花粉在植物遗传研究中的应用

高等植物的花粉是一种理想的植物遗传转化材料。将花粉作为外源DNA的受体或媒介进行转基因研究,已成为现代植物遗传转化技术中的重要部分。小孢子花粉可以在植物体内自然发育为成熟花粉然后参与受精作用,或者经过小孢子培养进行孤雌生殖从而形成单倍体植抹,还可以在离体培养条件下使未成熟花粉发育成为可育花粉。笔者分别简要介绍了以上3种途径的研究现状、花粉培养方法以及在植物遗传转化中的应用,并通过对各方法优缺点的综合评价,为科研人员和育种工作者进行花发育机制研究、功能基因表达和作物遗传改良提供了一条新的思路。     

影响油菜游离小孢子培养再生因素的研究进展

游离小孢子培养已经成为油菜遗传育种和生物工程的重要内容。由于影响游离小孢子形态发生的因素较多，尤其是生长在大田环境下的植株，小孢子发育不一致，游离小孢子形态发生产生频率低，因此形态发生诱导率低仍然是限制该技术广泛应用的一个问题。为此，深入和全面了解影响小孢子形态发生能力及再生体系的各种因素，掌握这一领域的研究动态和今后发展的方向，有助于优化油菜小孢子的再生体系、促进油菜育种。本文总结了油菜游离小孢子形态发生的研究进展，并认为应用分子技术克服小孢子离体形态发生障碍有极大的发展潜力。     

芋花粉活力测定及最佳贮藏方法的选择

为确保芋杂交育种实验的有效开展,研究芋花粉活力测定和花粉贮藏的方法。实验结果表明,柱头稀释液培养法和培养基萌发法均能有效测定芋的花粉活力;芋花粉萌发的最佳培养基配方是:10 mg/L硼酸+0.01%无水氯化钙+5%蔗糖。芋花粉的寿命短,但不同芋品种的花粉寿命不同;芋花粉在15%空气湿度或-20℃干燥条件下可以贮藏相对较长的时间。     

椰枣花粉离体萌发及花粉贮藏方法分析

本研究以椰枣雄株花粉为材料,采用L9(34)正交设计法筛选最佳观察椰枣花粉萌发时间和适宜椰枣花粉离体萌发培养基;研究椰枣花粉干燥时间、贮藏温度和贮藏时间对花粉萌发率的影响。结果表明,椰枣花粉萌发最佳观察时间段为2～4 h;处理1培养基50 g/L蔗糖+0.1 g/L硼酸+0.05 g/L氯化钙效果最佳,其中3因素对椰枣花粉萌发影响大小依次为硼酸、蔗糖、氯化钙;花粉在35℃中干燥8 h最适宜贮藏;当贮藏时间为10～50 d时,常温贮藏的花粉萌发率低甚至无萌发的现象,低于4℃条件下贮藏花粉萌发率均保持较高,无显著差异;当在4℃条件下,10、20、30 d花粉萌发率均无显著差异,当在-20℃,-80℃条件下,10、20、30、40 d花粉萌发率均无显著差异,花粉均保持较高的萌发率,在低温贮藏中随着贮藏时间的延长花粉萌发率逐渐下降。本研究可为椰枣花粉活力检测和贮藏提供技术支撑,同时为今后在椰枣引种推广中的花粉贮藏和人工授粉提供科学依据和实践意义。     

番茄花药离体培养中低温预处理对小孢子发育的影响

为明确低温预处理对番茄花药离体培养过程中小孢子发育的影响，进行了番茄花药离体培养的低温预处理试验，试验结果表明：离体培养条件下，雄核发育存在三条途径，即B途径、A-V途径和A-G途径，以B途径为主；随着培养时间的增加，小孢子逐渐退化；对番茄花药离体培养进行低温预处理，可在一定程度上延缓番茄小孢子退化，提早雄核发育，并增加参与雄核发育小孢子的比率，但参与B-途径的小孢子比参与A-途径的增加得多。     

植物单倍体技术在林木育种中的应用研究

文章分析了单倍体技术及其在林木育种中应用的意义,提出了林木单倍体育种方式,研究了花药培养在林木育种中的应用,展望了林木单倍体育种前景,以供参考。     

两株抗香蕉枯萎病菌链霉菌固态发酵条件的优化及混合菌载体的选择

将具有抗香蕉枯萎病菌活性链霉菌通过固体发酵的优化,提高其菌丝生长以及孢子产量,并选择合适的吸附载体,为后期的香蕉枯萎病大田生物防治研究提供技术基础。采用单因子和4因子3水平正交试验法优化白刺链霉菌BWL15-4菌株及不吸水链霉菌BWL58菌株的固态法发酵培养基配方,通过单因子试验探讨了初始pH、接种量以及培养温度对2株菌生长情况的影响,并以孢子存活量多少确定了混合菌株的最适载体。BWL58优化后的固态发酵条件为：pH 7.0左右,接种量2%,发酵温度28℃,培养基配方为：无机盐水占大米重量的150%,黄豆粉占大米重量的5%,麸皮占大米重量的20%,沙土占大米重量的30%。BWL15-4优化后的固体发酵条件为：初始pH 6.3左右,接种量3%,发酵温度29.5℃。培养基配方为无机盐水占大米重量的130%,黄豆粉占大米重量的10%,麸皮占大米重量的20%,沙土占大米重量的20%。非耕作层土与混合菌以2:1的比例混合时,在常温下保存3个月后,孢子数只降低一个数量级。按照此优化条件进行固态发酵,白刺链霉菌BWL58菌株及不吸水链霉菌BWL15-4菌株孢子含量可分别达到1013 cfu/g和1012 cfu/g数量级以上。通过筛选得到了混合菌的最佳填料为非耕作层土。     

褪黑素测定方法及玉米、水稻种子中褪黑素含量的分析研究

褪黑素（melatonin,缩写MT）是一种吲哚类色胺（N-乙酰-5-甲氧基色胺）,MT被证实广泛存在于生物有机体中。本试验利用玉米、水稻种子作为材料,探索种子中MT含量的测定方法、并初步了解玉米和水稻种子中MT含量情况。结果表明：(1)用高效液相色谱法（HPLC）来检测种子中MT含量是可行的, 褪黑素在0.01～1.20mg/kg浓度范围内,其标准曲线的回归方程为Y＝643436X－2446.1,R2＝0.9998,平均回收率达94.11%;（2）玉米、水稻两种粮食作物种子中含有褪黑素成份,且不同种间、品种间MT含量差异很大。玉米品种MT平均含量为96.5PPb,变幅为0～2034PPb;水稻平均为16.0PPb,变幅为0～264PPb。     

‘Pasifika’ and ‘I‐Kiribati’ identity in Aotearoa New Zealand: ‘Dancing’ and ‘edge‐walking’ through multiple identities

This article explores the relationship between I‐Kiribati communities and the broader ‘imagined’ Pasifika community in Aotearoa New Zealand. It looks at the way a group of I‐Kiribati tertiary students experience identity within this context. Through the use of semi‐structured interviews and a discourse analysis, the study draws three main conclusions. First, that I‐Kiribati navigate multiple identities and are constantly negotiating these within different spaces. Although this contributes to uncertainties around identity, I‐Kiribati students also strategically enact identity to suit various contexts. Second, that Pasifika as a term tends to infer ‘Polynesian’ which in turn may marginalise I‐Kiribati identities within certain spaces, particularly in education settings that intend to support all Pacific identities. Yet, given such a narrow understanding of Pasifika, these efforts may counter that intention for those on the margins of, or outside the common usage of, the term Pasifika. Last, community plays a significant role in the formation of identities within minority groups, which is important for countering aspects of marginalisation experienced within broader pan‐ethnic labels such as Pasifika. Consequently, we argue that Pasifika as a label needs to better reflect inter‐Pacific diversity as well as the identity negotiations that Aotearoa New Zealand‐born Pacific peoples navigate.     

制冷贮藏温度对锦橙的影响

以锦橙为材料,研究不同制冷温度对贮藏效果和锦橙品质的影响。结果表明,温度明显影响着锦橙的腐烂率和褐斑病率,温度6～8℃下贮藏150d锦橙的腐烂率和褐斑病率最低,分别为5.40%和5.41%;温度是影响失质量率的重要因素,制冷贮藏的失质量率低于通风贮藏;温度是影响锦橙果实呼吸代谢的重要因素,果实的呼吸强度随温度的降低而明显降低;果实有机酸含量随温度降低而明显提高,总糖含量的变化规律与有机酸基本相同;低温贮藏也可降低VC、可溶性固形物的损耗;贮藏温度过高,病菌性腐烂率高,品质下降快,而温度过低则产生冷害型腐烂,果皮不能正常转色,认为锦橙长期贮藏的适宜温度为6～8℃。     

Deployment of cold tolerance loci from Oryza sativa ssp. Japonica cv. ‘Nipponbare’ in a high‐yielding Indica rice cultivar ‘93‐11’

Cold tolerance is a complex trait, and QTL pyramiding is required for rice breeding. In this study, a total of seven QTLs for cold tolerance in the Japonica rice variety ‘Nipponbare’ were identified in an F_2:3 population. A stably inherited major QTL, called qCTS11, was detected in the region adjacent to the centromere of chromosome 11. In a near‐isogenic line population, the QTL was further dissected into two linked loci, qCTS11.1 and qCTS11.2. Both of the homozygous alleles of qCTS11.1 and qCTS11.2 from ‘Nipponbare’ showed major positive effects on cold tolerance. Through pyramiding the linked QTLs in the cold‐sensitive Indica rice cultivar ‘93‐11’, we have developed a new elite, high‐yielding Indica variety with cold tolerance.     

白菜型油菜WRKY基因片段的克隆与表达分析

WRKY转录因子能广泛地参与植物的生物与非生物胁迫反应。为了研究WRKY转录因子在ABA诱导下的表达调控,首先利用同源克隆法在白菜型油菜中克隆WRKY基因和Actin基因片段, 用BLAST和DNAMAN软件对核酸及氨基酸序列进行分析;通过荧光定量PCR技术检测白菜型油菜WRKY基因在ABA处理条件下的相对表达趋势;然后利用相对定量PCR技术（real-time relative quantification PCR,以下简称RT-qPCR）检测WRKY基因在ABA(100 μM)诱导不同时段的差异表达。在白菜型油菜中克隆到一段中克隆到一段长度为680 bp的WRKY基因片段和一段长度为933 bp的β-actin基因片段。RT-qPCR实验结果表明,BcWRKY能被ABA诱导表达,且在诱导1 h后表达量最高。本实验文成功地克隆了白菜型油菜的WRKY转录因子基因和Actin基因片段,并证明了白菜型油菜WRKY基因的表达受ABA的影响。     

连续流动法测定烟草中的挥发酚

建立一种测定烟草及烟草制品的连续流动方法,烟草浸提液在155℃,磷酸条件下蒸馏,挥发酚与4-氨基安替吡啉和铁氰化钾反应,在pH等于10.0,生成一种红色物质,其最大吸收波长为505nm。结果表明：在标准溶液浓度为0-6.0mg/L 的范围,有良好的线性关系,相关系数r为0.9996,方法的检出限(s/n=3)为3.9ug/L,平均回收率为98.5%-101.1%,相对标准偏差(RSD)为1.9%(n=10)。     

晋城市农业 农村信息化建设存在的问题及对策

论述了山西省晋城市农业、农村信息化建设的现状,取得的成效,以及存在的问题,提出了加强农业、农村信息化建设的对策和建议。     

Negotiating ‘home’ and ‘national identity’: Chinese‐Malaysian transmigrants in Singapore

Abstract: Part of the globalisation phenomenon involves an increasing number of elite transmigrants traversing national boundaries in response to the global demand for skilled labour while maintaining multifaceted social ties astride political, geographic and cultural borders, linking home and host countries together. As transmigrants ‘live’ in several communities simultaneously, their identities, behaviour and values are often not limited by location. Thus, notions of ‘home’ and ‘national identity’ are also being reviewed given the discrepancies between these concepts and locality. In this context, this paper explores questions of ‘home’ and ‘national identity’ among skilled Chinese‐Malaysians working and residing in Singapore, portraying them as active participants of two (or more) countries. It focuses on their strategies and struggles in negotiating ideologies of ‘home’ and ‘national identities’ across borders in a setting of two neighbouring countries umbilically linked in a volatile political relationship. It further examines their degree of concern in the political affairs of both countries. Between ‘home’ and ‘host’, Chinese‐Malaysians redefine their practices of home(‐making) in relation to their national identity, drawing on the resources and resilience of familial ties, nostalgic memories and other practical lifecourse needs.     

Between ‘state’ and ‘society’: Commune authorities and the environment in Vietnam's craft villages

Maintaining a liveable environment in Vietnam's polluted craft villages is a daily challenge for state authorities and residents. Neighbouring urban populations demand that the state effectively curtails and manages pollution, while local residents prioritise their livelihoods and routinely flout regulations. The commune official, tasked with the seemingly impossible task of environmental regulation, occupies a fraught position, torn between the imperatives and constraints of craft producers and state regulatory demands. This study of water pollution in northern Vietnam's craft villages finds that commune officials' conflicted role in environmental governance is a central factor in the failure of the current environmental governance regime, and reflects the internally conflicted nature of the Vietnamese state.     

Non-destructive monitoring of flesh softening in the black-skinned Japanese plums ‘Angeleno’ and ‘Autumn beaut’ on-tree and postharvest

There is a need to develop alternative harvest indexes for black skinned plums. The aim of this research was to analyze and compare the most commonly used indexes for deciding the harvest date for Japanese plum, and evaluate the effectiveness of new approaches for studying maturation. The ripening process was monitored on-tree and during postharvest in a non-destructive way, through the absorbance of chlorophyll (I_AD), the compression strength of the intact fruit, and the traditional parameters associated with ripening. Fruit were harvested at commercial ripeness and “tree-ripe”, and were stored for 10 d at 22 °C and 75-80% RH. The I_AD decreased during the last phase of development of the fruit on-tree, and it was related to the common indexes used for plums. ‘Angeleno’ showed a decrease of the I_AD 24% lower than that observed for ‘Autumn beaut’. The I_AD versus time showed the highest coefficients of determination when compared with the soluble solids concentration (SSC), flesh firmness, hue (H°) and chroma (C*) of the skin. The compression strength of the intact fruit was associated with flesh firmness, and to a lesser extent with the SSC for ‘Angeleno’, whereas for ‘Autumn beaut’ higher correlations for both the SSC and flesh firmness were observed. The C* of the skin on ‘Autumn beaut’ showed an erratic change during ripening; by contrast, for ‘Angeleno’, this index showed a clear trend. During postharvest it was observed that for ‘Angeleno’ fruit picked at commercial ripeness, the rate of change of the I_AD was practically the same as observed on-tree, while for ‘Autumn beaut’ the rates of change on-tree and at postharvest were 0.075 I_AD d⁻¹ and 0.024 I_AD d⁻¹, respectively. For the “tree-ripe” fruit, the rate of change was practically the same for both cultivars. Similar trends were observed for the compression strength.