the market stop, with cortisol increasing from 6.5 to 12.6 ± 2.0 ng/mL (P < 0.001), although a change in Hp concentration was not observed. Neither CPK and LDH activities, related to muscular tissue damage, nor haematocrit and RBC count, related to dehydration revealed a significant effect of this first stage of the journey on the physical stress of the young bulls. Subsequent 13 h transport to the growing-finishing farm induced an increase in Hp levels from 0.48 to 0.78 ± 0.16 mg/mL (P < 0.001), reflecting an onset of the acute stress response, although cortisol levels immediately after the unloading were similar to those found before loading at the market, suggesting that calves got accustomed to transport. At the end of the journey some dehydration and physical stress were also detected. Overall, our study provides new information to the discussion of the effect of temperatures during cattle transport. Although an improvement in pre-transport conditions is essential if the welfare of assembled and transported cattle is to be improved, the stress-related alteration of cattle physiology under Spanish summer commercial transport conditions is similar to that observed under colder conditions.     

桑枝枯菌核病病原菌的生物学特性研究

从发病桑树上分离到桑枝枯菌核病病原菌的纯菌种 ,并对该菌的培养性状和生物学特性进行了调查和研究。结果表明 :桑枝枯菌核病病原菌适于在PDA培养基和桑叶汁培养基上生长 ,其生长温度范围为 8～ 30℃ ,最适生长温度为 2 0～ 2 5℃ ,生长pH值范围为 1～ 12 ,最适生长pH值为 5～ 8,菌丝与菌核的生长情况大致相同 ;菌核在适宜的温湿度条件下能够产生子囊盘和子囊孢子 ,子囊孢子椭圆形 ,大小 7～ 14 μm× 3～ 7μm。     

耐受自身代谢产物及耐二甲基亚砜红霉素高产菌株的选育

为提高红霉素发酵单位,考察了二甲基亚砜(DMSO)添加时间和体积分数对红霉素合成的影响,采用筛选自身代谢产物突变株的方法,将突变株进行常压室温等离子体(ARTP)诱变和耐受高浓度DMSO处理。结果显示,在36 h向发酵瓶中添加30000μg/m L红霉素,筛选得到化学效价比对照提高22.4%的菌株。DMSO最适添加时间为发酵48 h,最适添加剂量为0.2%,其可提高发酵单位10.1%。     

达日县十年间气温与降水的变化趋势及相关性分析

本文通过对达日县1995年至2004年10年来气温与降雨量的统计分析,探讨了达日县气温和降雨量的变化趋势及二者的相关性。结果表明:从1995年至2004年,平均气温逐渐升高,2003年达到最高值,与1995年相比平均气温升高了1.37℃;历年降雨量变化规律不明显,在全年尺度上降雨量的变化与气温变化基本一致,表现出明显的季节性变化规律。     

诱导滞育的温度和光照节律对家蚕滞育激素基因Dh表达的影响

滞育激素(DH)是导致家蚕滞育生理现象出现的关键因素。研究卵期不同温度和光照节律引起家蚕滞育激素基因Dh表达的变化,探讨温度和光照对家蚕滞育调控的机制。催青期25℃持续光照(25LL)条件下,蚕卵中Dh基因mRNA高水平稳定转录;而在15℃持续黑暗(15DD)条件下,蚕卵中只有痕迹量Dh基因mRNA存在;25LL或者20℃、光照与黑暗12h交替(20LD)条件下,胚胎发育至单眼着色后(有效积温2160℃.h以后)Dh基因mRNA转录水平显著上调,与此时期胚胎对诱导滞育的温度和光照节律更加敏感一致。从催青期开始整个世代的保护温度和光照节律,呈现高温25℃显著上调整个胚后时期Dh基因mRNA转录水平,光照上调蛹期与蛾期Dh基因mRNA转录水平,且高温的作用强于光照。5龄第3天幼虫的基因芯片表达谱显示,Dh基因mRNA转录水平存在显著的性别与组织差异,雌蚕多个组织中的Dh基因mRNA转录水平都显著低于雄蚕,卵巢中的Dh基因mRNA只有痕迹量。亲代卵的催青温度与光照节律决定子代卵的滞育性,也影响到Dh基因mRNA的转录水平;但子代卵内Dh基因mRNA转录水平高低不是蚕卵滞育与否的关键。推测家蚕Dh基因表达的性别差异及在早期蚕卵中表达特征与滞育性不一致的现象,可能与Dh基因的前体多肽翻译产物剪切有关。